Successful Allotransplantation of Encapsulated Islets in Pancreatectomized Canines for Diabetic Management Without the Use of Immunosuppression

Abstract

Pancreatic islet transplantation has shown great success in the treatment of diabetic patients. However, the required immunosuppressive therapy exposes patients to serious side effects. We have designed a novel five-component/three-membrane capsule and encapsulation system to protect the transplanted islet cells from immune system attack while allowing the influx of molecules and nutrients necessary for cell function/survival and efflux of the desired cellular product, specifically insulin, for making recipients healthy. We transplanted encapsulated canine pancreatic islets into the peritoneal cavity of pancreatectomized canines. Transplantation normalized fasting blood glucose levels in nine out of nine dogs for up to 214 days with a single transplantation. Retransplantation was assessed in three animals and encapsulated islets were effective in providing fasting glycemic control after the initial transplantation had run its course. No immunosuppression or anti-inflammatory therapy was used. This advancement in transplantation may lead to an alternative approach for islet transplantation treatment for diabetic patients. This approach may also benefit patients suffering from other hormone deficiency diseases including liver disease and Parkinson's disease.