Xenotransplantation review : immune barriers, tissue engineering, and clinical integration

Abstract

The imbalance between the high demand for organ transplantation in humans and the insufficient organ supply makes xenotransplantation a promising technology to provide unlimited organs to patients on the waiting list and thus decrease the mortality rate. Xenotransplantation is associated with multiple immunological barriers that can result in xenograft rejection, in addition to the risk of transmitting microorganisms, such as viruses. Scientists continue to develop techniques, including immunosuppressive therapy and genetic modification, to reduce the immunogenicity of xenografts. Decellularisation techniques facilitate the clinical use of porcine heart valves. Additionally, the recellularisation using stem cells offers a new avenue for enhancing graft functionality. This review presents the current understanding of xenotransplantation and the related mechanisms in xenograft infection, discussing the progress in the genetic editing process and the latest clinical trials of pig-to-human xenotransplantation.