A novel bioscaffold with naturally-occurring extracellular matrix promotes hepatocyte survival and vessel patency in mouse models of heterologous transplantation

Background: Naive decellularized liver scaffold (nDLS)-based tissue engineering has been impaired by the lack of a suitable extracellular matrix (ECM) to provide active micro-environmental support. Aim: The present study aimed to examine whether a novel, regenerative DLS (rDLS) with an active ECM improves primary hepatocyte survival and prevents thrombosis. Methods: rDLS was obtained from a 30-55% partial hepatectomy that was maintained in vivo for 3-5 days and then perfused with detergent in vitro. Compared to nDLS generated from normal livers, rDLS possesses bioactive molecules due to the regenerative period in vivo. Primary mouse hepatocyte survival was evaluated by staining for Ki-67 and Trypan blue exclusion. Thrombosis was assessed by immunohistochemistry and ex vivo diluted whole-blood perfusion. Hemocompatibility was determined by near-infrared laser-Doppler flowmetry and heterotopic transplantation. Results: After recellularization, rDLS contained more Ki-67-positive primary hepatocytes than nDLS. rDLS had a higher oxygen saturation and blood flow velocity and a lower expression of integrin alpha IIb and alpha 4 than nDLS. Tumor necrosis factor-alpha, hepatocyte growth factor, interleukin-10, interleukin-6 and interleukin-1 beta were highly expressed throughout the rDLS, whereas expression of collagen-I, collagen-IV and thrombopoietin were lower in rDLS than in nDLS. Improved blood vessel patency was observed in rDLS both in vitro and in vivo. The results in mice were confirmed in large animals (pigs). Conclusion: rDLS is an effective DLS with an active microenvironment that supports primary hepatocyte survival and promotes blood vessel patency. This is the first study to demonstrate a rDLS with a blood microvessel network that promotes hepatocyte survival and resists thrombosis. (C) 2018 Elsevier Ltd. All rights reserved.