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Synthesis of multilayered alginate microcapsules for the sustained release of fibroblast growth factor‐1
Author(s) -
Khanna Omaditya,
Moya Monica L.,
Opara Emmanuel C.,
Brey Eric M.
Publication year - 2010
Publication title -
journal of biomedical materials research part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.849
H-Index - 150
eISSN - 1552-4965
pISSN - 1549-3296
DOI - 10.1002/jbm.a.32883
Subject(s) - materials science , glucuronic acid , neovascularization , fibroblast growth factor , growth factor , transplantation , biophysics , cell encapsulation , kinetics , fibroblast , chemical engineering , biomedical engineering , angiogenesis , polymer chemistry , chemistry , biochemistry , self healing hydrogels , biology , in vitro , surgery , polysaccharide , cancer research , medicine , engineering , receptor , physics , quantum mechanics
Abstract Alginate microcapsules coated with a permselective poly‐ L ‐ornithine (PLO) membrane have been investigated for the encapsulation and transplantation of islets as a treatment for type 1 diabetes. The therapeutic potential of this approach could be improved through local stimulation of microvascular networks to meet mass transport demands of the encapsulated cells. Fibroblast growth factor‐1 (FGF‐1) is a potent angiogenic factor with optimal effect occurring when it is delivered in a sustained manner. In this article, a technique is described for the generation of multilayered alginate microcapsules with an outer alginate layer that can be used for the delivery of FGF‐1. The influence of alginate concentration and composition (high mannuronic acid (M) or guluronic acid (G) content) on outer layer size and stability, protein encapsulation efficiency, and release kinetics was investigated. The technique results in a stable outer layer of alginate with a mean thickness between 113 and 164 μm, increasing with alginate concentration and G‐content. The outer layer was able to encapsulate and release FGF‐1 for up to 30 days, with 1.25% of high G alginate displaying the most sustained release. The released FGF‐1 retained its biologic activity in the presence of heparin, and the addition of the outer layer did not alter the permselectivity of the PLO coat. This technique could be used to generate encapsulation systems that deliver proteins to stimulate local neovascularization around encapsulated islets. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.