Abstract
Background: Allogeneic tissue-based therapies for Type I diabetes have demonstrated efficacy but are limited due to tissue-sourcing constraints, as the number of patients exceeds that of tissue donors. Porcine islets derived from designated pathogen-free sources could be an alternative, particularly if delivered in a way that evades the host immune system's rejection. Methods: This review focuses on approaches designed to protect xenogeneic islets from immune rejection by provision of perm-selective barriers. Results: Designated pathogen-free herds could provide a supply of wild-type porcine islets that are well tolerated when administered in a suitable protective delivery vehicle. Such barrier systems have enabled amelioration of diabetes in a variety of animal models and preliminary evidence suggests that similar results could be attained in humans. Conclusion: With advances in biomaterial design, source tissue selection, and the evolution of critical cell processing techniques, contemporary encapsulated porcine islet therapies offer a new level of clinical promise.