Conformal coating process refinement and materials optimization improves the insulin secretion of encapsulated islets

Statement of Purpose. Type 1 diabetes (T1D) results in the T cell-mediated destruction of the insulin-producing β cells in the pancreas. β cell replacement by way of donor islet transplantation would allay the problems associated with the disease but requires systemic immunosuppression for graft function and survival. Due to immune suppression, islet transplantation is only indicated for a fraction of patients with T1D. Islet encapsulation strives to protect the donor tissue by preventing direct contact with host immune cells. While such strategies have exhibited safety in clinical trials, long-term efficacy remains a lofty goal that is subverted by the large graft volumes, limited access to well vascularized sites, and increased barrier to diffusion associated with traditional microencapsulation. Conformal coating minimizes capsule thickness and graft volume, representing the next generation of encapsulated islet products (Fig. 1). Here, we hypothesize that the post-conformal coating viability and glucose-stimulated insulin secretion (GSIS) performance of islets may be increased by optimizing process parameters, materials, and recovery procedures associate with this platform.