CONTROLLED-RELEASE OF DOPAMINE, INSULIN AND OTHER AGENTS FROM MICROENCAPSULATED CELLS

Mammalian cells encapsulated within polymeric membranes is a novel way for in vivo controlled release of therapeutic agents. A permselective polymeric membrane, by acting as a permeability barrier for large mol ecules (such as antibodies) can protect the encapsulated cells from th e cytotoxic components of the host's tissue reaction without immunosup pressants. The high membrane permeability for small molecules (such as nutrients, hormones, etc.), on the other hand. will ensure the mainte nance of normal physiological state by the encapsulated cells. We have developed an interfacial precipitation technique for encapsulating ma mmalian cells in polyacrylate membranes. This technique is based on th e co-extrusion of a cell suspension and polymer solution through a con centric needle assembly and subsequent formation of a polymeric membra ne around the cells in a precipitation bath. Here, we report a summary of our experience with the performance of the encapsulated cells in h ydroxyethyl methacrylate-methyl methacrylate (HEMA-MMA) microcapsules.