ACELLULAR LIVER SCAFFOLD PROMOTES CELL RECRUITMENT AFTER HETEROTOPIC TRANSPLANTATION

Background Liver tissue engineering is a promising tool to solve the shortage of organs. In this context, acellular liver scaffolds (ALS) obtained by decellularization are an attractive substrate to organ transplantation. However, the cell recruitment proprieties after in vivo transplantation (Tx) remain unclear. Objective To address this issue, we aimed to investigate the ALS in vivo cell recruitment proprieties after heterotopic auxiliary liver transplantation in rats. Methods Donor Wistar rats (n=4) were submitted to a surgical procedure to promote liver procurement. For decellularization, the livers were perfused through the portal vein (PV) using an infusion pump at 3 ml/min with water for 2 hours followed by 1% Triton X-100 for 2 hours and SDS 1% for 18-24h. After decellularization, livers were washed with water for 2 days and submitted to DNA quantification and histology analysis (H&E and Sirius red). Then, to transplant ALS, recipient rats (n=3) were submitted to a surgical procedure to remove the left-side kidney. The PV and inferior vena cava of the ALS were anastomosed to the recipient rats’ left arterial and renal vein respectively. Recipients rat serum biochemical analysis (ALB- albumin) was measured before and post-Tx. H&E, Periodic acid–Schiff, TUNEL and, immunohistochemistry (Ki67, Superoxide dismutase-SOD, Catalase-CAT, Glutathione-peroxidase-GPX) analyzes were performed to evaluate ALS post-Tx. Data were expressed as mean ± SD and all quantitative parameters were analyzed using Student's t-test. Results DNA quantification analysis showed a significant reduction (1813.8±125.6 to 19.2±8,03 ng DNA/mg dry weight) and H&E staining showed that the decellularization process removed the cells and preserves the structure and components of the ALS. Active blood flow within the ALS was observed indicating that the vessels were able to sustain the arterial blood pressure when the circulation was re-established. H&E analysis revealed that ALS was able to promote cell recruitment and to allow migration and distribution of Ki67, SOD, CAT and, GPX positive cells in whole ALS parenchyma 2 hours post-Tx. Also, no glycogen storage was observed into ALS 2h post-Tx. ALB serum analysis showed no adverse impact on recipient rat biochemical parameters (2.17±0.05 vs.1.8± 1.11). Conclusion In conclusion, ALS is a promising approach to liver transplantation able to promote various cell type recruitment, distribution, and whole recellularization in vivo.