Tissue-engineered conduit using bladder acellular matrix and bladder epithelial cells for urinary diversion in rabbits

Background For muscle invasive bladder cancer, radical cystectomy is the most effective treatment now and urinary diversion is often necessary. The use of intestinal tissue for urinary diversion is frequently associated with complications. In this study, we aimed to make a tissue-engineered conduit (TEC) using bladder epithelial cells and bladder acellular matrix (BAM) for urinary diversion in rabbits. Methods Bladder epithelial cells of rabbit were cultivated and expanded in vitro , then seeded on BAM, and cultured for 7 days. Then cell-seeded graft was used to make TEC. In the experimental group, most of bladder of the rabbit was removed while bladder trigone was retained. The proximal end of TEC was anastomosed with bladder trigone and the distal end was anastomosed with the abdominal stoma. In the control group, TEC was made using unseeded BAM. Haematoxylin and eosin staining was conducted, respectively, at 1, 2, 4, and 8 weeks postoperatively. Immunohistochemistry was performed 8 weeks postoperatively. Intravenous urography, retrograde pyelography, and cystoscopy of TEC were made at 12 weeks postoperatively. Results All animals were alive in the experimental group. Haematoxylin and eosin staining showed epithelial coverage in TEC. Immunohistochemistry showed anti-cytokeratin AE 1 /AE 3 antibody and anti-ZO1 antibody positive, confirming there were mature and functional epithelial cells on the lumen of TEC. Retrograde pyelography and intravenous urography showed that TEC developed well and that there was no obstruction. In the control group, four rabbits were dead within 2 weeks and scar formation, atresia, and severe hydronephrosis were found. Conclusions We successfully made TEC using BAM and bladder epithelial cells for urinary diversion in rabbits. The lumen of this new TEC covered mature epithelial cells and could prevent urinary extravasation.