In an Experimental Hypospadias model to repair with tissue engineered urethral epithelium
Abstract Purpose In an experimental hypospadias model created in rabbits, to perform autologous transplantation of in vitro cultivated urethral epithelium using grafting technique and to demonstrate their survival as urethral plaque. Material and Methods We formed control and study groups, each one contained six adult male New Zealand rabbits. The hypospadias model was created by excision of approximately one cm distal urethra. Urethral mucosa was stripped off by fine dissection. In laminar air flow, mucosa was mechanically disrupted under sterile condition. Urethral epithelium was cultivated with tissue explants technique using DMEM-Ham's F 12 as medium and in 37 °C and 5 % CO2 . When they reached confluence, cells were treated with Bromodeoxyuridine (BrdU) for 24 hours, then collected following trypsinization, counted and seeded onto steril Polyglicolic asit (PGA) polymers 1x1,5 cm in size. Cells were incubated for five days. Cell-polymer complexes were laid on ventral penil surface by autologous grafting technique. In control group, cell-free polymers were used. One month later, penectomy was performed in all animals. Specimens were paraffin embedded and sections were stained with hemotoxylen and immuncytochemically for BrdU antibodies. Results In the study group, urethral epithelial cells in six grafted rabbits were stained positive for BrdU antibodies. In the control group, sections were not stained for antibodies. When sections from the study group were examined with light microscopy, almost in all sections, grated neo-urethral epithelium was detected as a regular linear cell layer. In the control group, urethral cells were seen to localize irregularly only adjacent to proximal original urethra. Conclusions In our study, we demonstrated that after in vitro propagation, urethral mucosal cells composed of grafted ventral penile surface as a regular epithelial layer. We proposed that in cases without or lack of urethral plaque, this technique can be applied as an engineered tissue.