Early-stage transplant responses in miniature-liver implants based on decellularization-recellularization technology.

Decellularization and recellularization can help address the gap between organ demand and availability. Although several whole organ engineered liver constructs have been reported, they are unable to maintain long-term function. Additionally, the effect of the early stage on cells after implantation is not described in detail. To better understand which factors affect initial cell viability, we inoculated primary hepatocytes into a miniature recellularized liver (RCL). In this study, RCL grafts based on the decellularized right lobe of a mouse were populated with 1 × 107 primary hepatocytes of rat (PRH) origin. The scaffolds exhibited spatially uniform decellularization and good collagen retention in vitro. Once repopulated and implanted into the mesentery, hepatocyte-specific function was confirmed in PRH grafts (Alb, 40 %; Hnf4a, 150 %) after 24 h, with apoptosis (Casp3) and cell-cell interaction (Tjp1) markers comparable to freshly isolated cells. Despite these positive results, we observed hypoxic conditions in the graft based on Hif1a expression, which leave room for improvement in the future. We believe that these findings will help future researchers understand the primary cell behavior of bioengineered liver constructs in vivo.