Synthesis of magnetic resonance-, X-ray- and ultrasound-visible alginate microcapsules for immunoisolation and noninvasive imaging of cellular therapeutics.

Published online

Journal Article

Cell therapy has the potential to treat or cure a wide variety of diseases. Non-invasive cell tracking techniques are, however, necessary to translate this approach to the clinical setting. This protocol details methods to create microcapsules that are visible by X-ray, ultrasound (US) or magnetic resonance (MR) for the encapsulation and immunoisolation of cellular therapeutics. Three steps are generally used to encapsulate cellular therapeutics in an alginate matrix: (i) droplets of cell-containing liquid alginate are extruded, using an electrostatic generator, through a needle tip into a solution containing a dissolved divalent cation salt to form a solid gel; (ii) the resulting gelled spheres are coated with polycations as a cross-linker; and (iii) these complexes are then incubated in a second solution of alginate to form a semipermeable membrane composed of an inner and an outer layer of alginate. The microcapsules can be rendered visible during the first step by adding contrast agents to the primary alginate layer. Such contrast agents include superparamagnetic iron oxide for detection by (1)H MR imaging (MRI); the radiopaque agents barium or bismuth sulfate for detection by X-ray modalities; or perfluorocarbon emulsions for multimodal detection by (19)F MRI, X-ray and US imaging. The entire synthesis can be completed within 2 h.

Full Text

Duke Authors

Cited Authors

  • Barnett, BP; Arepally, A; Stuber, M; Arifin, DR; Kraitchman, DL; Bulte, JWM

Published Date

  • July 14, 2011

Published In

Volume / Issue

  • 6 / 8

Start / End Page

  • 1142 - 1151

PubMed ID

  • 21799484

Pubmed Central ID

  • 21799484

Electronic International Standard Serial Number (EISSN)

  • 1750-2799

Digital Object Identifier (DOI)

  • 10.1038/nprot.2011.352


  • eng

Conference Location

  • England