"Diabetes mellitus has a Europe prevalence of approximately 48 million people, including approximately 1 million with Type I diabetes. Despite the availability of exogenous insulin, life expectancy and quality are still diminished by chronic or late complications of the disease. These complications can be mitigated by restoring near-normal levels of glucose. The most effective strategy to do so relies on transplanting islets from donor tissue (in the form of a whole pancreas or isolated islets). Islet transplantation has evolved as a meaningful treatment option for Type I diabetes, but its widespread application has been limited by the need for immunosuppression and limited donor tissue supply. Theoretically, this membrane serves as a mechanical barrier isolating the graft from recipient leukocytes and antibodies while continuing to allow the diffusion of glucose, water, insulin, oxygen, nutrients, and cellular waste.. This research will focus on microencapsulation of islets with functional coats in order to address many of the shortcomings associated with current techniques of immunoisolation. In this project, the technique of interfacial photopolymerization will be employed to immunoisolate islets with functional PEG hydrogel coats. Encapsulation of islets using interfacial photopolymerization is necessary to achieve higher yields to test in vivo function and immunoprotection of islets encapsulated by this method. The hypothesis is that, by employing interfacial photopolymerization along with the techniques presented in this proposal it will be possible to microencapsulate rodent and canine islets in capsules of adequate quantity and consistent quality and that the function of islets microencapsulated by this method will be equivalent to that of unencapsulated islets in environments where allogeneic and xenogenic immunologic rejection are not factors, and superior in models in which rejection is a factor."