Cell-Based and Cell-Derived Therapies Delivered During Ex Vivo Machine Perfusion for Solid Organ Reconditioning Prior to Transplantation: A Systematic Review

Background/Objectives: Organ shortage is a major barrier to transplantation, leading to the emergence of marginal donor organs and extended criteria donor grafts and, alongside these, machine perfusion as a platform for reconditioning grafts to meet transplantation standards. Despite functioning as a reconditioning platform in its own right, machine perfusion also allows for the delivery of therapeutic agents directly to grafts prior to transplant. Cell-based and cell-derived therapies have been increasingly explored for delivery during this window, although evidence is fragmented across individual organ systems, and whether ex vivo benefit is confirmed post-transplant remains unclear. This systematic review aimed to synthesise the evidence from both perfusion-phase findings and post-transplant findings across solid organ machine perfusion, evaluating the concordance between the two.