AN ENCAPSULATION SYSTEM FOR THE IMMUNOISOLATION OF PANCREATIC-ISLETS

Over a thousand combinations of polyanions and polycations were tested to search for new polymer candidates that would be suitable for encap sulation of living cells. The combination of sodium alginate, cellulos e sulfate, poly (methylene-co-guanidine) hydrochloride, calcium chlori de, and sodium chloride was most promising. In parallel, a novel multi loop chamber reactor was developed to control the time of complex form ation and to negate gravitational effects such as pancreatic islet sed imentation and droplet deformation during the encapsulation process. E ncapsulated rat islets demonstrated glucose-stimulated insulin secreti on in vitro, and reversed diabetes in mice. This new capsule formulati on and encapsulation system allows independent adjustments of capsule size, wall thickness, mechanical strength, and permeability, which may offer distinct advantages for immunoisolating cells.