Matrix testing for urothelial tissue engineering

Introduction: Surgical reconstruction of the bladder is associated with many well-known complications. Tissue engineering is under discussion as a potential therapeutic strategy and many of the proposed benefits are of special interest for children. Biomaterials play a key role in tissue engineering. Many materials have been proposed for the experimental reconstruction of the bladder and urethra. They determine the biological and mechanical characteristics of the reconstructed tissues. Most publications focus on a single material. In order to identify the most suitable biomaterial it was the aim of this study to compare biological and mechanical features of different biomaterials seeded with urothelial cells in vitro. Materials and Methods: Commercially available biomaterials (Biogide®, Ethisorb®, Lyoplant®, SIS®, Vicryl®, Xenoderm®) of biologic or synthetic origin were seeded with urothelial cells. Cell-matrix constructs were cultured and investigated by scanning electron microscopy for surface structure and cell morphology. They were also subjected to extension until failure and the force required was reported as f_max. Values obtained and curve shape were compared to specimens of bladder mucosa and submucosa. Results: Cell adhesion and morphology showed marked differences between materials. Cell shape varied from single spherical cells to confluent layers of flat urothelium. f_max ranged from 0.02 N to 48.86 N for tested materials and 1.19 N for native bladder mucosa/submucosa. Discussion: The materials showed marked differences in biological and mechanical features in vitro. Cells cultured on biogenic matrices were more similar to native urothelium. Most of the tested materials showed different curve shapes and higher f_max values than native bladder mucosa.