title: Urethral reconstruction with tissue-engineered human amniotic scaffold in rabbit urethral injury models.
abstract: BACKGROUND
  Mitigating urethral injury remains a great challenge for urologists due to lack of ideal biomaterials for urethroplasty. The application of amniotic membranes (AM) over other synthetic materials make it a better potential source for urethral reconstruction. We separated the basement layer of AM to obtain denuded human amniotic scaffold (dHAS) and then inoculated primary rabbit urethral epithelial cells on the surface of dHAS to define whether this strategy minimize potential rejection and maximize the biocompatibility of human AM.
  
  
  METHODS
  After the successful acquisition of dHAS from AM, cell-seeded dHAS were prepared and characterized. Both cell-seeded dHAS and acellular dHAS were subcutaneously implanted. Immune responses were compared by histological evaluation and CD4 cell and CD8 cell infiltrations. Then they were applied as urethroplastic materials in the rabbit models of urethral injury to fully explore the feasibility and efficacy of tissue-engineered dHAS xenografts in urethral substitution application.
  
  
  RESULTS
  Mild inflammatory infiltration was observed in cell-seeded dHAS grafts, as revealed by fewer accumulations of CD4 cells and CD8 cells (or neutrophils or other immune cells). Urethral defects of rabbits in the urethroplastic group with dHAS implantation (n=6) were completely resolved in one month, while there were one infection and one fistula in the control group with acellular dHAS patches (n=6). Histopathological analysis revealed mild immune response in cell-seeded dHAS group (P<0.05).
  
  
  CONCLUSIONS
  Tissue-engineered dHAS minimize potential rejection and maximize the biocompatibility of AM, which makes it a potential ideal xenograft for urethral reconstruction.
authors.affiliation: Department of Urology, Xijing Hospital, Fourth Military Medical University, Xi'an, China (mainland).
authors.forename: Fuli
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Biomedical Engineering, Fourth Military Medical University, Xi'an, China (mainland).
authors.forename: Tao
authors.initials: T
authors.lastname: Liu
authors.affiliation: Department of Urology, Xijing Hospital, Fourth Military Medical University, Xi'an, China (mainland).
authors.forename: Lijun
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Urology, Xijing Hospital, Fourth Military Medical University, Xi'an, China (mainland).
authors.forename: Geng
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Department of Urology, Xijing Hospital, Fourth Military Medical University, Xi'an, China (mainland).
authors.forename: Heliang
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Urology, Xijing Hospital, Fourth Military Medical University, Xi'an, China (mainland).
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Yi
authors.affiliation: Department of Urology, Xijing Hospital, Fourth Military Medical University, Xi'an, China (mainland).
authors.forename: Xiaojian
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Internal Medicine, University of California - Davis, Sacramento, USA.
authors.forename: Tzu-yin
authors.initials: TY
authors.lastname: Lin
authors.affiliation: Department of Urology, Xijing Hospital, Fourth Military Medical University, Xi'an, China (mainland).
authors.forename: Weijun
authors.initials: W
authors.lastname: Qin
authors.affiliation: Department of Urology, Xijing Hospital, Fourth Military Medical University, Xi'an, China (mainland).
authors.forename: Jianlin
authors.initials: J
authors.lastname: Yuan
mesh_terms: D000650:Amnion / Q000637:transplantation / Q000648:ultrastructure; D000818:Animals; D018920:Coculture Techniques; D004195:Disease Models, Animal; D004847:Epithelial Cells / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D011817:Rabbits; D019651:Plastic Surgery Procedures / Q000379:methods*; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*; D014521:Urethra / Q000293:injuries* / Q000601:surgery*