The mechanisms underlying early failure of islet transplants are not entirely clear, but are thought to be related to delayed blood vessel growth in the new islets. In addition to their nutritional and gas exchange role, it was thought that blood vessels play an active role in cell-cell communications, a key requirement supporting islet survival and engraftment. To test this concept the authors developed three dimensional blood vessel networks in engineered pancreatic tissues. The experimental setup closely mimics the natural anatomical context of pancreatic vasculature. Enhanced islet survival correlating with formation of functional tube-like blood vessels was demonstrated. Addition of cells that make up connective tissue promoted blood vessel-like structure formation, which further supported islet survival as well as insulin secretion. Implantation of prevascularized islets into diabetic mice promoted the survival, integration and functioning of the transplanted engineered tissue, supporting the suggested role of blood vessels in islet survival. These findings present potential strategies for preparation of transplantable islets with increased survival prospects and insights for improving the success of islet encapsulation products.
Engineered vascular beds provide key signals to pancreatic hormone-producing cells. PLoS One. 2012;7(7):e40741.
Investigators and Institutions:
The study was led by Dr. Levenberg and her colleagues at Technion – Israel Institute of Technology.
Ramifications for Individuals with Type 1 Diabetes:
Islet transplantation has been shown to have great efficacy in T1D individuals, but have limited availability. This research shows a critical factor in transplantation that can improve transplantation outcome and may improve the success of future islet encapsulation products.
This work was supported in part by JDRF.