Cell replacement and regeneration therapy for diabetes.

Reduction of beta cell function and a beta cell mass is observed in both type 1 and type 2 diabetes. Therefore, restoration of this deficiency might be a therapeutic option for treatment of diabetes. Islet transplantation has benefits, such as reduced incidence of hypoglycemia and achievement of insulin independence. However, the major drawback is an insufficient supply of islet donors. Transplantation of cells differentiated in vitro or in vivo regeneration of insulin-producing cells are possible approaches for beta cell/islet regenerative therapy. Embryonic and adult stem cells, pancreatic ductal progenitor cells, acinar cells, and other endocrine cells have been shown to differentiate into pancreatic beta cells. Formation of fully functional beta cells and the safety of these cells are critical issues for successful clinical application.