Tissue-engineered tubular grafts constructed with stem cells and bladder acellular matrix in long-segmental ureteral reconstruction / 中国组织工程研究

ABSTRACT

BACKGROUND:The main way for long-segmental ureteral reconstruction may cause a lot of traumas and complications. Therefore, to seek a new repair method is urgent. OBJECTIVE:To investigate the feasibility of a tissue-engineered tubular graft for ureteral reconstruction. METHODS:Bone marrow mesenchymal stem cels and smooth muscle cels of rabbits were seeded into the two surfaces of bladder acelular matrix and cultivated for 7 days. Then the graft was used to prepare a 4-cm long tissue-engineered tubular graft, which was regarded as experimental group. Smooth muscle cels seeded onto the bladder acelular matrix was used to construct the tissue-engineered tubular graft as control group. Twenty-five New Zealand rabbits were randomly divided into experimental group (n=20) and control group (n=5), and two kinds of tubular grafts covered with omentum were implanted into the two groups, respectively, for repair of ureteral defects. Hematoxylin-eosin staining and immunohistochemical detection were performed at 2, 4, 8 weeks after implantation. RESULTS AND CONCLUSION:In the experimental group, hematoxylin-eosin staining showed epithelial coverage and muscle fibers on the lumen of tissue-engineered tubular grafts at 8 weeks after implantation; immunohistochemistry showed that anti-AE1/AE3 antibody and anti-uroplakinⅢa antibody were positive, confirming that there were mature epithelial cels on the lumen of tissue-engineered tubular grafts. In the control group, five rabbits were dead within 2 weeks after removal of ureteral scaffold, and autopsy showed scar formation inside the graft and severe hydronephrosis. These results demonstrate that it is feasible to construct the tissue-engineered tubular graft using bone marrow mesenchymal stem cels and smooth muscle cels into the bladder acelular matrix for ureteral reconstruction. Bone marrow mesenchymal stem cels can potentialy promote urothelial regeneration.