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Ashutosh Chilkoti

Alan L. Kaganov Distinguished Professor of Biomedical Engineering
Biomedical Engineering
Box 90281, Durham, NC 27708-0281
3381 Ciemas, Durham, NC 27708

Selected Publications


Encoding Structure in Intrinsically Disordered Protein Biomaterials.

Journal Article Accounts of chemical research · February 2024 ConspectusIn nature, proteins range from those with highly ordered secondary and tertiary structures to those that completely lack a well-defined three-dimensional structure, termed intrinsically disordered proteins (IDPs). IDPs are generally characterized ... Full text Cite

Enzymatic Synthesis of Aptamer-Polynucleotide Nanoparticles with High Anticancer Drug Loading for Targeted Delivery.

Journal Article Biomacromolecules · January 2024 We report a targeted prodrug delivery platform that can deliver a cytostatic nucleobase analog with high drug loading. We chose fluorouracil (5FU), a drug used to treat various cancers, whose active metabolite 5-fluorodeoxyuridine monophosphate (5-FdUMP) i ... Full text Cite

Modulating hierarchical self-assembly in thermoresponsive intrinsically disordered proteins through high-temperature incubation time.

Journal Article Scientific reports · December 2023 The cornerstone of structural biology is the unique relationship between protein sequence and the 3D structure at equilibrium. Although intrinsically disordered proteins (IDPs) do not fold into a specific 3D structure, breaking this paradigm, some IDPs exh ... Full text Cite

Immune-active polymeric materials for the treatment of inflammatory diseases

Journal Article Current Opinion in Colloid and Interface Science · October 1, 2023 In recent years, a growing understanding of the underlying mechanisms of autoinflammatory and autoimmune disease has enabled significant advances in biomaterial therapeutics for their treatment and prevention. Drug-free or immune-active polymeric materials ... Full text Cite

Plasmonic Fluorescence Enhancement in Diagnostics for Clinical Tests at Point-of-Care: A Review of Recent Technologies.

Journal Article Advanced materials (Deerfield Beach, Fla.) · August 2023 Fluorescence-based biosensors have widely been used in the life-sciences and biomedical applications due to their low limit of detection and a diverse selection of fluorophores that enable simultaneous measurements of multiple biomarkers. Recent research e ... Full text Cite

A gravity-driven droplet fluidic point-of-care test.

Journal Article Device · July 2023 We report a simple droplet fluidic point-of-care test (POCT) that uses gravity to manipulate the sequence, timing, and motion of droplets on a surface. To fabricate this POCT, we first developed a surface coating toolbox of nine different coatings with thr ... Full text Cite

Environmentally Resilient Microfluidic Point-of-Care Immunoassay Enables Rapid Diagnosis of Talaromycosis.

Journal Article ACS Sens · June 23, 2023 Point-of-care tests (POCTs) are increasingly being used in field settings, particularly outdoors. The performance of current POCTs─most commonly the lateral flow immunoassay─can be adversely affected by ambient temperature and humidity. We developed a self ... Full text Link to item Cite

Interface of biomolecular condensates modulates redox reactions.

Journal Article Chem · June 2023 Biomolecular condensates mediate diverse cellular processes. The density transition process of condensate formation results in selective partitioning of molecules, which define a distinct chemical environment within the condensates. However, the fundamenta ... Full text Cite

Engineering Innovative Interfaces for Point-of-Care Diagnostics.

Journal Article Current opinion in colloid & interface science · June 2023 The ongoing Coronavirus disease 2019 (COVID-19) pandemic illustrates the need for sensitive and reliable tools to diagnose and monitor diseases. Traditional diagnostic approaches rely on centralized laboratory tests that result in long wait times to result ... Full text Cite

COVID-19 Diagnosis and SARS-CoV-2 Strain Identification by a Rapid, Multiplexed, Point-of-Care Antibody Microarray.

Journal Article Anal Chem · April 4, 2023 Antigen tests to detect SARS-CoV-2 have emerged as a promising rapid diagnostic method for COVID-19, but they are unable to differentiate between variants of concern (VOCs). Here, we report a rapid point-of-care test (POC-T), termed CoVariant-SPOT, that us ... Full text Open Access Link to item Cite

Programmable synthetic biomolecular condensates for cellular control.

Journal Article Nature chemical biology · April 2023 The formation of biomolecular condensates mediated by a coupling of associative and segregative phase transitions plays a critical role in controlling diverse cellular functions in nature. This has inspired the use of phase transitions to design synthetic ... Full text Cite

An injectable PEG-like conjugate forms a subcutaneous depot and enables sustained delivery of a peptide drug.

Journal Article Biomaterials · March 2023 Many biologics have a short plasma half-life, and their conjugation to polyethylene glycol (PEG) is commonly used to solve this problem. However, the improvement in the plasma half-life of PEGylated drugs' is at an asymptote because the development of bran ... Full text Link to item Cite

Mixed-surface polyamidoamine polymer variants retain nucleic acid-scavenger ability with reduced toxicity.

Journal Article iScience · December 22, 2022 Nucleic acid-binding polymers can have anti-inflammatory properties and beneficial effects in animal models of infection, trauma, cancer, and autoimmunity. PAMAM G3, a polyamidoamine dendrimer, is fully cationic bearing 32 protonable surface amines. Howeve ... Full text Link to item Cite

Brachytherapy via a depot of biopolymer-bound 131I synergizes with nanoparticle paclitaxel in therapy-resistant pancreatic tumours.

Journal Article Nat Biomed Eng · October 2022 Locally advanced pancreatic tumours are highly resistant to conventional radiochemotherapy. Here we show that such resistance can be surmounted by an injectable depot of thermally responsive elastin-like polypeptide (ELP) conjugated with iodine-131 radionu ... Full text Open Access Link to item Cite

Double-stranded RNA drives SARS-CoV-2 nucleocapsid protein to undergo phase separation at specific temperatures.

Journal Article Nucleic Acids Res · August 12, 2022 Nucleocapsid protein (N-protein) is required for multiple steps in betacoronaviruses replication. SARS-CoV-2-N-protein condenses with specific viral RNAs at particular temperatures making it a powerful model for deciphering RNA sequence specificity in cond ... Full text Link to item Cite

Genetically Engineered Nanoparticles of Asymmetric Triblock Polypeptide with a Platinum(IV) Cargo Outperforms a Platinum(II) Analog and Free Drug in a Murine Cancer Model.

Journal Article Nano Lett · July 27, 2022 The development of platinum(Pt)-drugs for cancer therapy has stalled, as no new Pt-drugs have been approved in over a decade. Packaging small molecule drugs into nanoparticles is a way to enhance their therapeutic efficacy. To date, there has been no direc ... Full text Link to item Cite

P2RY2-AKT activation is a therapeutically actionable consequence of XPO1 inhibition in acute myeloid leukemia.

Journal Article Nat Cancer · July 2022 Selinexor is a first-in-class inhibitor of the nuclear exportin XPO1 that was recently approved by the US Food and Drug Administration for the treatment of multiple myeloma and diffuse large B-cell lymphoma. In relapsed/refractory acute myeloid leukemia (A ... Full text Link to item Cite

Technologies for Frugal and Sensitive Point-of-Care Immunoassays.

Journal Article Annual review of analytical chemistry (Palo Alto, Calif.) · June 2022 Immunoassays are a powerful tool for sensitive and quantitative analysis of a wide range of biomolecular analytes in the clinic and in research laboratories. However, enzyme-linked immunosorbent assay (ELISA)-the gold-standard assay-requires significant us ... Full text Cite

Genetically encoded elastin-like polypeptide nanoparticles for drug delivery.

Journal Article Current opinion in biotechnology · April 2022 Small molecule drugs suffer from poor in vivo half-life, rapid degradation, and systemic off-target toxicity. To address these issues, researchers have developed nanoparticles that significantly enhance the delivery of many drugs while reducing their toxic ... Full text Cite

Polyethylene Glycol-Like Brush Polymer Conjugate of a Protein Drug Does Not Induce an Antipolymer Immune Response and Has Enhanced Pharmacokinetics than Its Polyethylene Glycol Counterpart.

Journal Article Adv Sci (Weinh) · April 2022 Protein therapeutics, except for antibodies, have a short plasma half-life and poor stability in circulation. Covalent coupling of polyethylene glycol (PEG) to protein drugs addresses this limitation. However, unlike previously thought, PEG is immunogenic. ... Full text Link to item Cite

Encoding Structure in Intrinsically Disordered Protein Biomaterials.

Journal Article Accounts of chemical research · February 2024 ConspectusIn nature, proteins range from those with highly ordered secondary and tertiary structures to those that completely lack a well-defined three-dimensional structure, termed intrinsically disordered proteins (IDPs). IDPs are generally characterized ... Full text Cite

Enzymatic Synthesis of Aptamer-Polynucleotide Nanoparticles with High Anticancer Drug Loading for Targeted Delivery.

Journal Article Biomacromolecules · January 2024 We report a targeted prodrug delivery platform that can deliver a cytostatic nucleobase analog with high drug loading. We chose fluorouracil (5FU), a drug used to treat various cancers, whose active metabolite 5-fluorodeoxyuridine monophosphate (5-FdUMP) i ... Full text Cite

Modulating hierarchical self-assembly in thermoresponsive intrinsically disordered proteins through high-temperature incubation time.

Journal Article Scientific reports · December 2023 The cornerstone of structural biology is the unique relationship between protein sequence and the 3D structure at equilibrium. Although intrinsically disordered proteins (IDPs) do not fold into a specific 3D structure, breaking this paradigm, some IDPs exh ... Full text Cite

Immune-active polymeric materials for the treatment of inflammatory diseases

Journal Article Current Opinion in Colloid and Interface Science · October 1, 2023 In recent years, a growing understanding of the underlying mechanisms of autoinflammatory and autoimmune disease has enabled significant advances in biomaterial therapeutics for their treatment and prevention. Drug-free or immune-active polymeric materials ... Full text Cite

Plasmonic Fluorescence Enhancement in Diagnostics for Clinical Tests at Point-of-Care: A Review of Recent Technologies.

Journal Article Advanced materials (Deerfield Beach, Fla.) · August 2023 Fluorescence-based biosensors have widely been used in the life-sciences and biomedical applications due to their low limit of detection and a diverse selection of fluorophores that enable simultaneous measurements of multiple biomarkers. Recent research e ... Full text Cite

A gravity-driven droplet fluidic point-of-care test.

Journal Article Device · July 2023 We report a simple droplet fluidic point-of-care test (POCT) that uses gravity to manipulate the sequence, timing, and motion of droplets on a surface. To fabricate this POCT, we first developed a surface coating toolbox of nine different coatings with thr ... Full text Cite

Environmentally Resilient Microfluidic Point-of-Care Immunoassay Enables Rapid Diagnosis of Talaromycosis.

Journal Article ACS Sens · June 23, 2023 Point-of-care tests (POCTs) are increasingly being used in field settings, particularly outdoors. The performance of current POCTs─most commonly the lateral flow immunoassay─can be adversely affected by ambient temperature and humidity. We developed a self ... Full text Link to item Cite

Interface of biomolecular condensates modulates redox reactions.

Journal Article Chem · June 2023 Biomolecular condensates mediate diverse cellular processes. The density transition process of condensate formation results in selective partitioning of molecules, which define a distinct chemical environment within the condensates. However, the fundamenta ... Full text Cite

Engineering Innovative Interfaces for Point-of-Care Diagnostics.

Journal Article Current opinion in colloid & interface science · June 2023 The ongoing Coronavirus disease 2019 (COVID-19) pandemic illustrates the need for sensitive and reliable tools to diagnose and monitor diseases. Traditional diagnostic approaches rely on centralized laboratory tests that result in long wait times to result ... Full text Cite

COVID-19 Diagnosis and SARS-CoV-2 Strain Identification by a Rapid, Multiplexed, Point-of-Care Antibody Microarray.

Journal Article Anal Chem · April 4, 2023 Antigen tests to detect SARS-CoV-2 have emerged as a promising rapid diagnostic method for COVID-19, but they are unable to differentiate between variants of concern (VOCs). Here, we report a rapid point-of-care test (POC-T), termed CoVariant-SPOT, that us ... Full text Open Access Link to item Cite

Programmable synthetic biomolecular condensates for cellular control.

Journal Article Nature chemical biology · April 2023 The formation of biomolecular condensates mediated by a coupling of associative and segregative phase transitions plays a critical role in controlling diverse cellular functions in nature. This has inspired the use of phase transitions to design synthetic ... Full text Cite

An injectable PEG-like conjugate forms a subcutaneous depot and enables sustained delivery of a peptide drug.

Journal Article Biomaterials · March 2023 Many biologics have a short plasma half-life, and their conjugation to polyethylene glycol (PEG) is commonly used to solve this problem. However, the improvement in the plasma half-life of PEGylated drugs' is at an asymptote because the development of bran ... Full text Link to item Cite

Mixed-surface polyamidoamine polymer variants retain nucleic acid-scavenger ability with reduced toxicity.

Journal Article iScience · December 22, 2022 Nucleic acid-binding polymers can have anti-inflammatory properties and beneficial effects in animal models of infection, trauma, cancer, and autoimmunity. PAMAM G3, a polyamidoamine dendrimer, is fully cationic bearing 32 protonable surface amines. Howeve ... Full text Link to item Cite

Brachytherapy via a depot of biopolymer-bound 131I synergizes with nanoparticle paclitaxel in therapy-resistant pancreatic tumours.

Journal Article Nat Biomed Eng · October 2022 Locally advanced pancreatic tumours are highly resistant to conventional radiochemotherapy. Here we show that such resistance can be surmounted by an injectable depot of thermally responsive elastin-like polypeptide (ELP) conjugated with iodine-131 radionu ... Full text Open Access Link to item Cite

Double-stranded RNA drives SARS-CoV-2 nucleocapsid protein to undergo phase separation at specific temperatures.

Journal Article Nucleic Acids Res · August 12, 2022 Nucleocapsid protein (N-protein) is required for multiple steps in betacoronaviruses replication. SARS-CoV-2-N-protein condenses with specific viral RNAs at particular temperatures making it a powerful model for deciphering RNA sequence specificity in cond ... Full text Link to item Cite

Genetically Engineered Nanoparticles of Asymmetric Triblock Polypeptide with a Platinum(IV) Cargo Outperforms a Platinum(II) Analog and Free Drug in a Murine Cancer Model.

Journal Article Nano Lett · July 27, 2022 The development of platinum(Pt)-drugs for cancer therapy has stalled, as no new Pt-drugs have been approved in over a decade. Packaging small molecule drugs into nanoparticles is a way to enhance their therapeutic efficacy. To date, there has been no direc ... Full text Link to item Cite

P2RY2-AKT activation is a therapeutically actionable consequence of XPO1 inhibition in acute myeloid leukemia.

Journal Article Nat Cancer · July 2022 Selinexor is a first-in-class inhibitor of the nuclear exportin XPO1 that was recently approved by the US Food and Drug Administration for the treatment of multiple myeloma and diffuse large B-cell lymphoma. In relapsed/refractory acute myeloid leukemia (A ... Full text Link to item Cite

Technologies for Frugal and Sensitive Point-of-Care Immunoassays.

Journal Article Annual review of analytical chemistry (Palo Alto, Calif.) · June 2022 Immunoassays are a powerful tool for sensitive and quantitative analysis of a wide range of biomolecular analytes in the clinic and in research laboratories. However, enzyme-linked immunosorbent assay (ELISA)-the gold-standard assay-requires significant us ... Full text Cite

Genetically encoded elastin-like polypeptide nanoparticles for drug delivery.

Journal Article Current opinion in biotechnology · April 2022 Small molecule drugs suffer from poor in vivo half-life, rapid degradation, and systemic off-target toxicity. To address these issues, researchers have developed nanoparticles that significantly enhance the delivery of many drugs while reducing their toxic ... Full text Cite

Polyethylene Glycol-Like Brush Polymer Conjugate of a Protein Drug Does Not Induce an Antipolymer Immune Response and Has Enhanced Pharmacokinetics than Its Polyethylene Glycol Counterpart.

Journal Article Adv Sci (Weinh) · April 2022 Protein therapeutics, except for antibodies, have a short plasma half-life and poor stability in circulation. Covalent coupling of polyethylene glycol (PEG) to protein drugs addresses this limitation. However, unlike previously thought, PEG is immunogenic. ... Full text Link to item Cite

PEG-Like Brush Polymer Conjugate of RNA Aptamer That Shows Reversible Anticoagulant Activity and Minimal Immune Response.

Journal Article Adv Mater · March 2022 Ribonucleic acid (RNA) therapeutics are an emerging class of drugs. RNA aptamers are of significant therapeutic and clinical interest because their activity can be easily reversed in vivo-a useful feature that is difficult to achieve using other therapeuti ... Full text Link to item Cite

Intratumoral delivery of brachytherapy and immunotherapy by a thermally triggered polypeptide depot.

Journal Article J Control Release · March 2022 Biomaterial-based approaches for a combination of radiotherapy and immunotherapy can improve outcomes in metastatic cancer through local delivery of both therapeutic modalities to the primary tumor to control local tumor growth and distant metastases. This ... Full text Link to item Cite

Smartphone Enabled Point-of-Care Detection of Serum Biomarkers.

Journal Article Methods in molecular biology (Clifton, N.J.) · January 2022 Sandwich immunoassays are the gold standard for detection of protein analytes. Here, we describe an ultrasensitive point-of-care sandwich immunoassay platform for the detection of biomarkers directly from blood or serum using a custom-built smartphone dete ... Full text Cite

Rapid test to assess the escape of SARS-CoV-2 variants of concern.

Journal Article Sci Adv · December 3, 2021 Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants are concerning in the ongoing coronavirus disease 2019 (COVID-19) pandemic. Here, we developed a rapid test, termed CoVariant-SCAN, that detects neutralizing antibodies (nAbs) capable of ... Full text Link to item Cite

Concentration-Independent Multivalent Targeting of Cancer Cells by Genetically Encoded Core-Crosslinked Elastin/Resilin-like Polypeptide Micelles.

Journal Article Biomacromolecules · October 2021 Valency is a fundamental principle to control macromolecular interactions and is used to target specific cell types by multivalent ligand-receptor interactions using self-assembled nanoparticle carriers. At the concentrations encountered in solid tumors up ... Full text Cite

Microphase Separation of Resilin-like and Elastin-like Diblock Copolypeptides in Concentrated Solutions.

Journal Article Biomacromolecules · September 2021 Diblock copolymers are valued for their ability to form thin films with nanoscale features that typically reflect those of their microphase-separated structures in concentrated solution. Here, we show that such self-assembled structures can be easily forme ... Full text Cite

Cellphone enabled point-of-care assessment of breast tumor cytology and molecular HER2 expression from fine-needle aspirates.

Journal Article NPJ Breast Cancer · July 2, 2021 Management of breast cancer in limited-resource settings is hindered by a lack of low-cost, logistically sustainable approaches toward molecular and cellular diagnostic pathology services that are needed to guide therapy. To address these limitations, we h ... Full text Link to item Cite

Genetically Encoded Elastin-Like Polypeptides for Drug Delivery.

Journal Article Advanced healthcare materials · July 2021 Elastin-like polypeptides (ELPs) are thermally responsive biopolymers that consist of a repeated amino acid motif derived from human tropoelastin. These peptides exhibit temperature-dependent phase behavior that can be harnessed to produce stimuli-responsi ... Full text Cite

Protein Phase Separation Arising from Intrinsic Disorder: First-Principles to Bespoke Applications.

Journal Article The journal of physical chemistry. B · July 2021 The phase separation of biomolecules has become the focus of intense research in the past decade, with a growing body of research implicating this phenomenon in essentially all biological functions, including but not limited to homeostasis, stress response ... Full text Cite

Multiplexed, quantitative serological profiling of COVID-19 from blood by a point-of-care test.

Journal Article Sci Adv · June 2021 Highly sensitive, specific, and point-of-care (POC) serological assays are an essential tool to manage coronavirus disease 2019 (COVID-19). Here, we report on a microfluidic POC test that can profile the antibody response against multiple severe acute resp ... Full text Link to item Cite

Ultrasensitive point-of-care immunoassay for secreted glycoprotein detects Ebola infection earlier than PCR.

Journal Article Sci Transl Med · April 7, 2021 Ebola virus (EBOV) hemorrhagic fever outbreaks have been challenging to deter due to the lack of health care infrastructure in disease-endemic countries and a corresponding inability to diagnose and contain the disease at an early stage. EBOV vaccines and ... Full text Link to item Cite

Modular complement assemblies for mitigating inflammatory conditions.

Journal Article Proceedings of the National Academy of Sciences of the United States of America · April 2021 Complement protein C3dg, a key linkage between innate and adaptive immunity, is capable of stimulating both humoral and cell-mediated immune responses, leading to considerable interest in its use as a molecular adjuvant. However, the potential of C3dg as a ... Full text Cite

Nanoscopic Dynamics Dictate the Phase Separation Behavior of Intrinsically Disordered Proteins.

Journal Article Biomacromolecules · February 2021 Many intrinsically disordered proteins (IDPs) in nature may undergo liquid-liquid phase separation to assemble membraneless organelles with varied liquid-like properties and stability/dynamics. While solubility changes underlie these properties, little is ... Full text Cite

Design of intrinsically disordered proteins that undergo phase transitions with lower critical solution temperatures.

Journal Article APL materials · February 2021 Many naturally occurring elastomers are intrinsically disordered proteins (IDPs) built up of repeating units and they can demonstrate two types of thermoresponsive phase behavior. Systems characterized by lower critical solution temperatures (LCST) undergo ... Full text Cite

Rapid capture of biomolecules from blood via stimuli-responsive elastomeric particles for acoustofluidic separation.

Journal Article The Analyst · January 2021 The detection of biomarkers in blood often requires extensive and time-consuming sample preparation to remove blood cells and concentrate the biomarker(s) of interest. We demonstrate proof-of-concept for a chip-based, acoustofluidic method that enables the ... Full text Cite

Recombinant Fusion of Glucagon-Like Peptide-1 and an Albumin Binding Domain Provides Glycemic Control for a Week in Diabetic Mice

Journal Article Advanced Therapeutics · October 1, 2020 Glucagon-like peptide-1 (GLP1) is an intestinally derived incretin currently under investigation for treatment of type 2 diabetes. The clinical application of GLP1 is limited by its short half-life, which necessitates frequent administration. To address th ... Full text Cite

Tumor Subtype Determines Therapeutic Response to Chimeric Polypeptide Nanoparticle-based Chemotherapy in Pten-deleted Mouse Models of Sarcoma.

Journal Article Clin Cancer Res · September 15, 2020 PURPOSE: Nanoparticle-encapsulated drug formulations can improve responses to conventional chemotherapy by increasing drug retention within the tumor and by promoting a more effective antitumor immune response than free drug. New drug delivery modalities a ... Full text Link to item Cite

De novo engineering of intracellular condensates using artificial disordered proteins.

Journal Article Nature chemistry · September 2020 Phase separation of intrinsically disordered proteins (IDPs) is a remarkable feature of living cells to dynamically control intracellular partitioning. Despite the numerous new IDPs that have been identified, progress towards rational engineering in cells ... Full text Cite

Sustained release of a GLP-1 and FGF21 dual agonist from an injectable depot protects mice from obesity and hyperglycemia.

Journal Article Sci Adv · August 2020 There is great interest in identifying a glucagon-like peptide-1 (GLP-1)-based combination therapy that will more effectively promote weight loss in patients with type 2 diabetes. Fibroblast growth factor 21 (FGF21) is a compelling yet previously unexplore ... Full text Link to item Cite

Connecting Coil-to-Globule Transitions to Full Phase Diagrams for Intrinsically Disordered Proteins.

Journal Article Biophysical journal · July 2020 Phase separation is thought to underlie spatial and temporal organization that is required for controlling biochemical reactions in cells. Multivalence of interaction motifs, also known as stickers, is a defining feature of proteins that drive phase separa ... Full text Cite

Elastin-Like Polypeptides for Biomedical Applications.

Journal Article Annual review of biomedical engineering · June 2020 Elastin-like polypeptides (ELPs) are stimulus-responsive biopolymers derived from human elastin. Their unique properties-including lower critical solution temperature phase behavior and minimal immunogenicity-make them attractive materials for a variety of ... Full text Cite

Ultrabright Fluorescence Readout of an Inkjet-Printed Immunoassay Using Plasmonic Nanogap Cavities.

Journal Article Nano letters · June 2020 Fluorescence-based microarrays are promising diagnostic tools due to their high throughput, small sample volume requirements, and multiplexing capabilities. However, their low fluorescence output has limited their implementation for in vitro diagnos ... Full text Cite

Genetically Encoded Stealth Nanoparticles of a Zwitterionic Polypeptide-Paclitaxel Conjugate Have a Wider Therapeutic Window than Abraxane in Multiple Tumor Models.

Journal Article Nano Lett · April 8, 2020 Small-molecule therapeutics demonstrate suboptimal pharmacokinetics and bioavailability due to their hydrophobicity and size. One way to overcome these limitations-and improve their efficacy-is to use "stealth" macromolecular carriers that evade uptake by ... Full text Link to item Cite

Complex microparticle architectures from stimuli-responsive intrinsically disordered proteins.

Journal Article Nature communications · March 2020 The controllable production of microparticles with complex geometries is useful for a variety of applications in materials science and bioengineering. The formation of intricate microarchitectures typically requires sophisticated fabrication techniques suc ... Full text Cite

Aerosol jet printing of biological inks by ultrasonic delivery.

Journal Article Biofabrication · February 2020 Printing is a promising method to reduce the cost of fabricating biomedical devices. While there have been significant advancements in direct-write printing techniques, non-contact printing of biological reagents has been almost exclusively limited to inkj ... Full text Cite

In Pursuit of Zero 2.0: Recent Developments in Nonfouling Polymer Brushes for Immunoassays.

Journal Article Advanced materials (Deerfield Beach, Fla.) · January 2020 "Nonfouling" polymer brush surfaces can greatly improve the performance of in vitro diagnostic (IVD) assays due to the reduction of nonspecific protein adsorption and consequent improvement of signal-to-noise ratios. The development of synthetic polymer br ... Full text Cite

Quantitative Study of the Interaction of Multivalent Ligand-Modified Nanoparticles with Breast Cancer Cells with Tunable Receptor Density.

Journal Article ACS nano · January 2020 Multivalent nanoparticles that target a cell surface receptor that is overexpressed by cancer cells are a promising delivery system for cancer therapy. However, the impact of the receptor density and nanoparticle ligand valency on the cell uptake has not b ... Full text Cite

Recent trends in protein and peptide-based biomaterials for advanced drug delivery.

Journal Article Advanced drug delivery reviews · January 2020 Engineering protein and peptide-based materials for drug delivery applications has gained momentum due to their biochemical and biophysical properties over synthetic materials, including biocompatibility, ease of synthesis and purification, tunability, sca ... Full text Cite

Surface Patterning

Chapter · January 1, 2020 Surface patterning becomes an important tool in biomedical research and applications, as it enables systematic investigation of cell-biomaterial interaction as well as rapid, high-throughput tests for disease diagnosis and drug screening. Recent advances i ... Full text Cite

Heuristics for the Optimal Presentation of Bioactive Peptides on Polypeptide Micelles.

Journal Article Nano letters · November 2019 Bioactive peptides describe a very large group of compounds with diverse functions and wide applications, and their multivalent display by nanoparticles can maximize their activities. However, the lack of a universal nanoparticle platform and design rules ... Full text Cite

Nature of Amorphous Hydrophilic Block Affects Self-Assembly of an Artificial Viral Coat Polypeptide.

Journal Article Biomacromolecules · October 2019 Consensus motifs for sequences of both crystallizable and amorphous blocks in silks and natural structural analogues of silks vary widely. To design novel silklike polypeptides, an important question is therefore how the nature of either the crystallizable ... Full text Cite

Versatile biomanufacturing through stimulus-responsive cell-material feedback.

Journal Article Nature chemical biology · October 2019 Small-scale production of biologics has great potential for enhancing the accessibility of biomanufacturing. By exploiting cell-material feedback, we have designed a concise platform to achieve versatile production, analysis and purification of diverse pro ... Full text Cite

Intrinsically disordered proteins access a range of hysteretic phase separation behaviors.

Journal Article Science advances · October 2019 The phase separation behavior of intrinsically disordered proteins (IDPs) is thought of as analogous to that of polymers that undergo equilibrium lower or upper critical solution temperature (LCST and UCST, respectively) phase transition. This view, howeve ... Full text Cite

Avidity and Cell Uptake of Integrin-Targeting Polypeptide Micelles is Strongly Shape-Dependent.

Journal Article Nano letters · September 2019 We describe a genetically encoded micelle for targeted delivery consisting of a diblock polypeptide with segments derived from repetitive protein motifs inspired by Drosophila melanogaster Rec-1 resilin and human tropoelastin with a C-terminal fusio ... Full text Cite

Genomically informed small-molecule drugs overcome resistance to a sustained-release formulation of an engineered death receptor agonist in patient-derived tumor models.

Journal Article Sci Adv · September 2019 Extrinsic pathway agonists have failed repeatedly in the clinic for three core reasons: Inefficient ligand-induced receptor multimerization, poor pharmacokinetic properties, and tumor intrinsic resistance. Here, we address these factors by (i) using a high ... Full text Link to item Cite

Engineered Ribonucleoprotein Granules Inhibit Translation in Protocells.

Journal Article Molecular cell · July 2019 Liquid granules rich in intrinsically disordered proteins and RNA play key roles in critical cellular functions such as RNA processing and translation. Many details of the mechanism via which this occurs remain to be elucidated. Motivated by the lacuna in ... Full text Cite

Molecular and Materials Engineering for Delivery of Peptide Drugs to Treat Type 2 Diabetes.

Journal Article Advanced healthcare materials · June 2019 Type 2 diabetes is exploding globally. Despite numerous treatment options, nearly half of type 2 diabetics are unsuccessful at properly managing the disease, primarily due to a lack of patient compliance, driven by adverse side effects as well as complicat ... Full text Cite

Inducible Fibril Formation of Silk-Elastin Diblocks.

Journal Article ACS omega · May 2019 Silk-elastin block copolymers have such physical and biological properties that make them attractive biomaterials for applications ranging from tissue regeneration to drug delivery. Silk-elastin block copolymers that only assemble into fibrils at high conc ... Full text Cite

Architectural Modification of Conformal PEG-Bottlebrush Coatings Minimizes Anti-PEG Antigenicity While Preserving Stealth Properties.

Journal Article Adv Healthc Mater · April 2019 Poly(ethylene glycol) (PEG), a linear polymer known for its "stealth" properties, is commonly used to passivate the surface of biomedical implants and devices, and it is conjugated to biologic drugs to improve their pharmacokinetics. However, its antigenic ... Full text Link to item Cite

Sediment challenge to promising ultra-low fouling hydrophilic surfaces in the marine environment.

Journal Article Biofouling · April 2019 Hydrophilic coatings exhibit ultra-low fouling properties in numerous laboratory experiments. In stark contrast, the antifouling effect of such coatings in vitro failed when performing field tests in the marine environment. The fouling release perfo ... Full text Cite

Conjugate of Doxorubicin to Albumin-Binding Peptide Outperforms Aldoxorubicin.

Journal Article Small (Weinheim an der Bergstrasse, Germany) · March 2019 Short circulation time and off-target toxicity are the main challenges faced by small-molecule chemotherapeutics. To overcome these shortcomings, an albumin-binding peptide conjugate of chemotherapeutics is developed that binds specifically to endogenous a ... Full text Cite

Engineering the Surface Properties of a Zwitterionic Polymer Brush to Enable the Simple Fabrication of Inkjet-Printed Point-of-Care Immunoassays.

Journal Article Langmuir : the ACS journal of surfaces and colloids · February 2019 Motivated by the lack of adventitious protein adsorption on zwitterionic polymer brushes that promise low noise and hence high analytical sensitivity for surface-based immunoassays, we explored their use as a substrate for immunoassay fabrication by the in ... Full text Cite

Long circulating genetically encoded intrinsically disordered zwitterionic polypeptides for drug delivery.

Journal Article Biomaterials · February 2019 The clinical utility of many peptide and protein drugs is limited by their short in-vivo half-life. To address this limitation, we report a new class of polypeptide-based materials that have a long plasma circulation time. The design of these polypeptides ... Full text Cite

Active Targeting of Cancer Cells by Nanobody Decorated Polypeptide Micelle with Bio-orthogonally Conjugated Drug.

Journal Article Nano letters · January 2019 Polypeptides are promising carriers for chemotherapeutics: they have minimal toxicity, can be recombinantly synthesized with precise control over molecular weight, and enhance drug pharmacokinetics as self-assembled nanoparticles. Polypeptide-based systems ... Full text Cite

Genetically Encoded Cholesterol-Modified Polypeptides.

Journal Article Journal of the American Chemical Society · January 2019 Biological systems use post-translational modifications (PTMs) to control the structure, location, and function of proteins after expression. Despite the ubiquity of PTMs in biology, their use to create genetically encoded recombinant biomaterials is limit ... Full text Cite

Enzymatic synthesis and modification of high molecular weight DNA using terminal deoxynucleotidyl transferase.

Chapter · January 2019 The recognition that nucleic acids can be used as polymeric materials led to the blossoming of the field of DNA nanotechnology, with a broad range of applications in biotechnology, biosensors, diagnostics, and drug delivery. These applications require effi ... Full text Cite

Injectable tissue integrating networks from recombinant polypeptides with tunable order.

Journal Article Nat Mater · December 2018 Emergent properties of natural biomaterials result from the collective effects of nanoscale interactions among ordered and disordered domains. Here, using recombinant sequence design, we have created a set of partially ordered polypeptides to study emergen ... Full text Link to item Cite

Author Correction: Injectable tissue integrating networks from recombinant polypeptides with tunable order.

Journal Article Nat Mater · December 2018 In the version of this Article originally published, one of the authors' names was incorrectly given as Jeffery Schaal; it should have been Jeffrey L. Schaal. This has been corrected in all versions of the Article. ... Full text Link to item Cite

Genetically Encoding Albumin Binding into Chemotherapeutic-loaded Polypeptide Nanoparticles Enhances Their Antitumor Efficacy.

Journal Article Nano letters · December 2018 We report the development of drug-encapsulating nanoparticles that bind endogenous albumin upon intravenous injection and evaluate their in vivo performance in a murine as well as canine animal model. The gene encoding a protein-G derived albumin binding d ... Full text Cite

Advances in Understanding Stimulus-Responsive Phase Behavior of Intrinsically Disordered Protein Polymers.

Journal Article Journal of molecular biology · November 2018 Proteins and synthetic polymers can undergo phase transitions in response to changes to intensive solution parameters such as temperature, proton chemical potentials (pH), and hydrostatic pressure. For proteins and protein-based polymers, the information r ... Full text Cite

Enzymatic Synthesis of Nucleobase-Modified Single-Stranded DNA Offers Tunable Resistance to Nuclease Degradation.

Journal Article Biomacromolecules · August 2018 We synthesized long, nucleobase-modified, single-stranded DNA (ssDNA) using terminal deoxynucleotidyl transferase (TdT) enzymatic polymerization. Specifically, we investigated the effect of unnatural nucleobase size and incorporation density on ssDNA resis ... Full text Cite

Sequence Directionality Dramatically Affects LCST Behavior of Elastin-Like Polypeptides.

Journal Article Biomacromolecules · July 2018 Elastin-like polypeptides (ELP) exhibit an inverse temperature transition or lower critical solution temperature (LCST) transition phase behavior in aqueous solutions. In this paper, the thermal responsive properties of the canonical ELP, poly(VPGVG), and ... Full text Cite

Genetically encoded lipid-polypeptide hybrid biomaterials that exhibit temperature-triggered hierarchical self-assembly.

Journal Article Nature chemistry · May 2018 Post-translational modification of proteins is a strategy widely used in biological systems. It expands the diversity of the proteome and allows for tailoring of both the function and localization of proteins within cells as well as the material properties ... Full text Cite

Fusion of fibroblast growth factor 21 to a thermally responsive biopolymer forms an injectable depot with sustained anti-diabetic action.

Journal Article Journal of controlled release : official journal of the Controlled Release Society · May 2018 Fibroblast growth factor 21 (FGF21) is under investigation as a type 2 diabetes protein drug, but its efficacy is impeded by rapid in vivo clearance and by costly production methods. To improve the protein's therapeutic utility, we recombinantly expressed ... Full text Cite

Convergence of Artificial Protein Polymers and Intrinsically Disordered Proteins.

Journal Article Biochemistry · May 2018 A flurry of research in recent years has revealed the molecular origins of many membraneless organelles to be the liquid phase separation of intrinsically disordered proteins (IDPs). Consequently, protein disorder has emerged as an important driver of intr ... Full text Cite

Functional Modification of Silica through Enhanced Adsorption of Elastin-Like Polypeptide Block Copolymers.

Journal Article Biomacromolecules · February 2018 A powerful tool for controlling interfacial properties and molecular architecture relies on the tailored adsorption of stimuli-responsive block copolymers onto surfaces. Here, we use computational and experimental approaches to investigate the adsorption b ... Full text Cite

Photo-Crosslinkable Unnatural Amino Acids Enable Facile Synthesis of Thermoresponsive Nano- to Microgels of Intrinsically Disordered Polypeptides.

Journal Article Advanced materials (Deerfield Beach, Fla.) · February 2018 Hydrogel particles are versatile materials that provide exquisite, tunable control over the sequestration and delivery of materials in pharmaceutics, tissue engineering, and photonics. The favorable properties of hydrogel particles depend largely on their ... Full text Cite

Nanoparticle formulation improves doxorubicin efficacy by enhancing host antitumor immunity.

Journal Article J Control Release · January 10, 2018 Strategies that enhance the host antitumor immune response promise to revolutionize cancer therapy. Optimally mobilizing the immune system will likely require a multi-pronged approach to overcome the resistance developed by tumors to therapy. Recently, it ... Full text Link to item Cite

Recombinant Synthesis of Hybrid Lipid-Peptide Polymer Fusions that Self-Assemble and Encapsulate Hydrophobic Drugs.

Journal Article Angewandte Chemie (International ed. in English) · November 2017 Inspired by biohybrid molecules that are synthesized in Nature through post-translational modification (PTM), we have exploited a eukaryotic PTM to recombinantly synthesize lipid-polypeptide hybrid materials. By co-expressing yeast N-myristoyltransferase w ... Full text Cite

The Weak Link: Optimization of the Ligand-Nanoparticle Interface To Enhance Cancer Cell Targeting by Polymer Micelles.

Journal Article Nano letters · October 2017 Many promising targeting ligands are hydrophobic peptides, and these ligands often show limited accessibility to receptors, resulting in suboptimal targeting. A systematic study to elucidate the rules for the design of linkers that optimize their presentat ... Full text Cite

Niclosamide-conjugated polypeptide nanoparticles inhibit Wnt signaling and colon cancer growth.

Journal Article Nanoscale · August 31, 2017 Abnormal Wnt activity is a major mechanism responsible for many diseases, including cancer. Previously, we reported that the anthelmintic drug Niclosamide (NIC) inhibits Wnt/β-catenin signaling and suppresses colon cancer cell growth. Although the pharmaco ... Full text Link to item Cite

A quantitative study of the intracellular fate of pH-responsive doxorubicin-polypeptide nanoparticles.

Journal Article J Control Release · August 28, 2017 Nanoscale carriers with an acid-labile linker between the carrier and drug are commonly used for drug delivery. However, their efficacy is potentially limited by inefficient linker cleavage, and lysosomal entrapment of drugs. To address these critical issu ... Full text Link to item Cite

Inkjet-printed point-of-care immunoassay on a nanoscale polymer brush enables subpicomolar detection of analytes in blood.

Journal Article Proc Natl Acad Sci U S A · August 22, 2017 Featured Publication The ELISA is the mainstay for sensitive and quantitative detection of protein analytes. Despite its utility, ELISA is time-consuming, resource-intensive, and infrastructure-dependent, limiting its availability in resource-limited regions. Here, we describe ... Full text Link to item Cite

Micellar Self-Assembly of Recombinant Resilin-/Elastin-Like Block Copolypeptides.

Journal Article Biomacromolecules · August 2017 Reported here is the synthesis of perfectly sequence defined, monodisperse diblock copolypeptides of hydrophilic elastin-like and hydrophobic resilin-like polypeptide blocks and characterization of their self-assembly as a function of structural parameters ... Full text Cite

From Composition to Cure: A Systems Engineering Approach to Anticancer Drug Carriers.

Journal Article Angewandte Chemie (International ed. in English) · June 2017 The molecular complexity and heterogeneity of cancer has led to a persistent, and as yet unsolved, challenge to develop cures for this disease. The pharmaceutical industry focuses the bulk of its efforts on the development of new drugs, but an alternative ... Full text Cite

High-Molecular-Weight Polynucleotides by Transferase-Catalyzed Living Chain-Growth Polycondensation.

Journal Article Angewandte Chemie (International ed. in English) · June 2017 We present terminal deoxynucleotidyl transferase-catalyzed enzymatic polymerization (TcEP) for the template-free synthesis of high-molecular-weight, single-stranded DNA (ssDNA) and demonstrate that it proceeds by a living chain-growth polycondensation mech ... Full text Cite

Self-assembled hybrid elastin-like polypeptide/silica nanoparticles enable triggered drug release.

Journal Article Nanoscale · May 2017 The discovery of biomimetic polypeptides that enable the biomineralization of synthetic and biosynthetic materials has resulted in the development of hybrid materials that incorporate inorganic components for potential application in drug delivery, enzyme ... Full text Cite

Encapsulating a Hydrophilic Chemotherapeutic into Rod-like Nanoparticles of a Genetically Encoded Asymmetric Triblock Polypeptide Improves its Efficacy.

Journal Article Adv Funct Mater · March 24, 2017 Encapsulating hydrophilic chemotherapeutics into the core of polymeric nanoparticles can improve their therapeutic efficacy by increasing their plasma half-life, tumor accumulation and intracellular uptake, and by protecting them from premature degradation ... Full text Link to item Cite

Cargo self-assembly rescues affinity of cell-penetrating peptides to lipid membranes

Journal Article Scientific Reports · March 6, 2017 Although cationic cell-penetrating peptides (CPPs) are able to bind to cell membranes, thus promoting cell internalization by active pathways, attachment of cargo molecules to CPPs invariably reduces their cellular uptake. We show here that CPP binding to ... Full text Cite

Site-Specific and Stoichiometric Stealth Polymer Conjugates of Therapeutic Peptides and Proteins.

Journal Article Bioconjugate chemistry · March 2017 As potent and selective therapeutic agents, peptides and proteins are an important class of drugs, but they typically have suboptimal pharmacokinetic profiles. One approach to solve this problem is their conjugation with "stealth" polymers. Conventional me ... Full text Cite

Characterisation of hydration and nanophase separation during the temperature response in hydrophobic/hydrophilic elastin-like polypeptide (ELP) diblock copolymers.

Journal Article Soft matter · March 2017 To understand the complex nanoscale dehydration process during the lower critical solution temperature (LCST) based inverse phase transition of a class of thermoresponsive biopolymers, diblock elastin-like polypeptides (ELPs) were investigated by spin prob ... Full text Cite

Quantitative Mapping of the Spatial Distribution of Nanoparticles in Endo-Lysosomes by Local pH.

Journal Article Nano letters · February 2017 Understanding the intracellular distribution and trafficking of nanoparticle drug carriers is necessary to elucidate their mechanisms of drug delivery and is helpful in the rational design of novel nanoparticle drug delivery systems. The traditional immuno ... Full text Cite

Poly(oligo(ethylene glycol) methyl ether methacrylate) Brushes on High-κ Metal Oxide Dielectric Surfaces for Bioelectrical Environments.

Journal Article ACS applied materials & interfaces · February 2017 Advances in electronics and life sciences have generated interest in "lab-on-a-chip" systems utilizing complementary metal oxide semiconductor (CMOS) circuitry for low-power, portable, and cost-effective biosensing platforms. Here, we present a simple and ... Full text Cite

Phase Behavior and Self-Assembly of Perfectly Sequence-Defined and Monodisperse Multiblock Copolypeptides.

Journal Article Biomacromolecules · February 2017 This paper investigates how the properties of multiblock copolypeptides can be tuned by their block architecture, defined by the size and distribution of blocks along the polymer chain. These parameters were explored by the precise, genetically encoded syn ... Full text Cite

Cell-Based Biohybrid Drug Delivery Systems: The Best of the Synthetic and Natural Worlds.

Journal Article Macromolecular bioscience · January 2017 The goal of drug delivery is to deliver therapeutics to the site of disease while reducing unwanted side effects. In recent years, a diverse variety of synthetic nano and microparticles have been developed as drug delivery systems. The success of these sys ... Full text Cite

Strong, Tough, Stretchable, and Self-Adhesive Hydrogels from Intrinsically Unstructured Proteins

Journal Article Advanced Materials · 2017 An experiment has demonstrated that genetically engineered unstructured proteins with covalent and reversible crosslinking (due to metal coordination and hydrophobic interactions) yield hydrogels with extremely high strength, toughness, stretchability, and ... Full text Cite

Programming molecular self-assembly of intrinsically disordered proteins containing sequences of low complexity

Journal Article Nature Chemistry · 2017 A programmable model of membraneless organelles comprised of intrinsically disordered proteins (IDPs) containing sequences of low complexity has now been developed. The rules governing the assembly of archetypal IDPs into biologically inspired mixed, layer ... Full text Cite

One-week glucose control via zero-order release kinetics from an injectable depot of glucagon-like peptide-1 fused to a thermosensitive biopolymer.

Journal Article Nat Biomed Eng · 2017 Featured Publication Stimulation of the glucagon-like peptide-1 (GLP1) receptor is a useful treatment strategy for type 2 diabetes because of pleiotropic effects, including the regulation of islet hormones and the induction of satiety. However, the native ligand for the GLP1 r ... Full text Link to item Cite

2.5 Elastin-like polypeptides

Chapter · January 1, 2017 Elastin-like polypeptides are a family of stimuli-responsive biopolymers that have been extensively studied for biomedical applications. Derived from tropoelastin, they mimic many of elastin’s remarkable material properties, yet can be designed with a mole ... Full text Cite

Silver nanoparticle toxicity is related to coating materials and disruption of sodium concentration regulation.

Journal Article Nanotoxicology · November 2016 Silver nanoparticles (AgNPs) have been increasingly commercialized and their release into the environment is imminent. Toxicity of AgNP has been studied with a wide spectrum of organisms, yet the mechanism of toxicity remains largely unknown. This study sy ... Full text Open Access Cite

Magnetophoretic transistors in a tri-axial magnetic field.

Journal Article Lab Chip · October 18, 2016 The ability to direct and sort individual biological and non-biological particles into spatially addressable locations is fundamentally important to the emerging field of single cell biology. Towards this goal, we demonstrate a new class of magnetophoretic ... Full text Link to item Cite

Controlled release of biologics for the treatment of type 2 diabetes.

Journal Article Journal of controlled release : official journal of the Controlled Release Society · October 2016 Type 2 diabetes is a rapidly growing disease that poses a significant burden to the United States healthcare system. Despite the many available treatments for the disease, close to half of diagnosed type 2 diabetes cases are not properly managed, largely d ... Full text Cite

Crystallization kinetics of binary colloidal monolayers.

Journal Article Soft matter · October 2016 Experiments and simulations are used to study the kinetics of crystal growth in a mixture of magnetic and nonmagnetic particles suspended in ferrofluid. The growth process is quantified using both a bond order parameter and a mean domain size parameter. Th ... Full text Cite

Developing Precisely Defined Drug-Loaded Nanoparticles by Ring-Opening Polymerization of a Paclitaxel Prodrug.

Journal Article Advanced healthcare materials · August 2016 Nanoparticles with high paclitaxel (PTX) loading and low systemic toxicity are prepared in scalable and versatile manner via one-step ring-opening polymerization of a prodrug monomer consisting of PTX that is appended to a cyclic carbonate through a hydrol ... Full text Cite

A Modular Method for the High-Yield Synthesis of Site-Specific Protein-Polymer Therapeutics.

Journal Article Angewandte Chemie (International ed. in English) · August 2016 A versatile method is described to engineer precisely defined protein/peptide-polymer therapeutics by a modular approach that consists of three steps: 1) fusion of a protein/peptide of interest with an elastin-like polypeptide that enables facile purificat ... Full text Cite

Magnetophoretic Conductors and Diodes in a 3D Magnetic Field.

Journal Article Adv Funct Mater · June 14, 2016 We demonstrate magnetophoretic conductor tracks that can transport single magnetized beads and magnetically labeled single cells in a 3-dimensional time-varying magnetic field. The vertical field bias, in addition to the in-plane rotating field, has the ad ... Full text Link to item Cite

Creating cellular patterns using genetically engineered, gold- and cell-binding polypeptides.

Journal Article Biointerphases · June 2016 Patterning cells on material surfaces is an important tool for the study of fundamental cell biology, tissue engineering, and cell-based bioassays. Here, the authors report a simple approach to pattern cells on gold patterned silicon substrates with high p ... Full text Cite

Injectable polypeptide micelles that form radiation crosslinked hydrogels in situ for intratumoral radiotherapy.

Journal Article J Control Release · April 28, 2016 Intratumoral radiation therapy - 'brachytherapy' - is a highly effective treatment for solid tumors, particularly prostate cancer. Current titanium seed implants, however, are permanent and are limited in clinical application to indolent malignancies of lo ... Full text Link to item Cite

Combinatorial codon scrambling enables scalable gene synthesis and amplification of repetitive proteins.

Journal Article Nature materials · April 2016 Featured Publication Most genes are synthesized using seamless assembly methods that rely on the polymerase chain reaction (PCR). However, PCR of genes encoding repetitive proteins either fails or generates nonspecific products. Motivated by the need to efficiently generate ne ... Full text Cite

Maleimide-Functionalized Poly(2-Oxazoline)s and Their Conjugation to Elastin-Like Polypeptides.

Journal Article Macromolecular bioscience · March 2016 The design of drug delivery systems capable of efficiently delivering poorly soluble drugs to target sites still remains a major challenge. Such materials require several different functionalities; typically, these materials should be biodegradable and non ... Full text Cite

Spatiotemporally photoradiation-controlled intratumoral depot for combination of brachytherapy and photodynamic therapy for solid tumor.

Journal Article Biomaterials · February 2016 In an attempt to spatiotemporally control both tumor retention and the coverage of anticancer agents, we developed a photoradiation-controlled intratumoral depot (PRCITD) driven by convection enhanced delivery (CED). This intratumoral depot consists of rec ... Full text Link to item Cite

Elastin-Like Polypeptides: Bio-Inspired Smart Polymers for Protein Purification, Drug Delivery and Tissue Engineering

Chapter · January 1, 2016 Elastin-Like Polypeptides (ELPs) have several interesting properties that are relevant to their use in biotechnology and medicine. ELPs have several interesting properties that are relevant to their use in biotechnology and medicine. First, ELPs exhibit re ... Full text Cite

A brush-polymer conjugate of exendin-4 reduces blood glucose for up to five days and eliminates poly(ethylene glycol) antigenicity.

Journal Article Nat Biomed Eng · 2016 Featured Publication The delivery of therapeutic peptides and proteins is often challenged by a short half-life, and thus the need for frequent injections that limit efficacy, reduce patient compliance and increase treatment cost. Here, we demonstrate that a single subcutaneou ... Full text Link to item Cite

Site-Specific Zwitterionic Polymer Conjugates of a Protein Have Long Plasma Circulation.

Journal Article Chembiochem : a European journal of chemical biology · November 2015 Many proteins suffer from suboptimal pharmacokinetics (PK) that limit their utility as drugs. The efficient synthesis of polymer conjugates of protein drugs with tunable PK to optimize their in vivo efficacy is hence critical. We report here the first stud ... Full text Cite

Sequence heuristics to encode phase behaviour in intrinsically disordered protein polymers.

Journal Article Nature materials · November 2015 Featured Publication Proteins and synthetic polymers that undergo aqueous phase transitions mediate self-assembly in nature and in man-made material systems. Yet little is known about how the phase behaviour of a protein is encoded in its amino acid sequence. Here, by synthesi ... Full text Cite

Prediction of solvent-induced morphological changes of polyelectrolyte diblock copolymer micelles.

Journal Article Soft matter · November 2015 Self-assembly processes of polyelectrolyte block copolymers are ubiquitous in industrial and biological processes; understanding their physical properties can also provide insights into the design of polyelectrolyte materials with novel and tailored proper ... Full text Cite

Characterizing the Switching Thresholds of Magnetophoretic Transistors.

Journal Article Adv Mater · October 28, 2015 The switching thresholds of magnetophoretic transistors for sorting cells in microfluidic environments are characterized. The transistor operating conditions require short 20-30 mA pulses of electrical current. By demonstrating both attractive and repulsiv ... Full text Open Access Link to item Cite

Protein-polymer conjugation-moving beyond PEGylation.

Journal Article Current opinion in chemical biology · October 2015 In this review, we summarize-from a materials science perspective-the current state of the field of polymer conjugates of peptide and protein drugs, with a focus on polymers that have been developed as alternatives to the current gold standard, poly(ethyle ... Full text Cite

Structural Evolution of a Stimulus-Responsive Diblock Polypeptide Micelle by Temperature Tunable Compaction of its Core

Journal Article Macromolecules · September 22, 2015 With a perfectly defined primary structure, both in terms of monomer sequence and chain length, recombinant polypeptides obtained by protein engineering techniques allow the investigation of structure-property relationships at a level of detail that is dif ... Full text Cite

Elastin-like polypeptides as models of intrinsically disordered proteins.

Journal Article FEBS letters · September 2015 Elastin-like polypeptides (ELPs) are a class of stimuli-responsive biopolymers inspired by the intrinsically disordered domains of tropoelastin that are composed of repeats of the VPGXG pentapeptide motif, where X is a "guest residue". They undergo a rever ... Full text Cite

A paclitaxel-loaded recombinant polypeptide nanoparticle outperforms Abraxane in multiple murine cancer models.

Journal Article Nat Commun · August 4, 2015 Featured Publication Packaging clinically relevant hydrophobic drugs into a self-assembled nanoparticle can improve their aqueous solubility, plasma half-life, tumour-specific uptake and therapeutic potential. To this end, here we conjugated paclitaxel (PTX) to recombinant chi ... Full text Link to item Cite

Bio-inspired synthesis of hybrid silica nanoparticles templated from elastin-like polypeptide micelles.

Journal Article Nanoscale · July 2015 The programmed self-assembly of block copolymers into higher order nanoscale structures offers many attractive attributes for the development of new nanomaterials for numerous applications including drug delivery and biosensing. The incorporation of biomim ... Full text Cite

Doxorubicin-conjugated polypeptide nanoparticles inhibit metastasis in two murine models of carcinoma.

Journal Article J Control Release · June 28, 2015 Drug delivery vehicles are often assessed for their ability to control primary tumor growth, but the outcome of cancer treatment depends on controlling or inhibiting metastasis. Therefore, we studied the efficacy of our genetically encoded polypeptide nano ... Full text Link to item Cite

Bioinspired reversibly cross-linked hydrogels comprising polypeptide micelles exhibit enhanced mechanical properties

Journal Article Advanced Functional Materials · June 1, 2015 Noncovalently cross-linked networks are attractive hydrogel platforms because of their facile fabrication, dynamic behavior, and biocompatibility. The majority of noncovalently cross-linked hydrogels, however, exhibits poor mechanical properties, which sig ... Full text Cite

Sustained intra-articular delivery of IL-1RA from a thermally-responsive elastin-like polypeptide as a therapy for post-traumatic arthritis.

Journal Article Eur Cell Mater · January 31, 2015 Post-traumatic arthritis (PTA) is a rapidly progressive form of arthritis that develops due to joint injury, including articular fracture. Current treatments are limited to surgical restoration and stabilization of the joint; however, evidence suggests tha ... Full text Link to item Cite

A noncanonical function of sortase enables site-specific conjugation of small molecules to lysine residues in proteins.

Journal Article Angewandte Chemie (International ed. in English) · January 2015 We provide the first demonstration that isopeptide ligation, a noncanonical activity of the enzyme sortase A, can be used to modify recombinant proteins. This reaction was used in vitro to conjugate small molecules to a peptide, an engineered targeting pro ... Full text Cite

Ring-opening polymerization of prodrugs: a versatile approach to prepare well-defined drug-loaded nanoparticles.

Journal Article Angewandte Chemie (International ed. in English) · January 2015 The synthesis of polymer-drug conjugates from prodrug monomers consisting of a cyclic polymerizable group that is appended to a drug through a cleavable linker is achieved by organocatalyzed ring-opening polymerization. The monomers polymerize into well-de ... Full text Cite

Elastin-like Polypeptide Diblock Copolymers Self-Assemble into Weak Micelles

Journal Article Macromolecules · 2015 The self-assembly of synthetic diblock copolymers has been extensively studied experimentally and theoretically. In contrast, self-assembly of polypeptide diblock copolymers has so far been mostly studied experimentally. We discovered that the theory devel ... Full text Cite

Noncanonical self-assembly of highly asymmetric genetically encoded polypeptide amphiphiles into cylindrical micelles.

Journal Article Nano letters · November 2014 Elastin-like polypeptides (ELPs) are a class of biopolymers consisting of the pentameric repeat (VPGαG)n based on the sequence of mammalian tropoelastin that display a thermally induced soluble-to-insoluble phase transition in aqueous solution. We have dis ... Full text Cite

Molecular description of the LCST behavior of an elastin-like polypeptide.

Journal Article Biomacromolecules · October 2014 Elastin-like polypeptides (ELPs) with the repeat sequence of VPGVG are widely used as a model system for investigation of lower critical solution temperature (LCST) transition behavior. In this paper, the effect of temperature on the structure, dynamics an ... Full text Cite

Nanoparticle-Film Plasmon Ruler Interrogated with Transmission Visible Spectroscopy.

Journal Article ACS photonics · October 2014 The widespread use of plasmonic nanorulers (PNRs) in sensing platforms has been plagued by technical challenges associated with the development of methods to fabricate precisely controlled nanostructures with high yield and characterize them with high thro ... Full text Cite

Abstract 4481: Genetically encoded chimeric polypeptide nanoparticles for gemcitabine delivery to solid tumors

Conference Cancer Research · October 1, 2014 AbstractGemcitabine (2′,2′-difluorodeoxycytidine) (dFdC) is a chemotherapeutic drug indicated for the treatment of pancreatic, bladder, NSCLC, breast and ovarian cancers. The use of gemcitabine for the treat ... Full text Cite

Abstract 4583: In situ photocontrolled intratumoral depot for combined photodynamic therapy and brachytherapy for solid tumor

Conference Cancer Research · October 1, 2014 AbstractIntratumoral (i.t.) drug delivery can circumvent the transport barriers_high intratumoral fluid pressure and irregular vascularization_of solid tumors that limit the effectiveness of systemically del ... Full text Cite

Co-opting biology to deliver drugs.

Journal Article Biotechnology and bioengineering · September 2014 The goal of drug delivery is to improve the safety and therapeutic efficacy of drugs. This review focuses on delivery platforms that are either derived from endogenous pathways, long-circulating biomolecules and cells or that piggyback onto long-circulatin ... Full text Cite

Applications of elastin-like polypeptides in drug delivery.

Journal Article Journal of controlled release : official journal of the Controlled Release Society · September 2014 Elastin-like polypeptides (ELPs) are biopolymers inspired by human elastin. Their lower critical solution temperature phase transition behavior and biocompatibility make them useful materials for stimulus-responsive applications in biological environments. ... Full text Cite

Surface initiated polymerization and its applications in medicine

Conference ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · August 10, 2014 Link to item Cite

Simple assay for proteases based on aggregation of stimulus-responsive polypeptides.

Journal Article Analytical chemistry · June 2014 Unregulated changes in protease activity are linked to many diseases including cancer. Fast, accurate, and low-cost assays for detection of these changes are being explored for early diagnosis and monitoring of these diseases and can also be used as platfo ... Full text Cite

Non-chromatographic purification of recombinant elastin-like polypeptides and their fusions with peptides and proteins from Escherichia coli.

Journal Article Journal of visualized experiments : JoVE · June 2014 Elastin-like polypeptides are repetitive biopolymers that exhibit a lower critical solution temperature phase transition behavior, existing as soluble unimers below a characteristic transition temperature and aggregating into micron-scale coacervates above ... Full text Cite

Rational design of "heat seeking" drug loaded polypeptide nanoparticles that thermally target solid tumors.

Journal Article Nano Lett · May 14, 2014 This paper demonstrates the first example of targeting a solid tumor that is externally heated to 42 °C by "heat seeking" drug-loaded polypeptide nanoparticles. These nanoparticles consist of a thermally responsive elastin-like polypeptide (ELP) conjugated ... Full text Link to item Cite

Enzymatic polymerization of high molecular weight DNA amphiphiles that self-assemble into star-like micelles.

Journal Article Advanced materials (Deerfield Beach, Fla.) · May 2014 High molecular weight ssDNA amphiphiles are synthesized by enzymatic polymerization. These highly asymmetric diblock DNA copolymers self-assemble into "hairy", star-like micelles, shown in the AFM image and the DPD snapshot. ... Full text Cite

Genetically encoded polypeptide nanoparticles for delivery of drugs

Conference ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · March 16, 2014 Link to item Cite

"Smart" DNA interfaces.

Journal Article Chemical Society reviews · March 2014 This review focuses on surface-grafted DNA, and its use as a molecular building block that exploits its unique properties as a directional (poly)anion that exhibits molecular recognition. The selected examples highlight innovative applications of DNA at su ... Full text Cite

Genetically encoded smart peptide polymers for biomedicine

Journal Article MRS Bulletin · January 27, 2014 Drug delivery systems are becoming increasingly sophisticated, with the ability to target and penetrate specific tissues and release drugs based upon the local environment. While these advanced systems often offer advantages over their less sophisticated c ... Full text Cite

Growing polymers from peptides and proteins: A biomedical perspective

Journal Article Polymer Chemistry · January 21, 2014 This review covers the development of the in situ growth of polymers from biomolecules, also termed the "grafting from" conjugation methodology. We trace the evolution of this field of research, with an emphasis on recently developed methods to synthesize ... Full text Cite

Controlled apoptosis by a thermally toggled nanoscale amplifier of cellular uptake.

Journal Article Nano letters · January 2014 Internalization into cancer cells is a significant challenge in the delivery of many anticancer therapeutics. Drug carriers can address this challenge by facilitating cellular uptake of cytotoxic cargo in the tumor, while preventing cellular uptake in heal ... Full text Cite

Non-chromatographic purification of recombinant elastin-like polypeptides and their fusions with peptides and proteins from Escherichia coli.

Journal Article Journal of visualized experiments : JoVE · January 1, 2014 Elastin-like polypeptides are repetitive biopolymers that exhibit a lower critical solution temperature phase transition behavior, existing as soluble unimers below a characteristic transition temperature and aggregating into micron-scale coacervates above ... Cite

The language of protein polymers

Conference ACS Symposium Series · January 1, 2014 Proteins are heteropolymers of one or more amino acid residues arranged in a molecularly defined fashion. The precise control of amino acid sequence in protein biosynthesis programs the folding of these heteropolymers into diverse three-dimensional structu ... Full text Cite

Encapsulation of stimuli-responsive fusion proteins in silica: Thermally responsive metal ion-sensitive hybrid membranes

Journal Article Materials Research Society Symposium Proceedings · December 1, 2013 In this study, we demonstrate the fabrication of hybrid membranes that exhibit discrete and reversible changes in permeability in response to changes in calcium ion (Ca2+) concentration and temperature. Fusion proteins comprising calmodulin (CAM) and elast ... Full text Cite

A depot-forming glucagon-like peptide-1 fusion protein reduces blood glucose for five days with a single injection.

Journal Article Journal of controlled release : official journal of the Controlled Release Society · November 2013 Peptide drugs are an exciting class of pharmaceuticals for the treatment of a variety of diseases; however, their short half-life dictates multiple and frequent injections causing undesirable side effects. Herein, we describe a novel peptide delivery syste ... Full text Cite

A genetically engineered thermally responsive sustained release curcumin depot to treat neuroinflammation.

Journal Article Journal of controlled release : official journal of the Controlled Release Society · October 2013 Radiculopathy, a painful neuroinflammation that can accompany intervertebral disc herniation, is associated with locally increased levels of the pro-inflammatory cytokine tumor necrosis factor alpha (TNFα). Systemic administration of TNF antagonists for ra ... Full text Open Access Cite

Genetically engineered polypeptide conjugates and fusions for drug delivery

Conference ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · September 8, 2013 Link to item Cite

Enzyme catalyzed polymerization of DNA amphiphiles that self-assemble into star-like micelles

Conference ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · September 8, 2013 Link to item Cite

Syntax of "smart" peptide polymers governs their function

Conference ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · September 8, 2013 Link to item Cite

Elastin-based amphiphilic copolymers as precision building blocks for controlled self-assembly

Conference ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · September 8, 2013 Link to item Cite

Actively targeting solid tumours with thermoresponsive drug delivery systems that respond to mild hyperthermia.

Journal Article Int J Hyperthermia · September 2013 A diverse range of drug delivery vehicles have been developed to specifically target chemotherapeutics to solid tumours while avoiding systemic dose-limiting toxicity. Many of these active targeting strategies display limited efficacy because they rely on ... Full text Link to item Cite

Amplified fluorescence detection of DNA and RNA hybridization by surface initiated enzymatic polymerization (SIEP)

Journal Article Technical Proceedings of the 2013 NSTI Nanotechnology Conference and Expo, NSTI-Nanotech 2013 · August 9, 2013 Detection of nucleic acid on-chip has been of great interest due to its potential as research tools and for diagnostic applications. We present a new on-chip, isothermal signal amplification technique for the direct detection of unmodified DNA and RNA on m ... Cite

Sortase-catalyzed initiator attachment enables high yield growth of a stealth polymer from the C terminus of a protein.

Journal Article Macromolecular rapid communications · August 2013 Conventional methods for synthesizing protein/peptide-polymer conjugates, as a means to improve the pharmacological properties of therapeutic biomolecules, typically have drawbacks including low yield, non-trivial separation of conjugates from reactants, a ... Full text Cite

A unified model for de novo design of elastin-like polypeptides with tunable inverse transition temperatures.

Journal Article Biomacromolecules · August 2013 Elastin-like polypeptides (ELPs) are stimulus-responsive peptide polymers that exhibit inverse temperature phase transition behavior, causing an ELP to aggregate above its inverse transition temperature (T(t)). Although this property has been exploited in ... Full text Cite

Spectroscopic study of a DNA brush synthesized in situ by surface initiated enzymatic polymerization.

Journal Article The journal of physical chemistry. B · August 2013 We used a combination of synchrotron-based X-ray photoelectron spectroscopy (XPS) and angle-resolved near-edge X-ray absorption fine structure (NEXAFS) spectroscopy to study the chemical integrity, purity, and possible internal alignment of single-strand ( ... Full text Cite

Interactions of elastin-like polypeptides with model membranes on GUVs

Conference EUROPEAN BIOPHYSICS JOURNAL WITH BIOPHYSICS LETTERS · July 1, 2013 Link to item Cite

Calcium binding peptide motifs from calmodulin confer divalent ion selectivity to elastin-like polypeptides.

Journal Article Biomacromolecules · July 2013 Calcium-sensitive elastin-like polypeptides (CELPs) were synthesized by periodically interspersing a calcium-binding peptide sequence from calmodulin within an elastin-like polypeptide (ELP) with the goal of creating thermal and calcium responsive peptide ... Full text Cite

Hydration layer coupling and cooperativity in phase behavior of stimulus responsive peptide polymers.

Journal Article Journal of the American Chemical Society · July 2013 It is shown that hydrophilic (backbone) and hydrophobic (side chain) hydration layers of elastin-like polypeptides (ELPs), a class of stimulus responsive peptide polymers that exhibit lower critical solution temperature (LCST) phase transition behavior, ca ... Full text Cite

Cylindrical polymer brushes with elastin-like polypeptide side chains

Journal Article Macromolecules · June 25, 2013 Monodisperse high molar mass elastin-like polypeptide macromonomers comprising 20 pentasequences (M = 8332 g/mol) were radically polymerized to high degrees of polymerization Pw = 590. Polymerization was conducted in water well above the lower phase transi ... Full text Cite

Predicting transition temperatures of elastin-like polypeptide fusion proteins.

Journal Article Biomacromolecules · May 2013 Elastin-like polypeptides (ELPs) are thermally sensitive peptide polymers that undergo thermally triggered phase separation and this behavior is imparted to soluble proteins when they are fused to an ELP. The transition temperature of the ELP fusion protei ... Full text Cite

Abstract 5615: Evaluation of the antitumoral efficacy and toxicity of injectable, polymeric radionuclide seeds in a noninvasive preclinical prostate tumor model.

Conference Cancer Research · April 15, 2013 AbstractBrachytherapy continues to be one of the predominant radiotherapy modalities for the treatment of prostate cancer. Depending on the stage of the cancer, it is employed either as a stand-alone treatme ... Full text Cite

Abstract 4509: Genetically encoded chimeric polypeptide nanoparticles for paclitaxel delivery to triple negative breast cancer.

Conference Cancer Research · April 15, 2013 AbstractTriple negative breast cancer (TNBC) represents an important clinical challenge, because TNBC, like other breast cancer subtypes is highly metastatic, but TNBC displays a shorter median time to relap ... Full text Cite

Abstract 4341: A novel injectable polymer liquid that self-assembles into radioactive “seeds” for brachytherapy.

Conference Cancer Research · April 15, 2013 AbstractBrachytherapy seeds are made by sealing radionuclides in metal or other non-degradable material (resin or glass) and surgically implanted into the tumor tissue. Brachytherapy has shown some efficacy ... Full text Cite

Delivery of paclitaxel with elastin-like polypeptides

Conference ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · April 7, 2013 Link to item Cite

Injectable protease-operated depots of glucagon-like peptide-1 provide extended and tunable glucose control.

Journal Article Proceedings of the National Academy of Sciences of the United States of America · February 2013 Peptide drugs are an exciting class of pharmaceuticals increasingly used for the treatment of a variety of diseases; however, their main drawback is a short half-life, which dictates multiple and frequent injections and an undesirable "peak-and-valley" pha ... Full text Cite

Self-assembly of thermally responsive nanoparticles of a genetically encoded peptide polymer by drug conjugation.

Journal Article Angewandte Chemie (International ed. in English) · February 2013 Full text Cite

Surface Patterning

Chapter · January 1, 2013 Full text Cite

Harnessing the power of cell-penetrating peptides: activatable carriers for targeting systemic delivery of cancer therapeutics and imaging agents.

Journal Article Wiley interdisciplinary reviews. Nanomedicine and nanobiotechnology · January 2013 Targeted delivery of cancer therapeutics and imaging agents aims to enhance the accumulation of these molecules in a solid tumor while avoiding uptake in healthy tissues. Tumor-specific accumulation has been pursued with passive targeting by the enhanced p ... Full text Cite

Effect of detergents on the thermal behavior of elastin-like polypeptides.

Journal Article Biopolymers · January 2013 Elastin-like polypeptide (ELP) fusions have been designed to allow large-scale, nonchromatographic purification of many soluble proteins by using the inverse transition cycling (ITC) method; however, the sensitivity of the aqueous lower critical solubility ... Full text Cite

Direct fluorescence detection of RNA on microarrays by surface-initiated enzymatic polymerization.

Journal Article Analytical chemistry · January 2013 We report the first demonstration of surface-initiated enzymatic polymerization (SIEP) for the direct detection of RNA in a fluorescence microarray format. This new method incorporates multiple fluorophores into an RNA strand using the two-step sequential ... Full text Cite

Plasmonic waveguide modes of film-coupled metallic nanocubes.

Journal Article Nano letters · January 2013 A metallic nanoparticle positioned over a metal film offers great advantages as a highly controllable system relevant for probing field-enhancement and other plasmonic effects. Because the size and shape of the gap between the nanoparticle and film can be ... Full text Cite

Controlled-reflectance surfaces with film-coupled colloidal nanoantennas.

Journal Article Nature · December 2012 Efficient and tunable absorption is essential for a variety of applications, such as designing controlled-emissivity surfaces for thermophotovoltaic devices, tailoring an infrared spectrum for controlled thermal dissipation and producing detector elements ... Full text Cite

Brachytherapy using injectable seeds that are self-assembled from genetically encoded polypeptides in situ.

Journal Article Cancer Res · November 15, 2012 Brachytherapy is a common clinical technique involving implantation of sealed radioactive "seeds" within a tumor to selectively irradiate the tumor mass while minimizing systemic toxicity. To mitigate the disadvantages associated with complex surgical impl ... Full text Link to item Cite

Overcoming limitations in nanoparticle drug delivery: triggered, intravascular release to improve drug penetration into tumors.

Journal Article Cancer Res · November 1, 2012 Traditionally, the goal of nanoparticle-based chemotherapy has been to decrease normal tissue toxicity by improving drug specificity to tumors. The enhanced permeability and retention effect can permit passive accumulation into tumor interstitium. However, ... Full text Link to item Cite

Plasmon ruler with angstrom length resolution.

Journal Article ACS nano · October 2012 We demonstrate a plasmon nanoruler using a coupled film nanoparticle (film-NP) format that is well-suited for investigating the sensitivity extremes of plasmonic coupling. Because it is relatively straightforward to functionalize bulk surface plasmon suppo ... Full text Cite

Uptake of silver nanoparticles and toxicity to early life stages of Japanese medaka (Oryzias latipes): effect of coating materials.

Journal Article Aquatic toxicology (Amsterdam, Netherlands) · September 2012 Silver nanoparticles (AgNPs) with antimicrobial properties are perhaps the most deployed engineered nanomaterials in consumer products. Almost all AgNPs are coated with organic materials to enhance their dispersion in water. Contributions of coatings to th ... Full text Cite

Biomolecular toolbox for the in situ synthesis of protein-polymer conjugates

Conference ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · August 19, 2012 Link to item Cite

Rheological properties of cysteine-containing elastin-like polypeptide solutions and hydrogels.

Journal Article Biomacromolecules · August 2012 The rheological properties of cysteine-containing elastin-like polypeptide (Cys-ELP) solutions and Cys-ELP hydrogels are reported. The Cys-ELP solutions exhibit a surprisingly high apparent viscosity at low shear rate. The high viscosity is attributed to t ... Full text Cite

Probing the ultimate limits of plasmonic enhancement.

Journal Article Science (New York, N.Y.) · August 2012 Metals support surface plasmons at optical wavelengths and have the ability to localize light to subwavelength regions. The field enhancements that occur in these regions set the ultimate limitations on a wide range of nonlinear and quantum optical phenome ... Full text Open Access Cite

Protein polymer hydrogels by in situ, rapid and reversible self-gelation.

Journal Article Biomaterials · July 2012 Protein-based biomaterials are an important class of materials for applications in biotechnology and medicine. The exquisite control of their composition, stereochemistry, and chain length offers unique opportunities to engineer biofunctionality, biocompat ... Full text Link to item Cite

Chemistry. Nanomaterials for drug delivery.

Journal Article Science (New York, N.Y.) · July 2012 Full text Cite

Digital switching of local arginine density in a genetically encoded self-assembled polypeptide nanoparticle controls cellular uptake.

Journal Article Nano letters · June 2012 Cell-penetrating peptides (CPPs) are a class of molecules that enable efficient internalization of a wide variety of cargo in diverse cell types, making them desirable for delivery of anticancer drugs to solid tumors. For CPPs to be useful, it is important ... Full text Cite

Doxorubicin-conjugated chimeric polypeptide nanoparticles that respond to mild hyperthermia.

Journal Article J Control Release · May 10, 2012 This paper reports the design, physicochemical characterization and in vitro cytotoxicity of a thermally responsive chimeric polypeptide (CP), derived from an elastin-like polypeptide (ELP). The CP self-assembles into ~40 nm diameter nanoparticles upon con ... Full text Link to item Cite

Unexpected multivalent display of proteins by temperature triggered self-assembly of elastin-like polypeptide block copolymers.

Journal Article Biomacromolecules · May 2012 We report herein the unexpected temperature triggered self-assembly of proteins fused to thermally responsive elastin-like polypeptides (ELPs) into spherical micelles. A set of six ELP block copolymers (ELP(BC)) differing in hydrophilic and hydrophobic blo ... Full text Cite

Probing dynamically tunable localized surface plasmon resonances of film-coupled nanoparticles by evanescent wave excitation.

Journal Article Nano letters · April 2012 The localized surface plasmon resonance (LSPR) spectrum associated with a gold nanoparticle (NP) coupled to a gold film exhibits extreme sensitivity to the nanogap region where the fields are tightly localized. The LSPR of an ensemble of film-coupled NPs c ... Full text Cite

Triple stimulus-responsive polypeptide nanoparticles that enhance intratumoral spatial distribution.

Journal Article Nano letters · April 2012 To address the limited tumor penetration of nanoparticle drug delivery vehicles, we report the first pH-responsive polypeptide micelle that dissociates at the low extracellular pH of solid tumors. This histidine-rich elastin-like polypeptide block copolyme ... Full text Cite

Genetically encoded stimulus responsive elastin-like polypeptides: Applications in drug delivery

Conference ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · March 25, 2012 Link to item Cite

Protein switches

Journal Article · January 1, 2012 Many essential cellular processes rely on naturally evolved protein switches that react in response to a particular signal, including up- and downregulation of gene expression, cell signaling processes, and allosteric enzymatic reactions. Most of these rea ... Full text Cite

Individual plasmonic nanostructures as label free biosensors

Chapter · January 1, 2012 This chapter reviews our work and that of other groups in the use of individual plasmonic nanostructures that are presented by a substrate for the labelfree detection of biomolecular binding events. This class of single particle nanosensors is based on the ... Full text Cite

Fusions of elastin-like polypeptides to pharmaceutical proteins.

Journal Article Methods in enzymology · January 2012 Elastin-like polypeptides (ELPs) are a class of stimulus-responsive biopolymers whose physicochemical properties and biocompatibility are particularly suitable for in vivo applications, such as drug delivery and tissue engineering. The lower critical solut ... Full text Cite

Field-induced nanolithography for the patterning of non-fouling polymer brushes

Conference ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · 2012 Cite

Raman antenna formed by molecule/plasmonic nanostructure hybrid system

Journal Article Optics InfoBase Conference Papers · December 1, 2011 A nano-antenna composed of a particle and a polarizable surface provides control of the spatial distribution and high enhancement of Raman scattering. This structure may serve as a stable platform for single molecule detection. © 2010 Optical Society of Am ... Cite

Field-induced nanolithography for patterning of non-fouling polymer brush surfaces.

Journal Article Small (Weinheim an der Bergstrasse, Germany) · November 2011 Full text Cite

Hyperspectral molecular imaging of multiple receptors using immunolabeled plasmonic nanoparticles.

Journal Article Journal of biomedical optics · November 2011 This work presents simultaneous imaging and detection of three different cell receptors using three types of plasmonic nanoparticles (NPs). The size, shape, and composition-dependent scattering profiles of these NPs allow for a system of multiple distinct ... Full text Cite

In vivo tumor targeting by a NGR-decorated micelle of a recombinant diblock copolypeptide.

Journal Article J Control Release · October 30, 2011 Antivascular targeting is a promising strategy for tumor therapy. This strategy has the potential to overcome many of the transport barriers associated with targeting tumor cells in solid tumors, because the tumor vasculature is directly accessible to targ ... Full text Link to item Cite

Raman antenna formed by molecule/plasmonic nanostructure hybrid system

Journal Article 2011 Conference on Lasers and Electro-Optics: Laser Science to Photonic Applications, CLEO 2011 · September 1, 2011 A nano-antenna composed of a particle and a polarizable surface provides control of the spatial distribution and high enhancement of Raman scattering. This structure may serve as a stable platform for single molecule detection. © 2011 OSA. ... Cite

In situ growth of a thermoresponsive polymer from a genetically engineered elastin-like polypeptide

Journal Article Polymer Chemistry · July 1, 2011 We report the in situ growth of a thermoresponsive dumbbell-like polymer conjugate of a genetically engineered triblock elastin-like polypeptide (tELP). Atom transfer radical polymerization (ATRP) was used to directly grow a PEG-like polymer selectively fr ... Full text Cite

Dual-order snapshot spectral imaging of plasmonic nanoparticles.

Journal Article Applied optics · July 2011 The development of truly scalable, multiplexed optical microarrays requires a detection platform capable of simultaneous detection of multiple signals in real-time. We present a technique we term dual-order snapshot spectroscopic imaging (DOSSI) and demons ... Full text Cite

Amplified on-chip fluorescence detection of DNA hybridization by surface-initiated enzymatic polymerization.

Journal Article Analytical chemistry · July 2011 We describe the incorporation of multiple fluorophores into a single stranded DNA (ssDNA) chain using terminal deoxynucleotidyl transferase (TdT), a template-independent DNA polymerase that catalyzes the sequential addition of deoxynucleotides (dNTPs) at t ... Full text Cite

Self-assembly of monodisperse oligonucleotide-elastin block copolymers into stars and compound micelles.

Journal Article Chemistry (Weinheim an der Bergstrasse, Germany) · May 2011 Full text Cite

Hyperspectral molecular imaging of multiple receptors using immunolabeled plasmonic nanoparticles

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · April 29, 2011 This work presents simultaneous imaging and detection of three types of cell receptors using three types of plasmonic nanoparticles. The size, shape, and composition-dependent scattering profiles of these particles allow for a system of multiple distinct m ... Full text Cite

Micro- and nanostructured poly[oligo(ethylene glycol)methacrylate] brushes grown from photopatterned halogen initiators by atom transfer radical polymerization.

Journal Article Biointerphases · March 2011 Photolithographic techniques have been used to fabricate polymer brush micro- and nanostructures. On exposure to UV light with a wavelength of 244 nm, halogens were selectively removed from films of chloromethylphenyltrichlorosilane and 3-(2-bromoisobutyra ... Full text Cite

A highly parallel method for synthesizing DNA repeats enables the discovery of 'smart' protein polymers.

Journal Article Nat Mater · February 2011 Featured Publication Robust high-throughput synthesis methods are needed to expand the repertoire of repetitive protein-polymers for different applications. To address this need, we developed a new method, overlap extension rolling circle amplification (OERCA), for the highly ... Full text Link to item Cite

Spatially addressable chemoselective C-terminal ligation of an intein fusion protein from a complex mixture to a hydrazine-terminated surface.

Journal Article Langmuir : the ACS journal of surfaces and colloids · February 2011 Protein immobilization on surfaces is useful in many areas of research, including biological characterization, antibody purification, and clinical diagnostics. A critical limitation in the development of protein microarrays and heterogeneous protein-based ... Full text Cite

Plasmonic flow cytometry by immunolabeled nanorods.

Journal Article Cytometry A · January 2011 Fluorescence-based flow cytometry measures multiple cellular characteristics, including levels of receptor expression, by assessing the fluorescence intensity from a population of cells whose cell surface receptors are bound by a fluorescently labeled anti ... Full text Link to item Cite

The use of micropatterning to control smooth muscle myosin heavy chain expression and limit the response to transforming growth factor β1 in vascular smooth muscle cells.

Journal Article Biomaterials · January 2011 In the healthy artery, contractile vascular smooth muscle cells (VSMCs) have an elongated shape and are highly aligned but transition to a synthetic phenotype in culture, while additionally becoming well spread and randomly organized. Thus, controlling VSM ... Full text Cite

NANOSCALE SELF-ASSEMBLY FOR DELIVERY OF THERAPEUTICS AND IMAGING AGENTS.

Journal Article Technology and innovation · January 2011 Self-assemblies are complex structures spontaneously organized from simpler subcomponents, primarily through noncovalent interactions. These structures are being exploited as delivery vehicles of therapeutic and imaging agents. They have two unique advanta ... Full text Cite

Applications of elastin-like polypeptides in tissue engineering.

Journal Article Advanced drug delivery reviews · December 2010 Elastin-like polypeptides (ELPs) have found utility in tissue engineering applications, not only because they are biocompatible, biodegradable, and non-immunogenic, but also because their amino acid sequence and molecular weight can be precisely controlled ... Full text Cite

Drug delivery to solid tumors by elastin-like polypeptides.

Journal Article Advanced drug delivery reviews · December 2010 Thermally responsive elastin-like polypeptides (ELPs) are a promising class of recombinant biopolymers for the delivery of drugs and imaging agents to solid tumors via systemic or local administration. This article reviews four applications of ELPs to drug ... Full text Cite

Gold nanoparticles on polarizable surfaces as Raman scattering antennas.

Journal Article ACS nano · November 2010 Surface plasmons supported by metal nanoparticles are perturbed by coupling to a surface that is polarizable. Coupling results in enhancement of near fields and may increase the scattering efficiency of radiative modes. In this study, we investigate the Ra ... Full text Open Access Cite

Quantitative model of the phase behavior of recombinant pH-responsive elastin-like polypeptides.

Journal Article Biomacromolecules · November 2010 Quantitative models are required to engineer biomaterials with environmentally responsive properties. With this goal in mind, we developed a model that describes the pH-dependent phase behavior of a class of stimulus responsive elastin-like polypeptides (E ... Full text Open Access Cite

Chain stiffness of elastin-like polypeptides.

Journal Article Biomacromolecules · November 2010 Full text Open Access Cite

Leveraging nanoscale plasmonic modes to achieve reproducible enhancement of light.

Journal Article Nano letters · October 2010 The strongly enhanced and localized optical fields that occur within the gaps between metallic nanostructures can be leveraged for a wide range of functionality in nanophotonic and optical metamaterial applications. Here, we introduce a means of precise co ... Full text Open Access Cite

In situ growth of a PEG-like polymer from the C terminus of an intein fusion protein improves pharmacokinetics and tumor accumulation.

Journal Article Proc Natl Acad Sci U S A · September 21, 2010 This paper reports a general in situ method to grow a polymer conjugate solely from the C terminus of a recombinant protein. GFP was fused at its C terminus with an intein; cleavage of the intein provided a unique thioester moiety at the C terminus of GFP ... Full text Link to item Cite

Elastin-like polypeptides as a purification tag for recombinant proteins.

Journal Article Current protocols in protein science · August 2010 This unit presents a recombinant protein purification method that employs an elastin-like polypeptide (ELP) as a purification tag. ELPs undergo a sharp and reversible phase transition when heated above their lower critical solution temperature. ELPs retain ... Full text Cite

Stimulus-responsive macromolecules and nanoparticles for cancer drug delivery.

Journal Article Nanomedicine (London, England) · July 2010 Nanoparticles and macromolecular carriers have been widely used to increase the efficacy of chemotherapeutics, largely through passive accumulation provided by the enhanced permeability and retention effect. Stimulus-responsive peptide and polymer vehicles ... Full text Cite

Protein patterning by UV-induced photodegradation of poly(oligo(ethylene glycol) methacrylate) brushes.

Journal Article Langmuir : the ACS journal of surfaces and colloids · June 2010 The UV photodegradation of protein-resistant poly(oligo(ethylene glycol) methacrylate) (POEGMA) bottle-brush films, grown on silicon oxide by surface-initiated atom radical transfer polymerization, was studied using X-ray photoelectron spectroscopy (XPS) a ... Full text Open Access Cite

Injectable intratumoral depot of thermally responsive polypeptide-radionuclide conjugates delays tumor progression in a mouse model.

Journal Article J Control Release · May 21, 2010 This study evaluated a biodegradable drug delivery system for local cancer radiotherapy consisting of a thermally sensitive elastin-like polypeptide (ELP) conjugated to a therapeutic radionuclide. Two ELPs (49 kDa) were synthesized using genetic engineerin ... Full text Link to item Cite

A versatile diffractive maskless lithography for single-shot and serial microfabrication.

Journal Article Optics express · May 2010 We demonstrate a diffractive maskless lithographic system that is capable of rapidly performing both serial and single-shot micropatterning. Utilizing the diffractive properties of phase holograms displayed on a spatial light modulator, arbitrary intensity ... Full text Open Access Cite

Morphing low-affinity ligands into high-avidity nanoparticles by thermally triggered self-assembly of a genetically encoded polymer.

Journal Article ACS nano · April 2010 Multivalency is the increase in avidity resulting from the simultaneous interaction of multiple ligands with multiple receptors. This phenomenon, seen in antibody-antigen and virus-cell membrane interactions, is useful in designing bioinspired materials fo ... Full text Open Access Cite

Recursive directional ligation by plasmid reconstruction allows rapid and seamless cloning of oligomeric genes.

Journal Article Biomacromolecules · April 2010 This paper reports a new strategy, recursive directional ligation by plasmid reconstruction (PRe-RDL), to rapidly clone highly repetitive polypeptides of any sequence and specified length over a large range of molecular weights. In a single cycle of PRe-RD ... Full text Open Access Cite

Intracellular uptake and associated toxicity of silver nanoparticles in Caenorhabditis elegans

Journal Article Aquatic Toxicol · 2010 Silver nanoparticles (AgNPs) are frequently used as antimicrobials. While the mechanism(s) by which AgNPs are toxic are unclear, their increasing use raises the concern that release into the environment could lead to environmental toxicity. We characterize ... Cite

Elastin-like polypeptides: biomedical applications of tunable biopolymers.

Journal Article Biopolymers · January 2010 Artificial repetitive polypeptides have grown in popularity as a bioinspired alternative to synthetic polymers. The genetically encoded synthesis, monodispersity, potential lack of toxicity, and biocompatibility are attractive features of these biopolymers ... Full text Cite

Neural network analysis identifies scaffold properties necessary for in vitro chondrogenesis in elastin-like polypeptide biopolymer scaffolds.

Journal Article Tissue engineering. Part A · January 2010 The successful design of biomaterial scaffolds for articular cartilage tissue engineering requires an understanding of the impact of combinations of material formulation parameters on diverse and competing functional outcomes of biomaterial performance. Th ... Full text Open Access Cite

Hydrogen bonding of beta-turn structure is stabilized in D(2)O.

Journal Article Journal of the American Chemical Society · October 2009 The lower critical solution temperature (LCST) of elastin-like polypeptides (ELPs) was investigated as a function of ELP chain length and guest residue chemistry. These measurements were made in both D(2)O and H(2)O. Differences in the LCST values with hea ... Full text Cite

In situ growth of a stoichiometric PEG-like conjugate at a protein's N-terminus with significantly improved pharmacokinetics.

Journal Article Proc Natl Acad Sci U S A · September 8, 2009 The challenge in the synthesis of protein-polymer conjugates for biological applications is to synthesize a stoichiometric (typically 1:1) conjugate of the protein with a monodisperse polymer, with good retention of protein activity, significantly improved ... Full text Link to item Cite

Early metabolite levels predict long-term matrix accumulation for chondrocytes in elastin-like polypeptide biopolymer scaffolds.

Journal Article Tissue engineering. Part A · August 2009 The development of cartilage tissue engineering scaffolds could greatly benefit from methods to evaluate the interactions of cells with scaffolds that are rapid, are nondestructive, and can be carried out at early culture times. Motivated by this rationale ... Full text Cite

Fusion order controls expression level and activity of elastin-like polypeptide fusion proteins.

Journal Article Protein science : a publication of the Protein Society · July 2009 We have previously developed a method to purify recombinant proteins, termed inverse transition cycling (ITC) that eliminates the need for column chromatography. ITC exploits the inverse solubility phase transition of an elastin-like polypeptide (ELP) that ... Full text Cite

In pursuit of zero: Polymer brushes that resist the adsorption of proteins

Journal Article Advanced Materials · June 19, 2009 Protein resistant or "non-fouling" surfaces are of great interest for a variety of biomedical and biotechnology applications. This article briefly reviews the development of protein resistant surfaces, followed by recent research on a new methodology to fa ... Full text Cite

Simultaneous molecular imaging of EGFR and HER2 using hyperspectral darkfield microscopy and immunotargeted nanoparticles

Journal Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE · June 12, 2009 Epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor (HER2) contribute to the regulation of cell proliferation, and when jointly over-expressed are associated with several types of cancer. The ability to monitor both receptors ... Full text Cite

Versatile synthesis and micropatterning of nonfouling polymer brushes on the wafer scale.

Journal Article Biointerphases · June 2009 In this article, the authors describe new approaches to synthesize and pattern surfaces with poly[oligo(ethylene glycol) methyl methacrylate] (POEGMA) polymer brushes synthesized by surface-initiated atom transfer radical polymerization. These patterned co ... Full text Cite

Biological applications of polymer brushes. Preface.

Journal Article Biointerphases · June 2009 Full text Cite

Rational selection of gold nanorod geometry for label-free plasmonic biosensors.

Journal Article ACS nano · April 2009 We present the development of an analytical model that can be used for the rational design of a biosensor based on shifts in the local surface plasmon resonance (LSPR) of individual gold nanoparticles. The model relates the peak wavelength of light scatter ... Full text Cite

Precision engineered control of biomolecules at interfaces by polymer brushes

Journal Article ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · March 22, 2009 Link to item Cite

Designing interfaces for optical biosensors

Journal Article Optics InfoBase Conference Papers · January 1, 2009 I will describe two interfaces for optical biosensors: (1) a label-free biosensor that exploits the local surface plasmon resonance of noble metal nanostructures; and (2) a polymer brush interface on glass that abolishes non-specific adsorption leading to ... Cite

Designing interfaces for optical biosensors

Conference Optics InfoBase Conference Papers · January 1, 2009 I will describe two interfaces for optical biosensors: (1) a label-free biosensor that exploits the local surface plasmon resonance of noble metal nanostructures; and (2) a polymer brush interface on glass that abolishes non-specific adsorption leading to ... Full text Cite

Fabrication of Elastin-Like polypeptide Nanoparticles for Drug Delivery by Electrospraying

Journal Article Biomacromolecules · January 2009 The development of environmentally responsive drug carriers requires new methods for assembling stimuli-responsive nanoparticulates. This communication describes a novel application of electrospray to construct bioresponsive peptide-based particulates, whi ... Cite

Self-assembling chimeric polypeptide–doxorubicin conjugate nanoparticles that abolish tumours after a single injection

Journal Article Nature Materials · 2009 New strategies to self-assemble biocompatible materials into nanoscale, drug-loaded packages with improved therapeutic efficacy are needed for nanomedicine. To address this need, we developed artificial recombinant chimeric polypeptides (CPs) that spontane ... Cite

Allosteric actuation of inverse phase transition of a stimulus-responsive fusion polypeptide by ligand binding.

Journal Article Journal of the American Chemical Society · December 2008 We report herein a biopolymer actuator with a modular design that allosterically transduces ligand binding into an aqueous demixing phase transition. The biopolymer actuator consists of two modular domains: a ligand binding protein domain, calmodulin (CaM) ... Full text Cite

Patterning materials with biomolecules

Journal Article 8th World Biomaterials Congress 2008 · December 1, 2008 Cite

Effects of Hofmeister Anions on the Phase Transition Temperature of Elastin-like Polypeptides

Journal Article Journal Of Physical Chemistry B · November 2008 The modulation of the lower critical solution temperature (LCST) of two elastin-like polypeptides (ELPs) was investigated in the presence of 11 sodium salts that span the Hoftneister series for anions. It was found that the hydrophobic collapse/aggregation ... Cite

Temperature sensitive peptides: engineering hyperthermia-directed therapeutics.

Journal Article International journal of hyperthermia : the official journal of European Society for Hyperthermic Oncology, North American Hyperthermia Group · September 2008 PurposeRecent progress suggests that short peptide motifs can be engineered into biopolymers with specific temperature dependent behavior. This review discusses peptide motifs capable of thermo-responsive behavior, and broadly summarizes design ap ... Full text Cite

Surface plasmon optical study of the interfacial phase transition of elastinlike polypeptide grafted on gold.

Journal Article Biointerphases · September 2008 The conformational changes in elastinlike polypeptides (ELPs) grafted to a solid/solution interface via different architectures were studied using surface plasmon resonance spectroscopy and surface plasmon field-enhanced fluorescence spectroscopy (SPFS). S ... Full text Cite

PMSE 446-Architecture of polymer-drug conjugate controls in vivo fate and efficacy

Conference ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · August 17, 2008 Link to item Cite

Synthesis and characterization of a thermally-responsive tumor necrosis factor antagonist.

Journal Article J Control Release · August 7, 2008 Numerous antagonists of tumor necrosis factor alpha (TNFalpha) have been developed to attenuate inflammation and accompanying pain in many disease processes. Soluble TNF receptor type II (sTNFRII) is one such antagonist that sequesters TNFalpha away from t ... Full text Link to item Cite

Distance-dependent plasmon resonant coupling between a gold nanoparticle and gold film.

Journal Article Nano letters · August 2008 We present an experimental analysis of the plasmonic scattering properties of gold nanoparticles controllably placed nanometers away from a gold metal film. We show that the spectral response of this system results from the interplay between the localized ... Full text Cite

Hydration and Conformational Mechanics of Single, End-Tethered Elastin-like Polypeptides

Journal Article Journal of the American Chemical Society · August 1, 2008 Full text Cite

In situ crosslinking elastin-like polypeptide gels for application to articular cartilage repair in a goat osteochondral defect model.

Journal Article Tissue engineering. Part A · July 2008 The objective of this study was to evaluate an injectable, in situ crosslinkable elastin-like polypeptide (ELP) gel for application to cartilage matrix repair in critically sized defects in goat knees. One cylindrical, osteochondral defect in each of seven ... Full text Cite

PMSE 206-Architecture of polymer-drug conjugate controls in vivo fate and efficacy

Conference ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · April 6, 2008 Link to item Cite

POLY 351-Thermally responsive elastin biopolymers for drug delivery

Conference ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · April 6, 2008 Link to item Cite

An injectable and in situ-gelling biopolymer for sustained drug release following perineural administration.

Journal Article Spine (Phila Pa 1976) · April 1, 2008 STUDY DESIGN: This study evaluated whether the aggregation behavior of a thermally responsive elastin-like polypeptide (ELP) prolongs protein residence time at the dorsal root ganglion (DRG). This work involves development of a sustained-release drug deliv ... Full text Link to item Cite

Label-free plasmonic detection of biomolecular binding by a single gold nanorod.

Journal Article Analytical chemistry · February 2008 We report the use of individual gold nanorods as plasmonic transducers to detect the binding of streptavidin to individual biotin-conjugated nanorods in real time on a surface. Label-free detection at the single-nanorod level was performed by tracking the ... Full text Cite

Peptide-based Biopolymers in Biomedicine and Biotechnology.

Journal Article Materials science & engineering. R, Reports : a review journal · January 2008 Peptides are emerging as a new class of biomaterials due to their unique chemical, physical, and biological properties. The development of peptide-based biomaterials is driven by the convergence of protein engineering and macromolecular self-assembly. This ... Full text Cite

Temperature triggered self-assembly of polypeptides into multivalent spherical micelles.

Journal Article Journal of the American Chemical Society · January 2008 We report herein thermally responsive elastin-like polypeptides (ELPs) in a linear AB diblock architecture with an N-terminal peptide ligand that self-assemble into spherical micelles when heated slightly above body temperature. A series of 10 ELP block co ... Full text Cite

In situ cross-linking of elastin-like polypeptide block copolymers for tissue repair.

Journal Article Biomacromolecules · January 2008 Rapid cross-linking of elastin-like polypeptides (ELPs) with hydroxymethylphosphines (HMPs) in aqueous solution is attractive for minimally invasive in vivo implantation of biomaterials and tissue engineering scaffolds. In order to examine the independent ... Full text Cite

Photothermal optical coherence tomography for molecular contrast imaging

Journal Article Biomedical Optics, BIOMED 2008 · January 1, 2008 Photothermal optical coherence tomography with laser-heated gold nanorods as the photothermal source is proposed as a novel molecular imaging technique. A description of the technique and validation experiments are reported. © Optical Society of America. ... Full text Cite

Single molecule nanomechanics of HIV-1 envelope glycoproteins and elastin-like polypeptides

Journal Article Proceedings of the SEM Annual Conference and Exposition on Experimental and Applied Mechanics 2007 · November 19, 2007 Cite

Surface-initiated enzymatic polymerization of DNA.

Journal Article Langmuir : the ACS journal of surfaces and colloids · November 2007 We describe a technique to synthesize DNA homopolymers on a surface using surface-initiated enzymatic polymerization (SIEP) with terminal deoxynucleotidyl transferase (TdTase), an enzyme that repetitively adds mononucleotides to the 3'-end of oligonucleoti ... Full text Cite

Development and characterization of a fusion protein between thermally responsive elastin-like polypeptide and interleukin-1 receptor antagonist: sustained release of a local antiinflammatory therapeutic.

Journal Article Arthritis Rheum · November 2007 OBJECTIVE: Interleukin-1 receptor antagonist (IL-1Ra) has been evaluated for the intraarticular treatment of osteoarthritis. Such administration of proteins may have limited utility because of their rapid clearance and short half-life in the joint. The fus ... Full text Link to item Cite

Elastin biopolymers for drug delivery

Journal Article ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · August 19, 2007 Link to item Cite

POLY 627-Fabrication of bioconjugated and hybrid polymeric nanostructures by field-induced scanning probe lithography

Journal Article ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · August 19, 2007 Link to item Cite

Toward a systems engineering approach to cancer drug delivery.

Journal Article Journal of the National Cancer Institute · July 2007 Full text Cite

Plasmonic detection of a model analyte in serum by a gold nanorod sensor.

Journal Article Analytical chemistry · July 2007 We describe the fabrication of a label-free, chip-based biosensor based on the localized surface plasmon resonance (LSPR) of gold nanorods. Gold nanorods were chemisorbed onto a mercaptosilane-modified glass substrate, followed by conjugation of biotin to ... Full text Cite

Force-induced prolyl cis-trans isomerization in elastin-like polypeptides.

Journal Article J Am Chem Soc · May 23, 2007 Elastin-like polypeptides (ELPs) are stimulus-responsive polymers that contain repeats of five amino acids, Val-Pro-Gly-Xaa-Gly (VPGXG), where Xaa is a guest residue that can be any amino acid with the exception of proline. While studying the conformationa ... Full text Link to item Cite

Improved non-chromatographic purification of a recombinant protein by cationic elastin-like polypeptides.

Journal Article Biomacromolecules · May 2007 This paper reports an improvement in the purification of thioredoxin (Trx) expressed from E. coli by inverse transition cycling (ITC) using cationic elastin-like polypeptides (ELPs). Two ELP libraries having 2% and 5% lysine residues and molecular weights ... Full text Cite

Rapid cross-linking of elastin-like polypeptides with (hydroxymethyl)phosphines in aqueous solution.

Journal Article Biomacromolecules · May 2007 In situ gelation of injectable polypeptide-based materials is attractive for minimally invasive in vivo implantation of biomaterials and tissue engineering scaffolds. We demonstrate that chemically cross-linked elastin-like polypeptide (ELP) hydrogels can ... Full text Cite

Thermal cycling enhances the accumulation of a temperature-sensitive biopolymer in solid tumors.

Journal Article Cancer Res · May 1, 2007 The delivery of anticancer therapeutics to solid tumors remains a critical problem in the treatment of cancer. This study reports a new methodology to target a temperature-responsive macromolecular drug carrier, an elastin-like polypeptide (ELP) to solid t ... Full text Link to item Cite

Analysis of total uncertainty in spectral peak measurements for plasmonic nanoparticle-based biosensors.

Journal Article Applied optics · April 2007 One goal of recent research on plasmonic nanoparticle-based sensors is maximizing nanoparticle sensitivity or shift of resonance peak wavelength per refractive index change. Equally important is a measurement system's peak location uncertainty or shift res ... Full text Cite

Microcantilever sensing and actuation with end-grafted stimulus-responsive elastin-like polypeptides.

Journal Article Langmuir : the ACS journal of surfaces and colloids · January 2007 Stimulus-responsive elastin-like polypeptides (ELPs) grafted onto surfaces are of significant technical interest because they can be exploited for force generation, in sensing applications, or as molecular switches with tunable properties. Changes in the c ... Full text Cite

Biomedical and biotechnological applications of Elastin-like polypeptides

Journal Article Polymer Reviews · January 1, 2007 Elastin-like polypeptides (ELPs) are a unique class of genetically encoded biopolymers with tunable thermosensitivity and biocompatibility. This review provides an introduction to ELPs and an overview of their design and synthesis. It also discusses applic ... Full text Cite

Fabrication of fiber-optic sensors based on plasmon resonances of metallic nanostructures

Journal Article ECS Transactions · January 1, 2007 This paper describes the fabrication of portable and robust fiber optic sensors - mainly chemical and biological sensors - on standard communication grade optical fibers. Metallic nanostructures such as nanoparticles, nanopillars, nanorods, and nanoholes i ... Full text Cite

Stimulus responsive elastin biopolymers: Applications in medicine and biotechnology.

Journal Article Current opinion in chemical biology · December 2006 Elastin-like polypeptides (ELPs) are artificial polypeptides, derived from Val-Pro-Gly-Xaa-Gly (VPGXG) pentapeptide repeats found in human tropoelastin, that reversibly coacervate above a critical temperature. Genetically encodable ELPs are monodisperse, s ... Full text Cite

Tumor accumulation, degradation and pharmacokinetics of elastin-like polypeptides in nude mice.

Journal Article J Control Release · November 28, 2006 ELPs are genetically engineered, thermally responsive polypeptides that preferentially accumulate in solid tumors subjected to focused, mild hyperthermia. In this paper, we report the biodegradation, pharmacokinetics, tumor localization, and tumor spatial ... Full text Link to item Cite

Tumor accumulation, degradation and pharmacokinetics of elastin-like polypeptides in nude mice

Journal Article Journal Of Controlled Release · November 2006 ELPs are genetically engineered, thermally responsive polypeptides that preferentially accumulate in solid tumors subjected to focused, mild hyperthermia. In this paper, we report the biodegradation, pharmacokinetics, tumor localization, and tumor spatial ... Cite

A thermally responsive biopolymer for intra-articular drug delivery.

Journal Article J Control Release · October 10, 2006 Intra-articular drug delivery is the preferred standard for targeting pharmacologic treatment directly to joints to reduce undesirable side effects associated with systemic drug delivery. In this study, a biologically based drug delivery vehicle was design ... Full text Link to item Cite

Purification of an elastin-like fusion protein by microfiltration.

Journal Article Biotechnology and bioengineering · October 2006 This article describes a simple and potentially scalable microfiltration method for purification of recombinant proteins. This method is based on the fact that when an elastin-like polypeptide (ELP) is fused to a target protein, the inverse phase transitio ... Full text Cite

Tracking the in vivo fate of recombinant polypeptides by isotopic labeling.

Journal Article J Control Release · August 28, 2006 We report a method to incorporate a stable isotope (13C) and a radioactive isotope (14C) into a recombinant polypeptide during Escherichia coli culture in M9 minimal medium supplemented with universally labeled 13C- or 14C-labeled glucose. We chose a therm ... Full text Link to item Cite

Ultra-high expression of a thermally responsive recombinant fusion protein in E. coli.

Journal Article Biotechnology progress · May 2006 Elastin-like polypeptides (ELPs) are recombinant peptide-based biopolymers that contain repetitive sequences enriched in glycine, valine, proline, and alanine. Because of the unusually large fraction of these amino acids in ELPs as compared to other cellul ... Full text Cite

Analysis of long range correlations due to coherent light scattering from in-vitro cell arrays using angle-resolved low coherence interferometry.

Journal Article Journal of biomedical optics · May 2006 Angle-resolved low coherence interferometry (a/LCI) enables depth-resolved measurements of scattered light that can be used to recover subsurface structural information, such as the size of cell nuclei. Measurements of nuclear morphology, however, can be c ... Full text Cite

Protein-resistant polymer coatings on silicon oxide by surface-initiated atom transfer radical polymerization.

Journal Article Langmuir : the ACS journal of surfaces and colloids · April 2006 The modification of silicon oxide with poly(ethylene glycol) to effectively eliminate protein adsorption has proven to be technically challenging. In this paper, we demonstrate that surface-initiated atom transfer radical polymerization (SI-ATRP) of oligo( ... Full text Cite

Bionanofabrication with polymers and enzymes

Journal Article ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · March 26, 2006 Link to item Cite

Surface-initiated atom transfer radical polymerization of oligo(ethylene glycol) methyl methacrylate from a mixed self-assembled monolayer on gold

Journal Article Advanced Functional Materials · March 20, 2006 This paper describes the in-situ synthesis of an oligo(ethylene glycol)-functionalized polymer brush in which the oligo(ethylene glycol) chains are presented as side-chains from a methacrylate backbone that is anchored to the surface. These polymer "bottle ... Full text Cite

Monitoring kinetics of surface initiated atom transfer radical polymerization by quartz crystal microbalance with dissipation.

Journal Article Biointerphases · March 2006 This article reports that the kinetics of surface-initiated atom transfer radical polymerization can be quantified by the quartz crystal microbalance with dissipation (QCM-D) technique. The kinetics of in situ growth of poly(oligoethylene glycol methylmeth ... Full text Cite

Epitope tagging for tracking elastin-like polypeptides.

Journal Article Biomaterials · March 2006 Elastin-like polypeptides (ELPs) are a class of biocompatible, non-immunogenic and crosslinkable biomaterials that offer promise for use as an injectable scaffold for cartilage repair. In this study, an oligohistidine (His(6)) epitope tag was incorporated ... Full text Cite

Patterning cells in highly deformable microstructures: effect of plastic deformation of substrate on cellular phenotype and gene expression.

Journal Article Biomaterials · March 2006 We describe the fabrication of deformable microstructures by low-pressure-soft-microembossing (muSEmb) that provides in vitro experimental "test-beds" to investigate the interplay of mechanical and chemical stimuli on cell behavior in a highly controlled e ... Full text Cite

Tumor vascular permeability, accumulation, and penetration of macromolecular drug carriers.

Journal Article J Natl Cancer Inst · March 1, 2006 BACKGROUND: Delivery of anticancer therapeutic agents to solid tumors is problematic. Macromolecular drug carriers are an attractive alternative drug delivery method because they appear to target tumors and have limited toxicity in normal tissues. We inves ... Full text Link to item Cite

Measurement system for the high-throughput characterization of metal nanoparticles for biosensors

Journal Article Optics InfoBase Conference Papers · January 1, 2006 We present a system for the rapid characterization of nanoparticles for biosensors, providing concurrent atomic force microscopy and scattering spectra of individual nanoparticles and simultaneous spectra from various nanostructures created by electron bea ... Cite

Chondrocytic differentiation of human adipose-derived adult stem cells in elastin-like polypeptide.

Journal Article Biomaterials · January 2006 Human adipose derived adult stem (hADAS) cells have the ability to differentiate into a chondrogenic phenotype in three-dimensional culture and media containing dexamethasone and TGF-beta. The current study examined the potential of a genetically engineere ... Full text Cite

Structural optimization of a "smart" doxorubicin-polypeptide conjugate for thermally targeted delivery to solid tumors.

Journal Article Journal of controlled release : official journal of the Controlled Release Society · January 2006 A thermoresponsive, genetically engineered, elastin-like polypeptide (ELP) containing a C-terminal cysteine residue was synthesized and purified by inverse transition cycling (ITC) and conjugated to doxorubicin (Dox) molecules through four different pH-sen ... Full text Cite

Aqueous two-phase system formation kinetics for elastin-like polypeptides of varying chain length

Journal Article Biomacromolecules · 2006 The kinetics of aqueous two-phase system (ATPS) formation for elastin-like polypeptides (ELP) with defined chemical composition and chain length was investigated by dark field microscopy in an on-chip format with a linear temperature gradient. Scattering i ... Full text Link to item Cite

Predictive modeling of polypeptide hydrogel mechanical properties for cartilage repair using artificial neural networks

Journal Article Proceedings of the 2005 Summer Bioengineering Conference · December 1, 2005 Cite

Materials Research Society Symposium Proceedings: Preface

Journal Article Materials Research Society Symposium Proceedings · December 1, 2005 Cite

Synthesis and in vitro evaluation of enzymatically cross-linked elastin-like polypeptide gels for cartilaginous tissue repair.

Journal Article Tissue engineering · November 2005 Genetically engineered elastin-like polypeptide (ELP) hydrogels offer unique promise as scaffolds for cartilage tissue engineering because of the potential to promote chondrogenesis and to control mechanical properties. In this study, we designed and synth ... Full text Cite

Enzymatic fabrication of DNA nanostructures: extension of a self-assembled oligonucleotide monolayer on gold arrays.

Journal Article Journal of the American Chemical Society · October 2005 Nucleic acid nanostructures are useful as templates for bionanofabrication of composite molecular nanostructures in materials science, molecular electronics, and biosensing. Here, we demonstrate that terminal deoxynucleotidyl transferase, which repetitivel ... Full text Cite

Targeted drug delivery to solid tumors by thermally responsive polypeptides

Journal Article European Cells and Materials · September 1, 2005 Cite

Stimulus-responsive elastin-like polypetides as coatings for microcantilevers: Applications for sensing and actuation

Journal Article ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · August 28, 2005 Link to item Cite

Passive and active surfaces to control protein and cell interactions

Journal Article ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · August 28, 2005 Link to item Cite

Rapid fabrication of DNA nanostructures by enzymatic reactions

Journal Article ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · August 28, 2005 Link to item Cite

Self-cleavable stimulus responsive tags for protein purification without chromatography.

Journal Article Journal of the American Chemical Society · August 2005 A simple method to purify recombinant proteins is described by fusing a target protein with an intein and an elastin-like polypeptide that only requires NaCl, dithiothreitol, and a syringe filter to isolate the target protein from Escherichia coli lysate. ... Full text Cite

Substrate effect on refractive index dependence of plasmon resonance for individual silver nanoparticles observed using darkfield microspectroscopy.

Journal Article Optics express · April 2005 We use optical darkfield micro-spectroscopy to characterize the plasmon resonance of individual silver nanoparticles in the presence of a substrate. The optical system permits multiple individual nanoparticles to be identified visually for simultaneous spe ... Full text Cite

Nano- to micro-scale structures of polymers that repel and attract proteins.

Journal Article ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · March 13, 2005 Link to item Cite

Biointerface Science

Journal Article MRS Bulletin · March 2005 AbstractBiointerface science, defined as the study and control of biomolecular interactions at surfaces, is a critical component of many aspects of biotechnology, but it has only recently begun to attract the attention it d ... Full text Cite

Measurement system for the high-throughput characterization of metal nanoparticles for biosensors

Journal Article Optics InfoBase Conference Papers · January 1, 2005 We present a system for the rapid characterization of nanoparticles for biosensors, providing concurrent atomic force microscopy and scattering spectra of individual nanoparticles and simultaneous spectra from various nanostructures created by electron bea ... Cite

Nanofabrication with biomolecules

Journal Article Materials Today · January 1, 2005 The advances made in biotechnology and nanotechnology for building complex bionanostructures on surfaces with nanometer precision are discussed. The use of biomolecules for nanoscale has become an effective solution for difficult positioning problems in th ... Full text Cite

Pretreatment of amphiphilic comb polymer surfaces dramatically affects protein adsorption

Journal Article Biomacromolecules · 2005 New applications in regenerative biotechnology require the ability to understand and control protein- surface interactions on micrometer and submicrometer length scales. Evidence presented here shows that micropatterned amphiphilic comb polymer films exhib ... Full text Link to item Cite

Fabrication of biofunctionalized quasi-three-dimensional microstructures of a nonfouling comb polymer using soft lithography

Journal Article Adv. Funct. Mater. (Germany) · 2005 This paper describes a simple set of patterning methods that are applicable to diverse substrates and allow the routine and rapid fabrication of protein patterns embedded within a background that consists of quasi-three-dimensional microstructures of a cel ... Full text Link to item Cite

Polypeptide-solvent interactions measured by single molecule force spectroscopy

Journal Article Materials Research Society Symposium Proceedings · 2005 Stimulus-responsive biomolecules have attracted a large research interest because of their potential application in various areas such as drug delivery, actuators and sensing devices at the nanoscale. Using single-molecule force spectroscopy (SMFS) we stud ... Cite

Measurement system for the high-throughput characterization of metal nanoparticles for biosensors

Journal Article 2005 Conference on Lasers and Electro-Optics, CLEO · January 1, 2005 We present a system for the rapid characterization of nanoparticles for biosensors, providing concurrent atomic force microscopy and scattering spectra of individual nanoparticles and simultaneous spectra from various nanostructures created by electron bea ... Full text Cite

Materials Research Society Symposium Proceedings: Preface

Conference Materials Research Society Symposium Proceedings · December 1, 2004 Cite

Expression and purification of recombinant proteins from Escherichia coli: Comparison of an elastin-like polypeptide fusion with an oligohistidine fusion.

Journal Article Protein science : a publication of the Protein Society · December 2004 Thermally responsive elastin like polypeptides (ELPs) can be used to purify proteins from Escherichia coli culture when proteins are expressed as a fusion with an ELP. Nonchromatographic purification of ELP fusion proteins, termed inverse transition cyclin ... Full text Cite

Surface engineering strategies for control of protein and cell interactions

Journal Article Surface Science · October 10, 2004 Surface engineering is an important tool in understanding the molecular mechanism of protein adsorption and cell-surface interactions with the aim of rational design of surfaces for different biological applications. This article first briefly summarizes s ... Full text Cite

Nitroxide conjugate of a thermally responsive elastin-like polypeptide for noninvasive thermometry.

Journal Article Med Phys · October 2004 Hyperthermia, as an adjuvant with radiation and chemotherapy, has shown promise in the treatment of cancer. The relevant biological effects of a hyperthermia treatment are both time and temperature-dependent, creating a need for accurate thermometry. We pr ... Full text Link to item Cite

Label-free biosensing by surface plasmon resonance of nanoparticles on glass: optimization of nanoparticle size.

Journal Article Analytical chemistry · September 2004 The unique optical properties of noble metal nanoparticles have been used to design a label-free biosensor in a chip format. In this paper, we demonstrate that the size of gold nanoparticles significantly affects the sensitivity of the biosensor. Gold nano ... Full text Cite

Mechanics of stimulus-responsive elastin-like polypeptides studied by force spectroscopy.

Conference ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · August 22, 2004 Link to item Cite

Label free colorimetric biosensing using nanoparticles.

Journal Article Journal of fluorescence · July 2004 In this review article, we discuss a class of biosensors that exploit the change in the colorimetric properties of noble metal nanoparticles in response to biomolecular binding at their surface. Several sensor fabrication techniques as well as sensor confi ... Full text Cite

Capture and release of proteins on the nanoscale by stimuli-responsive elastin-like polypeptide "switches".

Journal Article Journal of the American Chemical Society · June 2004 This article describes the fabrication and characterization of stimulus-responsive elastin-like polypeptide (ELP) nanostructures grafted onto omega-substituted thiolates that were patterned onto gold surfaces by dip-pen nanolithography (DPN). In response t ... Full text Cite

Quantification of the effects of chain length and concentration on the thermal behavior of elastin-like polypeptides.

Journal Article Biomacromolecules · May 2004 At a specific temperature, elastin-like polypeptides (ELPs) undergo a sharp solubility transition that can be exploited in a variety of applications in biotechnology and medicine. The temperature of the transition varies with ELP sequence, molecular weight ... Full text Cite

Enzymatic nanolithography of a self-assembled oligonucleotide monolayer on gold.

Journal Article Journal of the American Chemical Society · April 2004 This paper describes a simple strategy to biochemically manipulate a surface at the nanoscale by enzyme dip-pen nanolithography using an endonuclease (DNase I) that is directly patterned on a self-assembled monolayer presenting a terminal oligonucleotide. ... Full text Cite

"Non-Fouling" Oligo(ethylene glycol)-Functionalized Polymer Brushes Synthesized by Surface-Initiated Atom Transfer Radical Polymerization

Journal Article Advanced Materials · February 17, 2004 The synthesis of (EG) n-functionalized polymer brushes of tunable thicknesses in the 5-50 nm range by surface initiated polymerization was discussed. It was shown that these polymer brushes exhibited no detectable adsorption of proteins, and were cell resi ... Full text Cite

Effect of protein fusion on the transition temperature of an environmentally responsive elastin-like polypeptide: a role for surface hydrophobicity?

Journal Article Protein engineering, design & selection : PEDS · January 2004 The limited throughput, scalability and high cost of protein purification by chromatography provide motivation for the development of non-chromatographic protein purification technologies that are cheaper and easier to implement in a high-throughput format ... Full text Cite

Effect of genetic circular permutation near the active site on the activity and stability of an enzyme inhibitor.

Journal Article Biomolecular engineering · January 2004 We report here the effect of circular permutation on the structure and function of a model protein tendamistat, a 74 amino acid competitive inhibitor of porcine pancreatic alpha-amylase. The activity and stability of wild type and two permuted tendamistat ... Full text Cite

3-D reconstruction of tumor vascular networks

Conference JOURNAL OF VASCULAR RESEARCH · January 1, 2004 Link to item Cite

Conformational Mechanics of Stimulus-Responsive Polypeptides

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · November 27, 2003 Stimulus-responsive polymers and polypeptides (SRPs) experience a significant entropic response when exposed to an environmental stimulus, such as a change in temperature. This phase transition directly affects polymer conformation and can potentially be h ... Full text Cite

Surface engineering strategies for control of protein and cell interactions

Journal Article European Cells and Materials · September 1, 2003 Cite

X-ray photoelectron spectroscopy as a tool for bio-surface analysis

Journal Article European Cells and Materials · September 1, 2003 Cite

Fabrication of "smart" protein nanostructures using molecular recognition and dip-pen nano-lithography.

Conference ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · September 1, 2003 Link to item Cite

Evaluation of an elastin-like polypeptide-doxorubicin conjugate for cancer therapy.

Journal Article Journal of controlled release : official journal of the Controlled Release Society · August 2003 Thermally responsive elastin-like polypeptides (ELPs) were synthesized by recombinant DNA techniques and conjugated to doxorubicin through an acid-labile hydrazone bond to enable release of the drug in the acidic environment of lysosomes. The thermal prope ... Full text Cite

Swelling and mechanical behaviors of chemically cross-linked hydrogels of elastin-like polypeptides.

Journal Article Biomacromolecules · May 2003 Genetically engineered elastin-like polypeptides consisting of Val-Pro-Gly-X-Gly repeats, where X was chosen to be Lys every 7 or 17 pentapeptides (otherwise X was Val), were synthesized and expressed in E. coli, purified, and chemically cross-linked using ... Full text Cite

Thermodynamically reversible addressing of a stimuli responsive fusion protein onto a patterned surface template

Journal Article Langmuir · March 4, 2003 The sensitivity of an elastin-like polypeptide (ELP) to environmental stimuli is used to reversibly immobilize a fusion partner, thioredoxin (TRX), onto a hydrophobia surface. An ELP, fused to TRX at its C-terminus, adsorbs onto a hydrophobic self-assemble ... Full text Cite

Nanoparticle biosensors

Conference ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · March 1, 2003 Link to item Cite

Passive and active nonfouling polymer grafts.

Conference ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · March 1, 2003 Link to item Cite

Fabrication of surface confined, stimulus-responsive polymer nanostructures using dip-pen nanolithography.

Conference ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · March 1, 2003 Link to item Cite

Dynamic addressing of a surface pattern by a stimuli-responsive fusion protein

Journal Article Advanced Materials · February 5, 2003 An overview is given of a dynamic protein patterning methodology, thermodynamically reversible addressing of proteins (TRAP), in which a recombinant, stimuli responsive polypeptide is used to dynamically address a fusion protein onto a micropatterned surfa ... Full text Cite

Fabrication of a reversible protein array directly from cell lysate using a stimuli-responsive polypeptide.

Journal Article Analytical chemistry · February 2003 We report a new method to reversibly bind proteins to a surface in a functionally active orientation directly from cell lysate by exploiting a thermodynamically reversible hydrophilic-hydrophobic lower critical solution temperature (LCST) transition exhibi ... Full text Cite

Effect of streptavidin affinity mutants on the integrin-independent adhesion of biotinylated endothelial cells.

Journal Article Biomaterials · February 2003 We have previously shown that the high-affinity streptavidin (SA)-biotin interaction enhanced the initial integrin-mediated adhesion of biotinylated endothelial cells to SA-coated surface by serving as an extrinsic bond to stabilize and enhance the intrins ... Full text Cite

Universal route to cell micropatterning using an amphiphilic comb polymer

Journal Article Advanced Materials · 2003 Micropatterning of localized chemical or biochemical domains has the potential to become a powerful tool to control the behavior of anchorage-dependent cells. However, several problems, such as the limited types of substrates that can be successfully patte ... Full text Link to item Cite

A colorimetric gold nanoparticle biosensor: Effect of particle size on sensitivity

Journal Article Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings · December 1, 2002 We have previously developed a label-free optical method to study biomolecular interactions in real time at the surface of an optically transparent substrate. The method relies on the change in the absorbance spectrum of a self-assembled monolayer of gold ... Cite

Elastin-like polypeptide-doxorubicin conjugates for cancer therapy

Journal Article Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings · December 1, 2002 Thermally responsive elastin-like polypeptides (ELP) were synthesized by recombinant DNA techniques and conjugated to doxorubicin through an acid labile bond. The thermal properties, release of doxorubicin, uptake of ELP, cytotoxicity and cellular localiza ... Cite

A two-step chondrocyte recovery system based on thermally sensitive elastin-like polypeptide scaffolds for cartilage tissue engineering

Journal Article Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings · December 1, 2002 A "two step" tissue engineering strategy was developed to promote rapid matrix accumulation in cartilage constructs in vitro. Chondrocytes expanded in monolayer were encapsulated and cultured in a genetically engineered, thermally sensitive elastin-like po ... Cite

Design of thermally responsive, recombinant polypeptide carriers for targeted drug delivery.

Journal Article Advanced drug delivery reviews · October 2002 In this article, we review recombinant DNA methods for the design and synthesis of amino acid-based biopolymers, and briefly summarize an approach, recursive directional ligation (RDL), that we have employed to synthesize oligomeric genes for such biopolym ... Full text Cite

Targeted drug delivery by thermally responsive polymers.

Journal Article Advanced drug delivery reviews · September 2002 This review article summarizes recent results on the development of macromolecular carriers for thermal targeting of therapeutics to solid tumors. This approach employs thermally responsive polymers in conjunction with targeted heating of the tumor. The tw ... Full text Cite

Characterization of a genetically engineered elastin-like polypeptide for cartilaginous tissue repair.

Journal Article Biomacromolecules · September 2002 Elastin-like polypeptides (ELPs) are artificial polypeptides with unique properties that make them attractive as a biomaterial for tissue-engineered cartilage repair. ELPs are composed of a pentapeptide repeat, Val-Pro-Gly-Xaa-Gly (Xaa is any amino acid ex ... Full text Cite

A colorimetric gold nanoparticle sensor to interrogate biomolecular interactions in real-time on a surface.

Journal Article ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · August 18, 2002 Link to item Cite

Micropatterns of a cell-adhesive peptide on an amphiphilic comb polymer film

Journal Article Langmuir · April 16, 2002 We report in this paper a generic method to modify the surfaces of common polymeric biomaterials that enables spatially resolved attachment and growth of mammalian cells in a biologically relevant milieu. We demonstrate that an amphiphilic comb polymer pre ... Full text Cite

Hybrid bioinorganic smart membranes that incorporate protein-based molecular switches

Journal Article Langmuir · March 5, 2002 Polypeptide- and protein-based components have the potential to greatly enhance the functional character of hybrid organic/inorganic materials by imparting recognition, actuation, or transduction properties to these materials. In this study, we demonstrate ... Full text Cite

Genetically encoded synthesis of protein-based polymers with precisely specified molecular weight and sequence by recursive directional ligation: examples from the elastin-like polypeptide system.

Journal Article Biomacromolecules · March 2002 We report a new strategy for the synthesis of genes encoding repetitive, protein-based polymers of specified sequence, chain length, and architecture. In this stepwise approach, which we term "recursive directional ligation" (RDL), short gene segments are ... Full text Cite

A colorimetric gold nanoparticle sensor to interrogate biomolecular interactions in real time on a surface.

Journal Article Analytical chemistry · February 2002 This paper presents a new label-free optical method to study biomolecular interactions in real time at the surface of an optically transparent substrate. The method relies on the change in the absorbance spectrum of a self-assembled monolayer of colloidal ... Full text Cite

Creating "smart" surfaces using stimuli responsive polymers

Journal Article Advanced Materials · 2002 "Smart" surfaces that modulate their physico-chemical properties in response to environmental triggers can be fabricated by functionalization of a surface with stimuli-responsive polymers (SRPs). This article summarizes different approaches to the fabricat ... Full text Link to item Cite

Molecular recognition-mediated fabrication of protein nanostructures by dip-pen lithography

Journal Article Nano Lett. (USA) · 2002 We describe the molecular recognition-mediated, stepwise fabrication of patterned protein nanostructures with feature sizes on the order of 200 nm. First, a self-assembled monolayer (SAM) of 16-mercaplohexadecanoic acid (MHA) is patterned onto gold by dip- ... Full text Link to item Cite

An immobilized gold nanoparticle sensor for label free optical detection of biomolecular interactions

Journal Article Proceedings of SPIE - The International Society for Optical Engineering · January 1, 2002 We present a new label free optical technique to study biomolecular interactions in real time on a surface. This method monitors changes in the absorbance spectrum of a monolayer of gold on glass as a function of biomolecular binding. Gold nanoparticles wi ... Full text Cite

Microstamping on an activated polymer surface: Patterning biotin and streptavidin onto common polymeric biomaterials

Journal Article Langmuir · October 2, 2001 Microstamping on an activated polymer surface (MAPS) is a methodology that enables biomolecules to be patterned on polymers with micrometer spatial resolution. MAPS combines homogeneous surface derivatization of a polymer to introduce a reactive functional ... Full text Cite

Enhanced uptake of a thermally responsive polypeptide by tumor cells in response to its hyperthermia-mediated phase transition.

Journal Article Cancer research · October 2001 Elastin-like polypeptides (ELPs) composed of a VPGXG repeat undergo a reversible phase transition in aqueous solution. They are hydrophilic and soluble in aqueous solution below their transition temperature (T(t)), but they become hydrophobic and aggregate ... Cite

Biomedical applications of genetically encoded elastin biopolymers.

Journal Article ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · August 1, 2001 Link to item Cite

Interfacial phase transition of an environmentally responsive elastin biopolymer adsorbed on functionalized gold nanoparticles studied by colloidal surface plasmon resonance.

Journal Article Journal of the American Chemical Society · August 2001 The change in optical properties of colloidal gold upon aggregation has been used to develop an experimentally convenient colorimetric method to study the interfacial phase transition of an elastin-like polypeptide (ELP), a thermally responsive biopolymer. ... Full text Cite

Surface-initiated free radical polymerization of polystyrene micropatterns on a self-assembled monolayer on gold

Journal Article Macromolecules · July 31, 2001 We describe the in situ synthesis of nanometer thick films of polystyrene (PS) on a self-assembled monolayer (SAM) on gold by surface-initiated free radical polymerization and further demonstrate that three-dimensional polymer structures with micrometer la ... Full text Cite

Drug targeting using thermally responsive polymers and local hyperthermia.

Journal Article J Control Release · July 6, 2001 We report a new thermal targeting method in which a thermally responsive drug carrier selectively accumulates in a solid tumor that is maintained above physiological temperature by externally applied, focused hyperthermia. We synthesized two thermally resp ... Full text Link to item Cite

Micropatterning biological molecules on a polymer surface using elastomeric microwells.

Journal Article Journal of the American Chemical Society · July 2001 Full text Cite

Protein purification by fusion with an environmentally responsive elastin-like polypeptide: effect of polypeptide length on the purification of thioredoxin.

Journal Article Biotechnology progress · July 2001 Elastin-like polypeptides (ELPs) undergo a reversible, soluble-to-insoluble phase transition in aqueous solution upon heating through a characteristic transition temperature (T(t)). Incorporating a terminal ELP expression tag into the gene of a protein of ... Full text Cite

Targeting a genetically engineered elastin-like polypeptide to solid tumors by local hyperthermia.

Journal Article Cancer Res · February 15, 2001 Elastin-like polypeptides (ELPs) are biopolymers of the pentapeptide repeat Val-Pro-Gly-Xaa-Gly that undergo an inverse temperature phase transition. They are soluble in aqueous solutions below their transition temperature (T1) but hydrophobically collapse ... Link to item Cite

Enhanced TOF-SIMS imaging of a micropatterned protein by stable isotope protein labeling.

Journal Article Analytical chemistry · January 2001 Patterning of biomolecules on surfaces is an increasingly important technological goal. Because the fabrication of biomolecule arrays often involves stepwise, spatially resolved derivatization of surfaces, spectroscopic imaging of these arrays is important ... Full text Cite

Microstamping of biological ligands on activated polymer surfaces

Journal Article Annals of Biomedical Engineering · December 1, 2000 A new methodology, microstamping onto an activated polymer surface (MAPS), is presented. The methodology enables biological ligands and proteins to be patterned onto the surface of polymers. Proof of principle is demonstrated by micropatterning amine-termi ... Cite

Ultraflat nanosphere lithography: functionalized nanostructures for biomedical applications

Journal Article Annals of Biomedical Engineering · December 1, 2000 A new method, so-called ultraflat nanosphere lithography (UNSL), was designed to create nanopatterned surfaces of minimal topography and defined size for different materials capable of self-assembly chemistry. The feasibility of the method was demonstrated ... Cite

Engineered fusion protein of an elastin-like polypeptide and autofluorescent proteins: a genetically encodable nanobiosensor

Journal Article Annals of Biomedical Engineering · December 1, 2000 An overview is given on the synthesis and characterization of a protein nanobiosensor produced by gene-level fusion of an elastin-like polypeptide (ELP) with green fluorescent protein (GFP) and its blue mutant (BFP). The sensor is generally encodable, and ... Cite

Elastin-like polypeptides as thermally targeted drug carriers

Journal Article Annals of Biomedical Engineering · December 1, 2000 Here, we present the tissue distribution of radiolabeled ELP carriers that were injected into athymic mice with implanted tumors (human glioma D54MG). We observed a two-fold increase in ELP accumulation when the tumor was heated versus unheated animals. St ... Cite

Founder's Award, Society for Biomaterials. Sixth World Biomaterials Congress 2000, Kamuela, HI,May 15-20, 2000. Really smart bioconjugates of smart polymers and receptor proteins.

Journal Article Journal of biomedical materials research · December 2000 Over the past 18 years we have been deeply involved with the synthesis and applications of stimuli-responsive polymer systems, especially polymer-biomolecule conjugates. This article summarizes our work with one of these conjugate systems, specifically pol ... Full text Cite

Molecular imaging of a micropatterned biological ligand on an activated polymer surface

Journal Article Langmuir · September 1, 2000 We report here molecular characterization of a new method derived from reactive microcontact printing - microstamping on an activated polymer surface (MAPS) - which enables biological ligands and proteins to be patterned on a polymer surface with a spatial ... Full text Cite

Microstamping of biological ligands on activated polymer surfaces.

Journal Article ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · March 26, 2000 Link to item Cite

Genetically engineered biopolymer conjugate for thermal targeting of anticancer therapeutics.

Journal Article ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · March 26, 2000 Link to item Cite

Genetically engineered polypeptide carrier for thermal targeting of anticancer therapeutics

Journal Article American Chemical Society, Polymer Preprints, Division of Polymer Chemistry · March 1, 2000 The thermally-responsive carrier, an elastin-like polypeptide (ELP), is an oligomer of a Val-Pro-Gly-Xaa-Gly pentapeptide repeat. Below a specific, inverse phase transition temperature (Tt), ELPs are highly soluble in aqueous solution. However, upon raisin ... Cite

Molecular engineering of proteins and polymers for targeting and intracellular delivery of therapeutics.

Journal Article Journal of controlled release : official journal of the Controlled Release Society · March 2000 There are many protein and DNA based therapeutics under development in the biotechnology and pharmaceutical industries. Key delivery challenges remain before many of these biomolecular therapeutics reach the clinic. Two important barriers are the effective ... Full text Cite

Engineered fusion protein of an elastin-like polypeptide and autofluorescent proteins: a genetically encodable nanobiosensor

Journal Article Annals of Biomedical Engineering · 2000 An overview is given on the synthesis and characterization of a protein nanobiosensor produced by gene-level fusion of an elastin-like polypeptide (ELP) with green fluorescent protein (GFP) and its blue mutant (BFP). The sensor is generally encodable, and ... Cite

Microstamping of biological ligands on activated polymer surfaces

Journal Article Annals of Biomedical Engineering · 2000 A new methodology, microstamping onto an activated polymer surface (MAPS), is presented. The methodology enables biological ligands and proteins to be patterned onto the surface of polymers. Proof of principle is demonstrated by micropatterning amine-termi ... Cite

Microstamping of a biological ligand onto an activated polymer surface

Journal Article Advanced Materials · 2000 A method for patterning biological ligands and proteins were patterned onto polymer surfaces is described. Called microstamping onto an activated polymer surface (MAPS), the method is based on a reaction between a microcontact-printed biological ligand and ... Full text Link to item Cite

Really smart bioconjugates of smart polymers and receptor proteins

Journal Article Journal of Biomedical Materials Research · 2000 Over the past 18 years we have been deeply involved with the synthesis and applications of stimuliresponsive polymer systems, especially polymer-biomolecule conjugates. This article summarizes our work with one of these conjugate systems, specifically poly ... Full text Link to item Cite

Ultraflat nanosphere lithography: functionalized nanostructures for biomedical applications

Journal Article Annals of Biomedical Engineering · 2000 A new method, so-called ultraflat nanosphere lithography (UNSL), was designed to create nanopatterned surfaces of minimal topography and defined size for different materials capable of self-assembly chemistry. The feasibility of the method was demonstrated ... Cite

Ultraflat nanosphere lithography: a new method to fabricate flat nanostructures

Journal Article Adv. Mater. (Germany) · 2000 Ultraflat nanopatterned surfaces can be created by combining the techniques of nanosphere lithography and ultraflat template stripping, as highlighted here. In this new method-ultraflat nanosphere lithography (UNSL)-nanostructures of one material are embed ... Full text Link to item Cite

Light-activated affinity micropatterning of proteins on self-assembled monolayers on gold

Journal Article Langmuir (USA) · 2000 We describe a method to pattern proteins onto a photolabile “caged” biotin-derivatized self-assembled monolayer (SAM) on gold, which we term light-activated affinity micropatterning of proteins (LAMP). LAMP is a multistep patterning process wit ... Full text Link to item Cite

Streptavidin-biotin binding energetics.

Journal Article Biomolecular engineering · December 1999 The high affinity energetics in the streptavidin-biotin system provide an excellent model system for studying how proteins balance enthalpic and entropic components to generate an impressive overall free energy for ligand binding. We review here concerted ... Full text Cite

X-ray crystallographic studies of streptavidin mutants binding to biotin.

Journal Article Biomolecular engineering · December 1999 On the basis of high resolution crystallographic studies of streptavidin and its biotin complex, three principal binding motifs have been identified that contribute to the tight binding. A flexible binding loop can undergo a conformational change from an o ... Full text Cite

Direct force measurements of the streptavidin-biotin interaction.

Journal Article Biomolecular engineering · December 1999 The interaction between streptavidin and its ligand, biotin, were studied by direct force measurements. The complimentary approaches of surface force apparatus (SFA) and atomic force microscopy (AFM) were used to elucidate both long-range and short-range a ... Full text Cite

Controlling the orientation of immobilized proteins by genetic circular permutation

Journal Article Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings · December 1, 1999 Controlling the orientation of immobilized proteins is critical to their surface activity. However, most currently used protein immobilization strategies result in a wide range of surface orientations. Because termini are ubiquitous to proteins, we have in ... Cite

Light-activated affinity micropatterning of proteins

Journal Article Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings · December 1, 1999 Protein micropatterning has attracted considerable interest because of its prospective application in the fabrication of biosensors and tissue engineering substrates. Motivated by these potential applications, we have developed a method to micropattern pro ... Cite

Genetically-engineered polypeptide carrier for thermal targeting of therapeutics

Journal Article Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings · December 1, 1999 We report the synthesis of a environmentally-responsive polypeptide carrier for thermally-targeted delivery of radionuclide therapeutics. We hypothesized that systemically-injected radionuclide-polypeptide conjugates are likely to be cleared from circulati ... Cite

Purification of recombinant proteins by fusion with thermally-responsive polypeptides.

Journal Article Nat Biotechnol · November 1999 Featured Publication Elastin-like polypeptides (ELPs) undergo a reversible, inverse phase transition. Below their transition temperature (Tt), ELPs are soluble in water, but when the temperature is raised above Tt, phase transition occurs, leading to aggregation of the polypep ... Full text Link to item Cite

Polypeptide fusion tag for thermal purification of recombinant proteins.

Journal Article ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY · March 21, 1999 Link to item Cite

Structural studies of binding site tryptophan mutants in the high-affinity streptavidin-biotin complex.

Journal Article Journal of molecular biology · May 1998 Previous thermodynamic and computational studies have pointed to the important energetic role of aromatic contacts in generating the exceptional binding free energy of streptavidin-biotin association. We report here the crystallographic characterization of ... Full text Cite

Conjugates of Stimuli-Responsive Polymers and Biomolecules: Random and Site-Specific Conjugates of Temperature-Sensitive Polymers and Proteins

Journal Article Macromolecular Symposia · January 1, 1997 Intelligent polymers exhibit sharp, reversible phase changes in response to small changes in environmental conditions. For example, a small temperature change can cause a sharp precipitation or gelation of a smart polymer solution. Conjugation of these unu ... Full text Cite

Site-specific conjugation of a temperature-sensitive polymer to a genetically-engineered protein

Journal Article Transactions of the Annual Meeting of the Society for Biomaterials in conjunction with the International Biomaterials Symposium · December 1, 1996 A novel method for sensitive environmental control of the molecular recognition process between a protein receptor and its ligand is presented. The method is based on the conjugation of a smart, temperature-sensitive polymer, poly(N-isopropylacrylamide), t ... Cite

Two-dimensional protein crystallization via metal-ion coordination by naturally occurring surface histidines.

Journal Article Proceedings of the National Academy of Sciences of the United States of America · May 1996 A powerful and potentially general approach to the targeting and crystallization of proteins on lipid interfaces through coordination of surface histidine residues to lipid-chelated divalent metal ions is presented. This approach, which should be applicabl ... Full text Cite

The relationship between ligand-binding thermodynamics and protein-ligand interaction forces measured by atomic force microscopy.

Journal Article Biophysical journal · November 1995 The interaction forces between biotin and a set of streptavidin site-directed mutants with altered biotin-binding equilibrium and activation thermodynamics have been measured by atomic force microscopy. The AFM technique readily discriminates differences i ... Full text Cite

Engineered chimeric streptavidin tetramers as novel tools for bioseparations and drug delivery.

Journal Article Bio/technology (Nature Publishing Company) · November 1995 We report the construction of chimeric streptavidin tetramers that are composed of subunits of both wild-type (WT) streptavidin and genetically-engineered streptavidin variants designed for enhanced bioseparation and drug delivery performance. Subunit mixi ... Full text Cite

Control of protein-ligand recognition using a stimuli-responsive polymer.

Journal Article Nature · November 1995 Stimuli-responsive polymers exhibit reversible phase changes in response to changes in environmental factors such as pH or temperature. Conjugating such polymers to antibodies and proteins provides molecular systems for applications such as affinity separa ... Full text Cite

Investigating the relationship between surface chemistry and endothelial cell growth: partial least-squares regression of the static secondary ion mass spectra of oxygen-containing plasma-deposited films.

Journal Article Analytical chemistry · September 1995 The relationship between endothelial cell growth and surface properties of plasma-deposited films (PDFs) was investigated using partial least-squares regression (PLS). PDFs of oxygen-containing precursors were prepared under various conditions, and bovine ... Full text Cite

Dissociation of tetrameric ions of noncovalent streptavidin complexes formed by electrospray ionization.

Journal Article Journal of the American Society for Mass Spectrometry · June 1995 The noncovalent tetrameric association of the protein streptavidin formed by electrospray ionization (ESI) mass spectrometry has been observed intact and dissociated in the gas phase. An extended mass-to-charge ratio range quadrupole mass spectrometer was ... Full text Cite

Site-directed mutagenesis studies of the high-affinity streptavidin-biotin complex: contributions of tryptophan residues 79, 108, and 120.

Journal Article Proceedings of the National Academy of Sciences of the United States of America · February 1995 We report the functional characterization of site-directed biotin binding-site mutants of recombinant core streptavidin. The mutagenesis studies were aimed at characterizing the contributions of Trp residues known to contact biotin that have been postulate ... Full text Cite

Molecular Origins of the Slow Streptavidin—Biotin Dissociation Kinetics

Journal Article Journal of the American Chemical Society · January 1, 1995 The association of streptavidin and avidin with biotin is among the strongest known noncovalent protein-ligand interactions (Ka≈ 2.5 x 1013 M-1) and is controlled by an exceptionally slow off-rate. We have used this model system to elucidate the role of ar ... Full text Cite

Investigation of non‐covalent ligand binding to the intact streptavidin tetramer by electrospray ionization mass spectrometry

Journal Article Journal of Mass Spectrometry · January 1, 1995 The relative non‐covalent binding behavior of two small molecule ligands to the tetrameric protein streptavidin was investigated by electrospray ionization mass spectrometry (ESI‐MS). An extended m/z range quadrupole mass spectrometer was employed to obser ... Full text Cite

Site-specific conjugation of a temperature-sensitive polymer to a genetically-engineered protein.

Journal Article Bioconjugate chemistry · November 1994 A genetically-engineered mutant of cytochrome b5, incorporating a unique cysteine residue, was conjugated to maleimide-terminated oligo(N-isopropylacrylamide). The conjugation of the protein by reaction of the cysteine residue, precisely positioned by site ... Full text Cite

Static secondary ion mass spectrometric investigation of the surface chemistry of organic plasma-deposited films created from oxygen-containing precursors. 3. Multivariate statistical modeling.

Journal Article Analytical chemistry · July 1993 Partial least squares (PLS) multivariate statistical models were developed to predict the surface composition and chemistry of a set of model homopolymers based on their static SIMS fragmentation patterns. In the calibration or model-building step, the pos ... Full text Cite

Analysis of biomedical polymer surfaces: polyurethanes and plasma-deposited thin films.

Journal Article Clinical materials · January 1993 The surface characterization of biomaterials is important for understanding the biological reactivity of surfaces and for monitoring surface reproducibility and contamination. Electron spectroscopy for chemical analysis (ESCA), secondary ion mass spectrom ... Full text Cite

Analysis of Polymer Surfaces by SIMS. 16. Investigation of Surface Cross-Linking in Polymer Gels of 2-Hydroxyethyl Methacrylate

Journal Article Macromolecules · January 1, 1993 A series of poly(2-hydroxyethyl methacrylate) gels cross-linked with different concentrations of ethylene glycol dimethacrylate were examined by static secondary ion mass spectrometry (SIMS). Changes in the peak intensities of atomic versus molecular secon ... Full text Cite

Engineered proteins for biomaterials

Journal Article Materials Research Society Symposium Proceedings · January 1, 1993 A molecular adaptor for interfacing environmentally sensitive, soluble polymers and antibody molecules has been developed. The gene coding for the minimally sized, 55 amino acid IgG binding domain from protein G has been constructed by total gene synthesis ... Cite

X-ray Photoelectron Spectroscopy of Iodine-Doped Nonconjugated Polymers

Journal Article Chemistry of Materials · January 1, 1993 The effects of iodine doping on poly(cis-butadiene) and the cis and trans isomers of polyisoprene were examined by core-level X-ray photoelectron spectroscopy (XPS). The XPS results for iodine-doped poly(cis-butadiene) are similar to that for polyisoprene, ... Full text Cite

A tandem SIMS study of poly(vinyl methyl ether)

Journal Article Surface and Interface Analysis · January 1, 1992 Results are presented for a tandem‐SIMS investigation of the fragmentation patterns of secondary ions sputtered from the surface of poly(vinyl methyl ether) (PVME). A complete fragmentation sequence is deduced which is capable of explaining the formation o ... Full text Cite

Analysis of polymer surfaces by SIMS: Part 15. Oxygen‐functionalized aliphatic homopolymers

Journal Article Surface and Interface Analysis · January 1, 1992 The positive and negative ion spectra from simple oxygen‐containing aliphatic homopolymers (i.e. ethers, ketones, carboxylates and backbone esters) are reported. Interpretation of the static SIMS fragmentation patterns of these polymers is shown to be rela ... Full text Cite

Static secondary ion mass spectrometry of organic plasma‐deposited films created from stable isotope‐labeled precursors. II. Mixtures of acetone and oxygen

Journal Article Journal of Polymer Science Part A: Polymer Chemistry · January 1, 1992 A series of plasma‐deposited films (PDFs), created by blending controlled ratios of acetone vapor and oxygen in the feed to the plasma reactor, were analyzed by static secondary ion mass spectrometry (SIMS). Examination of the quadrupole‐based static SIMS ... Full text Cite

Contemporary methods for characterizing complex biomaterial surfaces

Journal Article Clinical Materials · January 1, 1992 There are many methods that we can bring to bear for the characterization of polymeric surfaces. Standard methods include contact angle techniques, attenuated total reflectance infrared (IR) and electron spectroscopy for chemical analysis (ESCA). However, ... Full text Cite

Substrate temperature effects on film chemistry in plasma deposition of organics. III. Analysis by static secondary ion mass spectrometry

Journal Article Journal of Polymer Science Part A: Polymer Chemistry · January 1, 1992 Static secondary ion mass spectrometry (SIMS) was used to examine the effect of reducing the substrate temperature during the radio frequency plasma deposition of organic films. Studies of two polymerizable plasma precursors (2‐hydroxyethyl methacrylate an ... Full text Cite

Endothelial cell growth on oxygen-containing films deposited by radio-frequency plasmas: the role of surface carbonyl groups.

Journal Article Journal of biomaterials science. Polymer edition · December 1, 1991 Polystyrene substrates were modified by radio-frequency plasma deposition from mixtures of various organic vapors (acetone, methane, methanol, and formic acid) and oxygen. The resulting surfaces exhibited a wide range of surface oxygen concentrations, as m ... Cite

Direct emission of molecular fragments during the sputtering of poly(4-hydroxystyrene) and determination of ion structures using tandem secondary ion mass spectrometry

Journal Article International Journal of Mass Spectrometry and Ion Processes · September 2, 1991 Poly(4-hydroxystyrene) (P4HS) has been studied using a tandem secondary ion mass spectrometer under static conditions. The secondary ion mass spectrometry (SIMS) spectrum of P4HS exhibits few ions which are not observed in the SIMS spectrum of polystyrene. ... Full text Cite

Static secondary-ion mass spectrometric investigation of the surface structure of organic plasma-deposited films prepared from stable-isotope-labeled precursors. 1. Carbonyl precursors.

Journal Article Analytical chemistry · August 1991 Stable-isotope-labeled carbonyl precursors (acetaldehyde, acetone, and 2-butanone) were used to create plasma-deposited films (PDFs), which were then examined by positive- and negative-ion static SIMS. This allowed hydrocarbon (HC) fragments to be distingu ... Full text Cite

Static Secondary Ion Mass Spectrometry and X-Ray Photoelectron Spectroscopy of Deuterium- and Methyl-Substituted Polystyrene

Journal Article Applied Spectroscopy · February 1991 Denteration in polystyrene (PS) and the differences between PS, poly(4-methyl styrene) (P4MS), and poly( α-methyl styrene) (PAMS) were examined with static secondary ion mass spectrometry (SIMS) and x-ray photoelectron spectroscopy (XPS). Only the ... Full text Cite

An X‐ray photoelectron spectroscopic investigation of the selectivity of hydroxyl derivatization reactions

Journal Article Surface and Interface Analysis · January 1, 1991 The Selectivity of trifluoroacetic anhydride (TFAA), used for the vapor‐phase derivatization of hydroxyl groups in multifunctional oxygen‐containing polymeric surfaces, has been investigated by XPS studies on model epoxides systems. The reactivity of TFAA ... Full text Cite

Plasma-Deposited Polymeric Films Prepared from Carbonyl-Containing Volatile Precursors: XPS Chemical Derivatization and Static SIMS Surface Characterization

Journal Article Chemistry of Materials · January 1, 1991 The surface chemistry of plasma-deposited films (PDF) created from carbonyl precursors was investigated by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and vapor-phase derivatization reactions in conjunction with ... Full text Cite

Structural elucidation of oxygen-containing plasma deposited films by static secondary ion mass spectrometry

Journal Article Transactions of the Annual Meeting of the Society for Biomaterials in conjunction with the International Biomaterials Symposium · January 1, 1991 This study focusses on the use of static secondary ion mass spectrometry (SIMS) to unravel the surface chemistry of oxygen-containing organic PDF of interest in cell growth applications. The aims of this study are (1) to elucidate the identity of secondary ... Cite

Endothelial cell growth on oxygen-containing films deposited by radio-frequency plasmas: the role of surface carbonyl groups.

Journal Article Journal of biomaterials science. Polymer edition · January 1991 Polystyrene substrates were modified by radio-frequency plasma deposition from mixtures of various organic vapors (acetone, methane, methanol, and formic acid) and oxygen. The resulting surfaces exhibited a wide range of surface oxygen concentrations, as m ... Full text Cite

Surface characterization of a poly(styrene/p-hydroxystyrene) copolymer series using x-ray photoelectron spectroscopy, static secondary ion mass spectrometry, and chemical derivatization techniques

Journal Article Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films · January 1, 1990 A series of poly (styrene/p-hydroxystyrene) copolymers was examined by x-ray photoelectron spectroscopy (XPS), static secondary ion mass spectrometry (SIMS), and chemical derivatization, Static SIMS distinguished polystyrene (PS) and poly (p-hydroxystyrene ... Full text Cite

Static SIMS investigation of the surface structure of plasma deposited films prepared from stable isotope-labeled carbonyl precursors

Journal Article Polymeric Materials Science and Engineering, Proceedings of the ACS Division of Polymeric Materials Science and Engineering · January 1, 1990 The plasma deposition of organics is an emerging technology, permitting the formation of ultrathin films of technological interest on a variety of substrates. However, the thin film nature of plasma deposited films (PDF) and their complex chemistry, i.e., ... Cite

Effect of monomer type on the surface chemistry of rf-plasma deposited surfaces prepared for cell culture

Journal Article Polymeric Materials Science and Engineering, Proceedings of the ACS Division of Polymeric Materials Science and Engineering · December 1, 1988 The characterization techniques used reveal that the differences between plasma deposited films from the three monomers under identical reactor conditions are minor, which suggests that the monomer molecules undergo extensive fragmentation in the plasma; t ... Cite