Pancreatic Islet Transplantation Technologies: State of the Art of Micro- and Macro-Encapsulation

Purpose of Review: Type 1 diabetes (T1D) is an autoimmune disease characterized by the loss of insulin-producing cells in pancreatic islets. Despite islet transplantation is effective for selected T1D patients, its widespread application is limited by islet donor shortage and the need for lifelong immunosuppression. Micro- and macro-encapsulation aimed at enveloping cells in a perm-selective biocompatible membrane can potentially eliminate these limitations. This review summarizes tissue-engineering approaches tested in preclinical models of islet transplantation, highlighting technologies currently in the clinic. Recent Findings: More than 40 years of intensive research raised promises and challenges. Ongoing clinical studies have not yet achieved the desired success as obstacles remained to be overcome: deleterious fibrotic response toward the biomaterial, poor vascularization, insufficient oxygen delivery, and recipient’s immune reaction. Summary: Only the joint effort of bioengineering, cell biology, and immunology expertises will foster the development of novel, effective, and safe technologies for insulin-producing cell transplantation. © 2017, Springer International Publishing AG.