A Novel and Faster Method to Obtain a Differentiated 3-Dimensional Tissue Engineered Bladder

PurposeWe report what is to our knowledge a novel approach that led to the rapid development of a 3-dimensional bladder model, including a differentiated urothelium reconstructed without a period of exposure to the air-liquid interface.Materials and MethodsBilayered bladder constructs were produced using anchored mesenchymal cell seeded collagen gels to create the mesenchymal layer. Gels were coated with urine for 20 minutes before urothelial cell seeding. The 3-dimensional bladder models were cultured under submerged conditions for 15 days.ResultsPure urine coating of the collagen matrix surface combined with its intermittent presence during urothelial development was found to be best to maintain urothelial cell properties. Immunohistological and ultrastructural analyses showed the formation of a pseudostratified urothelium devoid of abnormal K14 expression, allowing for uroplakin trafficking and forming an asymmetrical unit membrane at the apical surface.ConclusionsSuch tissues could be adapted for clinical applications, including bladder repair. In the context of basic science this model could serve as a good alternative to animal use for fundamental and pharmacological studies of normal or pathological bladder tissues.