The success of islet transplantation as a treatment for T1D is currently hampered by post-transplantation loss of functional islets through adverse immune and non-immune reactions. The authors aimed to test whether early islet loss can be limited and transplant survival improved by the application of nano-coatings to islets. They applied a novel coating using polysaccharides and alginates. Nano-scale encapsulated islets retained appropriate islet secretory function in the lab and were less susceptible to dying than nonencapsulated control islets. In lab experiments using a mouse transplantation model, no deleterious responses to the coatings were observed in host animals, and the transplanted encapsulated islets were effective in reversing hyperglycemia. Transplantation of the foreign, nano-coated islets resulted in preserved islet function post-implantation in five of seven mice throughout the 1-month monitoring period. It was concluded that nano-scale encapsulation offers localized immune protection for implanted islets, and may be able to limit early loss and extend survival of transplanted islets. This versatile coating scheme has the potential to be integrated with tolerance induction mechanisms, thereby achieving long-term success in islet transplantation.
Zhi ZL, Kerby A, King AJ, Jones PM, Pickup JC. Nano-scale encapsulation enhances allograft survival and function of islets transplanted in a mouse model of diabetes. Diabetologia. 2012 Apr;55(4):1081-90.
Investigators and Institutions:
This work was conducted by Dr. Pickup and his colleagues at King’s College.
Ramifications for Individuals with Type 1 Diabetes:
Encapsulation of coated islets represents a promising strategy to deliver beta cell replacement therapies without the use of chronic immunosuppression. This nano-coating concept may support a novel approach to micro-encapsulation of beta cells.
This work was not supported by JDRF.