Proliferation and insulin secretion function of mouse insulinoma cells encapsulated in alginate/sol-gel synthesized aminopropyl-silicate/alginate microcapsule

Alginate/aminopropyl-silicate/alginate microcapsules, ca. 15 μm in membrane thickness and ca. 500 μm in diameter, were prepared via sol-gel process. The aminopropyl-silicate membrane was derived from two silicone alkoxide precursors, tetramethoxysilane and 3-aminopropyl-trimethoxysilane on Ca-alginate micro gel beads. Pancreatic β-cell line (MIN6) cells were encapsulated in the microcapsule. The encapsulated MIN6 cells proliferated and formed spheroidal tissues in vitro. The diameter of the MIN6 spheroids increased to approximately 250 μm with an increase in the incubation period until the day 35. Storeptozotocin-induced diabetic mice became normoglycemia after implantation of the MIN6-enclosing microcapsules. The normoglycemic state remained until the retrieval of the implanted microcapsules for 1 month. These results indicate that the potential use of the alginate/aminopropyl-silicate/alginate microcapsule as a vehicle for a genetically engineered cell-enclosing therapeutic material delivery system.