Immunoisolation of xenogeneic islets using a living tissue engineered cartilage barrier

Abstract

HIS STUDY demonstrates in vivo survival of islets of Langerhans within a capsule of chondrocytes, which may serve as an immunoisolation barrier using the immunoprivileged properties of the chondrocyte matrix. Previous in vitro studies have shown that the glucose/insulin feedback mechanism of the encapsulated islets remains intact and that the chondrocyte capsule permits diffusion of glucose and insulin.’ Islet transplantation is a potential cure for diabetes mellitus. One major problem remains the necessity of immunosuppression. One experimental strategy to prevent rejection is immunoisolation. Current methods of immunoisolation use artificial materials as barrier devices.’ These materials are not completely inert and can induce a foreign body and inflammatory reaction. The resulting fibrous tissue overgrowth diminishes the diffusion properties. Stimulated macrophages secrete nitric oxide which penetrates the barriers and destroys the encapsulated islets.3 We propose the encapsulation of islets of Langerhans with a layer of autologous chondrocytes to prevent immunorecognition and destruction of allogeneic or xenogeneic islets.