Tissue-engineered buccal mucosa for substitution urethroplasty

OBJECTIVE To develop tissue-engineered buccal mucosa (TEBM) for use in substitution urethroplasty, as urethral reconstruction is limited by the amount and type of tissue that is available for grafting, and BM has become the favoured tissue for use as a urethral substitute in the last decade. MATERIALS AND METHODS After enzymatic treatment of a small (0.5 cm) BM biopsy the epidermis and dermis were mechanically separated. Oral keratinocytes were isolated from the epidermis and oral fibroblasts from the dermis. These cells were expanded and applied to sterilized de-epidermized dermis (DED) to obtain a full-thickness TE oral mucosa. Horizontal migration of keratinocytes on the DED was assessed using a tetrazolium-blue (MTT) assay. The TEBM was assessed histologically after mechanical stressing in vitro using catheterization and meshing. RESULTS Histologically the TEBM closely resembled the native oral mucosa after culturing at an air-liquid interface for 2 weeks. The MTT assay showed good horizontal migration of keratinocytes on the DED. Serial histology revealed a gradually increasing thickness of the epidermis and remodelling of the dermis by the fibroblasts from day 1 to day 14. Despite subjecting the TEBM to mechanical stress the integrity of the epidermal-dermal junction was maintained. CONCLUSIONS We report the successful culture of full-thickness TEBM for substitution urethroplasty, which is robust and suitable for clinical use.