BACKGROUND:Biological artificial skin made by fibroin, connective tissues, biopolymer materials, synthetic polymeric material, nano materials as wel as sensor and non-biological artificial skin both have achieved satisfactory effects in clinical trials, but there is stil a significant difference from the natural skin. OBJECTIVE:To investigate the treatment outcomes of epidermal stem cel s/porcine acel ular dermal tissue-engineered skin for ful-thickness skin defects in rats. METHODS:Twenty Sprague-Dawley rats were selected to make the skin defect model on the rat back, and then randomly divided into experimental and control groups, fol owed by subjected to the implantation of human epidermal stem cel s/porcine acel ular dermal tissue-engineered skin and porcine acel ular dermal matrix, respectively. Gross, histological and immunohistochemical observations were performed at 4 weeks after implantation.RESULTS AND CONCLUSION:Gross observation:the wound in the experimental group healed wel , and the skin had good elasticity;the control group showed scar formation in the implanted site and the texture was hard. Histological observation:there were good epidermal and dermal structures under microscope in both groups, and the basal layer, stratum corneum and stratum corneum of the epidermis could be distinguished clearly. Compared with the experimental group, more fibrous connective tissue could be found in the control group. Immunohistochemical observation:the wound surface in the experimental group was positive for the anti-HLA class I antigen, while the wound surface in the control group negative for the anti-HLA class I antigen. These findings suggest that the human epidermal stem cel s/porcine acel ular dermal tissue-engineered skin can effectively inhibit the scar formation and contracture in the repair of ful-thickness skin defects.

The launch of direct-acting antiviral agents is a milestone in the treatment of hepatitis C, but further studies are needed to explore its specific timing and effectiveness in liver transplantation for HCV-related hepatocellular carcinoma (HCC). This article summarizes related guidelines, consensus statements, and recommendations in China and globally and the advantages of different treatment timing strategies. Furthermore, a retrospective analysis of related studies is performed to investigate the controversial topic of the impact of direct-acting antiviral agents on the recurrence rate of HCV-related HCC after liver transplantation, and it is pointed that direct-acting antiviral agents can reduce the risk of HCC recurrence in liver transplant recipients with HCV-related HCC. The selection of treatment timing should consider various factors such as liver function, waiting time for donors, and utilization of HCV-positive organs.