Islets, found in the pancreas, are clusters of insulin-secreting and other cells enmeshed in tiny, specialized blood vessels. The insulin cells are killed by an autoimmune process in type 1 diabetes, which affects roughly nine million people worldwide. Although islet transplantation is a promising approach for treating such cases, the only FDA-approved method to date has significant limitations.

In a study published Jan. 29 in Science Advances, the researchers showed that special blood vessel-forming cells they developed, called “reprogrammed vascular endothelial cells” (R-VECs), can overcome some of these limitations by providing strong support for islets, allowing them to survive and reverse diabetes long-term when transplanted under the skin of mice.

“This work lays the foundation for subcutaneous islet transplants as a relatively safe and durable treatment option for type 1 diabetes,” said first author Dr. Ge Li, a postdoctoral research associate in the laboratory of senior author Dr. Shahin Rafii.