Fusion of blood vessel organoids with human pancreatic islets improves insulin response over time

Pancreatic islet transplantation is a promising treatment strategy for type 1 diabetes, however there are still major challenges to overcome, including vascularization. Novel strategies for the generation of prevascularized islets with native microvessels have reported improved islet functionality, vascularization and engraftment emphasizing integral role of microvascular bed. Recently a new model of self-organizing three-dimensional human blood vessel organoids (BVOs) has been developed from human pluripotent stem cells (hPSCs), composed of both endothelial and mural cells. BVO recapitulate key features of human microvasculature such as formation of vascular network, vascular lumen and basement membrane, and have been shown to be perfusable. Here, we report a new strategy to construct prevascularized islets by fusion with hPSC-derived BVOs. We demonstrate that islets and BVOs in co-culture leads to fusion and improved insulin secretion over time, on two independent human islet donors, suggesting a new therapeutic approach for pancreatic islet transplantation and type 1 diabetes modeling.