title: Two-layer tissue engineered urethra using oral epithelial and muscle derived cells.
abstract: OBJECTIVE
  We fabricated novel tissue engineered urethral grafts using autologously harvested oral cells. We report their viability in a canine model.
  
  
  METHODS
  Oral tissues were harvested by punch biopsy and divided into mucosal and muscle sections. Epithelial cells from mucosal sections were cultured as epithelial cell sheets. Simultaneously muscle derived cells were seeded on collagen mesh matrices to form muscle cell sheets. At 2 weeks the sheets were joined and tubularized to form 2-layer tissue engineered urethras, which were autologously grafted to surgically induced urethral defects in 10 dogs in the experimental group. Tissue engineered grafts were not applied to the induced urethral defect in control dogs. The dogs were followed 12 weeks postoperatively. Urethrogram and histological examination were done to evaluate the grafting outcome.
  
  
  RESULTS
  We successfully fabricated 2-layer tissue engineered urethras in vitro and transplanted them in dogs in the experimental group. The 12-week complication-free rate was significantly higher in the experimental group than in controls. Urethrogram confirmed urethral patency without stricture in the complication-free group at 12 weeks. Histologically urethras in the transplant group showed a stratified epithelial layer overlying well differentiated submucosa. In contrast, urethras in controls showed severe fibrosis without epithelial layer formation.
  
  
  CONCLUSIONS
  Two-layer tissue engineered urethras were engineered using cells harvested by minimally invasive oral punch biopsy. Results suggest that this technique can encourage regeneration of a functional urethra.
authors.affiliation: Department of Urology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mikami
authors.forename: Go
authors.initials: G
authors.lastname: Kuwahara
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Nakamura
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamato
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Tanaka
authors.forename: Shohta
authors.initials: S
authors.lastname: Kodama
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004285:Dogs; D004847:Epithelial Cells; D007150:Immunohistochemistry; D008297:Male; D009061:Mouth Mucosa / Q000166:cytology*; D009130:Muscle, Smooth / Q000166:cytology*; D009924:Organ Culture Techniques; D023822:Tissue Engineering / Q000379:methods*; D020858:Tissue and Organ Harvesting; D014521:Urethra / Q000637:transplantation*