Multilayered microcapsules for the sustained-release of angiogenic proteins from encapsulated cells

BackgroundMultilayered alginate microcapsules with a permselective poly-L-ornithine membrane can be used for the dual purpose of encapsulating cells in the inner core and sustained release of angiogenic proteins from the outer layer. The aim of this study was to examine the encapsulation and release of a novel chimeric form of fibroblast growth factor–1 (FGF-1) from the outer layer of alginate microcapsules.MethodsHeparin-binding growth-associated molecule bound to FGF-1 (HB-GAM/FGF-1) was encapsulated in the outer layer of multilayered alginate microbeads constructed using varying alginate conditions. The encapsulation and release of the chimera was quantified.ResultsThe outer layer was able to encapsulate and release HB-GAM/FGF-1 for up to 30 days. The outer layer made with 1% alginate of high mannuronic acid content provided the fastest release, while 1.25% high guluronic acid content alginate displayed the longest duration of release.ConclusionsThe outer layer of multilayered alginate microbeads can be used for the encapsulation and long-term release of HB-GAM/FGF-1.