VITRIFICATION OF GENETICALLY-ENGINEERED ISLETS

Transplantation of pancreatic islets for the treatment of diabetes mellitus is widely anticipated to eventually provide a cure once a means for preventing rejection is found without reliance upon global immunosuppression. Long-term storage of islets is crucial for the organization of transplantation, islet banking, tissue matching, organ sharing, immuno-manipulation and multiple donor transplantation. Existing methods of cryopreservation involving freezing are known to be suboptimal providing only about 50% survival. The development of techniques for ice-free cryopreservation of mammalian tissues using both natural and synthetic ice blocking molecules, and the process of vitrification (formation of a glass as opposed to crystalline ice) has been a focus of research for Organ Recovery Systems during recent years. These approaches have established in other tissues that vitrification can markedly improve survival by circumventing ice-induced injury. The aim of this Phase I study is to apply these new technologies to the long- term storage of pancreatic islets. The study is designed to optimize both the pre-vitrification hypothermic shipping conditions using newly developed media and to compare new proprietary techniques for ice- free cryopreservation with conventional freezing protocols. Optimized techniques will then be applied to genetically-modified islets designed to overcome immune responses in the diabetic host in Phase II. PROPOSED COMMERCIAL APPLICATIONS: The ultimate aim of this project is to develop a marketable package comprising cryopreserved genetically-modified islets that can be removed from vitrified storage, rewarmed simply without specialist training or equipment, and transplanted to produce a well tolerated graft with biological effectiveness that exceeds that of insulin injection therapy.