The phosphorylation of vascular endothelial growth factor receptor-2 (VEGFR-2) by engineered surfaces with electrostatically or covalently immobilized VEGF.

Published

Journal Article

Growth factors are a class of signaling proteins that direct cell fate through interaction with cell-surface receptors. Although a myriad of possible cell fates stems from a growth factor binding to its receptor, the signaling cascades that result in one fate over another are still being elucidated. One possible mechanism by which nature modulates growth factor signaling is through the method of presentation of the growth factor--soluble or immobilized (matrix bound). Here we present the methodology to study signaling of soluble versus immobilized VEGF through VEGFR-2. We have designed a strategy to covalently immobilize VEGF using its heparin-binding domain to orient the molecule (bind) and a secondary functional group to mediate covalent binding (lock). This bind-and-lock approach aims to allow VEGF to assume a bioactive orientation before covalent immobilization. Surface plasmon resonance (SPR) demonstrated heparin and VEGF binding with surface densities of 60 ng/cm2 and 100 pg/cm2, respectively. ELISA experiments confirmed VEGF surface density and showed that electrostatically bound VEGF releases in cell medium and heparin solutions while covalently bound VEGF remains immobilized. Electrostatically bound VEGF and covalently bound VEGF phosphorylate VEGFR-2 in both VEGFR-2 transfected cells and VEGFR-2 endogenously producing cells. HUVECs plated on VEGF functionalized surfaces showed different morphologies between surface-bound VEGF and soluble VEGF. The surfaces synthesized in these studies allow for the study of VEGF/VEGFR-2 signaling induced by covalently bound, electrostatically bound, and soluble VEGF and may provide further insight into the design of materials for the generation of a mature and stable vasculature.

Full Text

Duke Authors

Cited Authors

  • Anderson, SM; Chen, TT; Iruela-Arispe, ML; Segura, T

Published Date

  • September 2009

Published In

Volume / Issue

  • 30 / 27

Start / End Page

  • 4618 - 4628

PubMed ID

  • 19540581

Pubmed Central ID

  • 19540581

Electronic International Standard Serial Number (EISSN)

  • 1878-5905

International Standard Serial Number (ISSN)

  • 0142-9612

Digital Object Identifier (DOI)

  • 10.1016/j.biomaterials.2009.05.030

Language

  • eng