Xenotransplantation of microencapsulated rat islets to treat experimental diabetes in mice

Objective To study the effects of alginate-polylysine-alginate(APA)microencapsulated islet in xenotransplantation.Methods Islets were isolated from Wistar rat pancreas by ductal rejection of collagenase,digested,and purified by using Ficoll gradient.After cultured,the islets were encapsulated in PAP semipermeable membranes.The microencapsule had a diameter ranging from 0.4 to 0.6mm with each microencapsule containing one islet. 1 000 encapsulated or non-encapsulated islets were intrapentoneally transplanted into the diabetic mice in the absence of immunosuppression.Results There was no signilicant difference in insulin Secretion between the encapsulated islets and non-encapsulated ones (P>0.05 ).Diabetes was reversed within 3 days after transplantation of encapsulated islets with the fasting plasma glucoselevels being droppedfrom(22.0±0.51)mmol/L to (7.8±0.48)mmol/L and maintaining a mean normoglycemia for 126 days. While the non-encapsulated islets only functioned less than 8 days posttransplantation Conclusion The encapsulated pancreatic islets, semipermeable membranes, can effectively prolong the xenograft survival without immunosuppression,and reverse hyperglycemia in diabetic mice. Key words: Islands of Langerhans/transplantation; Transplantation,heterologous; Diabetes mellitus,experimental; Immunologic technics