Successful subcutaneous pancreatic islet transplantation using an angiogenic growth factor-releasing device.

Abstract

Although the subcutaneous tissue is considered as an attractive site for pancreatic islet transplantation, the success rate has been extremely low. To use basic fibroblast growth factor (bFGF) to induce neovascularization and sufficient blood flow around the space formed for grafted islets in the subcutaneous tissue to improve the islet survival. In the experimental group, two bFGF-releasing devices were implanted bilaterally into the subcutaneous tissue (back) of diabetic Lewis rats. One week after implantation, in the same site, isolated rat islets were syngeneically transplanted after the removal of the devices. In the control group, two devices without bFGF were implanted before subcutaneous islet transplantation of the same number of islets. One week after the implantation of the bFGF-releasing devices in the experimental animals, the devices induced angiogenesis by slow release of bFGF. After transplantation of islets, the neovascularized recipient rats showed significant decreases in nonfasting blood glucose concentration and maintained normoglycemia for more than 3 months. However, in the control group, all rats failed to achieve normoglycemia after transplantation in the absence of neovascularization. This study provides evidence that the subcutaneous tissue is a promising site for pancreatic islet transplantation, which suggests the acceptability of this treatment for diabetic recipients.