Engineered islet cell clusters transplanted into subcutaneous space are superior to pancreatic islets in diabetes

An alternative route for pancreatic islet transplantation is the subcutaneous space; however, inadequate vascularization in the subcutaneous space limits the availability of oxygen and nutrients to the subcutaneously transplanted islets, which leads to the development of a necrotic core in the islets, thereby causing islet dysfunction. Thus, we aimed to prevent the early apoptosis of pancreatic islets after transplantation into subcutaneous space by preparing islet clusters of appropriate size. We prepared fully functional islet cell clusters (ICCs) by using the hanging-drop technique. We optimized the size of ICCs on the basis of viability and functionality after culture in an hypoxic environment. We transplanted ICCs into the subcutaneous space of diabetic mice and evaluated the viability of the islets at the transplantation site. In an hypoxic environment, ICCs exhibited improved viability and functionality compared with control islets. ICCs, upon transplantation into the hypoxic subcutaneous space of diabetic mice, showed better glycemic control compared with control islets. Live/dead imaging of the islets after retrieval from the transplanted area revealed significantly reduced apoptosis in ICCs. Transplantation of ICCs may be an attractive strategy to prevent islet cell apoptosis that results from nonimmune-mediated physiologic stress at the transplantation site.-Pathak, S., Regmi, S., Gupta, B., Pham, T. T., Yong, C. S., Kim, J. O., Yook, S., Kim, J.-R., Park, M. H., Bae, Y. K., Jeong, J.-H. Engineered islet cell clusters transplanted into subcutaneous space are superior to pancreatic islets in diabetes.