Urothelium Tissue Engineering Using Biopsies From Transurethral Resection of Prostate

Bladder biopsies will be obtained during cystoscopy, conserved in culture medium (DMEM®), digested by dispase and sowed on collagen-coated culture support. Keratinocyte Serum Free Medium (KSFM) will be used for proliferation. Microscopy, immunohistochemistry, RNA extraction, Reverse Transcription and quantitative Polymerase Chain Reaction (RT-qPCR) will be performed during passages. Cell culture conditions will be optimized to improve proliferation and avoid loss of differentiation. The investigators will develop scaffolds based on sodium alginate hydrogels, followed by freeze-drying to generate porous sponges (at -20°C and -80°C). Cultured cells will be associated to these original scaffolds and to other scaffolds, for example alginate hydrogels or Collagen Cell Carrier (CCC), cultivated for 28 days and analyzed. Histological and immunohistological appearance of cellularized scaffolds will be compared to assess the effectiveness of each scaffold for tissue engineering in urothelium. Cellularized scaffolds will be studied in vitro (Transepithelial Electrical Resistance, impermeability, ability to be stitched, resistance to urine) and in vivo in ectopic location (subcutaneous location in Nude mice) or in orthotopic location (bladder augmentation in small animal).