Diabetes affects 11,000 people in America and 60,000 new cases are diagnosed every year. The transplantation of encapsulated, immunoprotected islets as a treatment has recently generated much interest. The minute-to-minute regulation of glucose achievable by this technique is not possible by conventional therapeutic techniques and is the major cause of the morbidity of diabetes. We have developed a novel alginate material for islet encapsulation that is nontoxic, noninflammatory and is stable in vivo for the long-term. The material is photocrosslinkable in addition to its inherent ionic crosslinkability. This allows for a single-step, rapid encapsulation process while previous methods required multiple steps and relatively long periods for efficient encapsulation. We have been able to reverse diabetes for almost 300 days in mice receiving encapsulated rat islets with this material. In the Phase I study we propose to perform encapsulation and transplant of pig islets into spontaneously diabetic dogs to test the feasibility of this technique in the xenotransplant model. In addition acute material toxicity and mutagenicity analysis will be performed. In Phase II we propose to obtain additional safely and efficacy data in dogs and obtain FDA approval to begin clinical trials of the procedure in humans. Pig islets will be utilized in the study due to the potential unlimited availability of pig pancreata from herds that will be specially bred for this commercial purpose.National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
