SRS236 - Portal venous repopulation of decellularised rat liver scaffolds with syngeneic bone marrow stem cells

Abstract Liver transplantation is the only life-saving treatment for end-stage liver failure but is limited by the organ shortage and consequences of immunosuppression. Repopulation of decellularised scaffolds with recipient cells provides a theoretical solution, potentially allowing reliable and timely organ sourcing without immunosuppression. Recellularisation of the vasculature of decellularised liver scaffolds was investigated as an essential prerequisite to the survival of other parenchymal components, and with a focus on Liver Sinusoidal Cells (LSECs) given their central role in global hepatic function. Rat livers were decellularised via portal vein (PV) perfusion using a detergent-based solution. The resulting scaffolds were perfused with culture medium at 37°C and infused with primary bone marrow (BM) stem cells. BM cells were analysed for surface markers using fluorescence-activated cell sorting (FACS), and scaffold recellularisation was assessed by light (LM), electron (EM), and immunofluorescence (IF) microscopy. By day 30, scaffolds changed from translucent to opaque macroscopically. LM revealed cell engraftment in portal, sinusoidal, and hepatic vein compartments, with EM showing endothelial-like alignment. Engrafted cells expressed key LSEC endocytic receptors (mannoseR, FcR, stabilinR), and marker profiles shifted from haematopoietic (CD31− CD45+) to endothelial (CD31+ CD45−) phenotypes, confirmed by FACS and IF. This is the first report of BM stem cells used to repopulate decellularised liver. This approach is clinically relevant as the cells are recipient specific, sourceable in relevant numbers, and not subject to oncogenic concerns that relate to cell lines or induced pluripotent stem cells. These findings represent a significant step toward engineering transplantable, patient-specific neo-organs.