In order to alleviate the shortage of human donors, the use of porcine islets of Langerhans for xenotransplantation in diabetic patients has been proposed as a solution. To overcome rejection, we have developed a procedure for protecting the islets by combining them with Sertoli cells and placing them in a novel subcutaneous device, that generates an autologous collagen covering. A type 1 diabetic woman was closely monitored for 10 months, and then transplanted in two devices with two months of difference and a third time after 22 months. Here we present a three-yr follow-up. The close monitoring induced a rapid decrease in exogenous insulin requirements, which stabilized between 19 and 28 IU/d for nine months. After transplantation, the requirements reduced further to below 6 IU/d and for some weeks she was insulin free. Glycosylated hemoglobin levels decreased concomitantly. Porcine insulin could be detected in the serum after a glucose challenge and insulin positive cells inside a removed device after two yr. No complications have arisen and no porcine endogenous retrovirus infection has been detected through PCR and RT-PCR. This case demonstrates the feasibility of using the xenotransplantation of porcine cells to alleviate metabolic complications and insulin requirements in type 1 diabetic patients.

The technique allowed us to obtain NPCC with optimal viability, functionality, purity, and endurance for use in research.