ABSTRACT
BACKGROUND:Colagen hydrogel provides good matrix support for hepatocyte growth and tissue reconstruction, and the colagen-based engineered tissue is easy to merge the growth and form integrated tissue. OBJECTIVE:To improve the thickness of engineered hepatic tissue by dissociating hepatocytes/colagen hydrogel composite into smal hepatic units that accumulate in the subcutaneous cavity. METHODS:Freshly isolated hepatocytes from rats were mixed with colagen hydrogel to establish hepatocytes/colagen hydrogel composite. The hepatocytes/colagen hydrogel composite was dissociated into smal hepatic units after being cured. The undissociated hepatocytes/colagen hydrogel composite was taken as a control. Six Spraque-Dawley rats were enroled. Three of them were subjected to a two-thirds partial hepatectomy to induce liver regeneration. Dissociated and undissociated hepatocytes/colagen hydrogel composites were implanted into the bilateral inguinal subcutaneous cavity. Dissociated and undissociated hepatocytes/colagen hydrogel composites were implanted into the bilateral inguinal subcutaneous cavity of the other three rats. At the 7th day after transplantation, engineered hepatic tissue formation was evaluated using hematoxylin-eosin staining, immunohistochemical staining and India ink perfusion methods. RESULTS AND CONCLUSION:The grafts in these two groups al formed vascular engineered hepatic tissue in the subcutaneous cavity, but after the smal hepatic units merged, a large piece of vascular engineered hepatic tissue formed. The hepatic tissue thickness was up to 4 mm. The whole piece of implanted liver grafts only formed smal pieces of hepatic tissues, with only several layers of cels. Immunohistochemistry staining confirmed that the hepatocytes in vascular engineered hepatic tissue had the characteristics and functions of natural hepatocytes. Partial hepatectomy experiment showed that engineered hepatic tissue had the ability to respond to regenerative stimulus of partial hepatectomy. These results show that dissociating the hepatocytes/colagen hydrogel grafts into smal units that accumlate in the subcutaneous cavity can increase the thickness of the engineered hepatic tissue.