CREATION OF A LUMINAL TISSUE COVERED WITH A DIFFERENTIATED UROTHELIUM FROM AUTOLOGOUS UROTHELIAL CELLS CULTURED ON FIBRIN GEL/ATELOCOLLAGEN MATRIX AFTER IMPLANTATION INTO MESENTERIUM IN RATS

Abstract

AIM: The aim of this study was to create a urothelial lining tissue made by implantation of cultured autologous urothelial cells onto mesenterium. METHODS: Cultured rat urothelial cells were seeded onto fibrin gel/atelocollagen sponge matrix and that was folded into two with the urothelial cells inside and implanted onto the mesenterium. Then, it was serially evaluated histologically. RESULTS: The implanted matrix showed cystic appearance on day 7. Stratified urothelium was observed on the luminal surface and infiltration of stromal cells and microvessels was identified in the matrix. Cystic appearance and urothelial lining remained on the day 14 and the regenerated urothelium showed the same lectinohistochemical staining as normal bladder. The infiltrated stromal cells showed positive staining to both alpha smooth muscle actin and desmin. On day 28 cystic appearance was observed in 2 of 6. On the luminal surface of the matrices with cystic appearance, urothelial lining was identified and two layers were noted within the matrices; the inner layer with a large amount of stromal cells and the outer layer with fewer stromal cells. In the matrices which lost the cystic appearance, on the contrary, urothelial lining was not identified. CONCLUSIONS: We created a mimetic urological organ covered with differentiated urothelium from cultured urothelial cells and fibrin gel/atelocollagen sponge matrix. This technique will contribute to the reconstructive surgery of the urologic organ.