Establishing an effective repopulation of the endothelialized liver matrix with primary hepatocytes
Final Report Abstract
Therapeutic approaches for end-stage liver disease and acute liver failure (AFL) are limited. Currently, the only clinically established treatment options are liver support devices and liver transplantation. However, both approaches have clear limitations due to inadequate replacement of liver function and the shortage of donor organs. One experimental approach for new innovative therapy strategies is biological organ engineering. In this two-step process, an acellular matrix is generated by decellularization, which is subsequently repopulated with cells. These repopulated organs should show organ-specific function and can be used for bioartificial liver support therapies or as potential donor organs in transplantation. Especially, the repopulation process of the acellular matrix with different types of cells is still challenging. Therefore, the aim of this study was to optimize the repopulation process of the acellular graft and to investigate the function of the resulting organ in in-vitro and in-vivo experiments. To repopulate the vascular structures and the liver-specific microarchitecture of the graft, HUVEC and primary hepatocytes were applied. By developing a bioreactor with an integrated computer-controlled cell application system, the cell application process was improved and 1x1010 HUVEC and 4x108 primary hepatocytes were injected in the acellular matrix during the repopulation procedure. The HUVEC cells were applied via the portal and hepatic veins. The primary hepatocytes were only infused via the hepatic vein. The entire repopulation process took up to 16 days. Following the repopulation procedure, in-vitro and in-vivo experiments investigated the functional capacity of the graft. The in-vitro experiments demonstrated efficient ammonia detoxification by the repopulated organ over an observation period of 25 hours. Subsequently, in-vivo experiments aimed to confirm the promising in-vitro results in a preclinical ALF model. We investigated the potential application of the repopulated organ as an alternative treatment option in a porcine D-galactosamine ALF model. The extracorporeal hemoperfused repopulated organ should support the impaired liver function of the ALF pig and enable ammonia detoxification in the animal. Although the initiated therapy was performed safely, it did not significantly improve the survival of the investigated animals. In contrast to the in-vivo experiments, sufficient ammonia degradation in the in-vitro experiments was not observed. Nevertheless, these results represented a significant milestone for further investigations in biological organ engineering and suggested the principal applicability of the approach as a therapeutic alternative for ALF patients.
Publications
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Preclinical Experience of the Mayo Spheroid Reservoir Bioartificial Liver (SRBAL) in Management of Acute Liver Failure. Livers, 2(4), 387-399.
Felgendreff, Philipp; Tharwat, Mohammad; Hosseiniasl, Seyed M.; Amiot, Bruce P.; Minshew, Anna; Rmilah, Anan A. Abu; Sun, Xiaoye; Duffy, Dustin; Kremers, Walter K. & Nyberg, Scott L.
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Re-Endothelialization of Decellularized Liver Scaffolds: A Step for Bioengineered Liver Transplantation. Frontiers in Bioengineering and Biotechnology, 10 (2022, 3, 10).
Li, Kewei; Tharwat, Mohammad; Larson, Ellen L.; Felgendreff, Philipp; Hosseiniasl, Seyed M.; Rmilah, Anan Abu; Safwat, Khaled; Ross, Jeffrey J. & Nyberg, Scott L.
