A Novel Tissue-Engineered Liver Using Heparin-Immobilized Decellularized Liver Matrix

Orthotopic liver transplantation is the only definitive treatment for end-stage liver disease. This procedure is limited by the shortage of available donor organs. Recently, we developed methods to prepare transplantable liver grafts using decellularized whole liver that can serve as a functional alternative for donor liver transplantation. The decellularized liver matrix (DLM) is the most suitable bioscaffold for designing the tissue-engineered liver due to its fascinating characteristics including preserved extracellular microenvironment of intact liver and functional vascular structure, and ability to be repopulated with primary cells. The use of decellularized matrix accelerated engineering whole organ via recellularization with primary hepatocytes through portal vein perfusion and exhibited preservation and enhancement of liver-specific phenotypes of the engineered liver graft. The predominant obstacle for engineered liver transplantation is thrombogenicity that induces platelet activation and ultimately hinders the delivery of nutrients and oxygen within the entire engineered tissue mass. In this study, we fabricated heparin-immobilized decellularized matrices that can prevent thrombosis and improve the survival of the graft in vivo. The thromboresistant surface modification of the acellular three-dimensional scaffold was achieved via layer-by-layer self-assembly and was optimized through ex vivo diluted blood perfusion. Preliminary results showed that only heparin-immobilized decellularized matrices exhibited even and positive staining for toluidine blue over the entire biocaffold as compared to control, and prevented thrombus formation during ex vivo blood perfusion. The heparin-immobilized DLM will be utilized to recellularize the scaffold with primary hepatocytes to generate functional liver grafts that can be used as a favorable replacement for liver transplantation.