Polymeric pancreatic islet transplantation

Abstract

Pancreatic islet transplantation is one of the most promising strategies for patients suffering from diabetes mellitus, but several therapeutic immunosuppressive medications must be administered simultaneously to protect transplanted islets in the long-term. Thus, we developed chemically modified islets with a protective poly(ethylene glycol) (PEG), which reduces immunogenicity by preventing cellular immune reactions. We report here that PEG-based chemical immunoprotection can provide a effective therapy that protects transplanted islets at least for one year. However, unmodified islets (control) were completely eliminated within two weeks even when CsA was administered. On the other hand, when the islet-slab was implanted into subcutaneous site, they could cure the hyperglycemia in part. For intact islet transplantation, hyperglycemia was not controlled. These results strongly suggest that this new polymeric islet therapy provides an effective clinical means.