Bladder substitute reconstructed in a physiological pressure environment

Abstract

Purpose: Bladder reconstruction performed by enterocystoplasty or with bioengineered substitutes is still associated with complications, which led us to develop an autologous vesical equivalent (VE). This model has already proven its structural conformity. The challenge is to reconstruct our model in a more physiological environment, with the use of a bioreactor that mimics the dynamic of bladder filling and emptying, to acquire physiological properties.

Materials and methods: Fibroblasts and urothelial cells evolved in a three-dimensional culture to obtain a reconstructed VE. This was then cultured in our bioreactor which delivers a cyclic pressure increase up to 15 cm H(2)O, followed by a rapid decrease, to achieve a dynamically cultured VE (dcVE). To compare with the statically cultured VE, the dcVE was characterized using histology and immunofluorescence. The mechanical resistance was evaluated by uniaxial tensile tests, and the permeability level was measured with 14C-urea.

Results: Compared to our static model, the dynamic culture led to a urothelium profile like that of native bladder. Permeability analysis displayed a profile comparable to native bladder, coinciding with basal cell organization in the dcVE, while an appropriate resistance for suturing and handling was shown.

Conclusions: This new alternative method offers a promising avenue for regenerative medicine. It is distinguished by its autologous character and its efficiency as a barrier to urea. These properties could significantly reduce inflammation, necrosis, and therefore, possible rejection.