Silicone-alginate-composite for cell based therapies: A novel silicone based implant material for immobilization of drug releasing cells

The characteristics of a silicone-alginate-composite are presented here. The composite consists of an interpenetrating network with an alginate phase forming joined pores within a silicone scaffold. Depending on the alginate content, the pore size is between 150 and 300 mm and water-soluble molecules are able to diffuse through the composite. Water contact angle measurements revealed a hydrophilic surface and composites containing high molecular weight alginate showed no cytotoxic effect at all. L929 cells were immobilized within the composite. The cells were able to survive and proliferate over a time period of 25 days. The silicone-alginate-composite is therefore suited to be used as an implant material, in which drug releasing cells can be immobilized to continuously release biologically active substances.