title: [Construction of tissue-engineered urothelial tissue in vitro and in vivo with bladder acellular matrix as scaffold].
abstract: OBJECTIVE
  To investigate the construction of urothelial structure by tissue engineering.
  
  
  METHODS
  Fresh bladder of New Zealand white rabbits were processed to prepare the bladder acellular matrix graft (BAMG) as the scaffold, which was evaluated by Masson's trichrome staining and the scanning electronic microscope. Bladder epithelia were obtained by enzymatic digestion and were proliferated in vitro. Growth of cells was observed under the inverted phase contrast microscope, and cells were identified by immunohistochemical method. The bladder epithelia were seeded on BAMG, and the epithelia/BAMG composites were observed by HE staining and the scanning electronic microscope. The composites fabricated in vitro were implanted into nude rats, and were retrieved in 4 and 8 weeks, which were observed by general observation, histological and immunohistochemical method.
  
  
  RESULTS
  White semi-transparent membrane appeared in the prepared BAMG, and a fibre mesh structure of the material without residual cells was observed under the scanning electronic microscope. Bladder epithelia cultured in vitro showed a paving stone structure. Immunohistochemical staining with cytokeratin was performed, and brown cellular plasma staining was observed as positive reaction. After the epithelia were seeded on BAMG in vitro for 7 days, the cells fully covered the surface of the framework, showing a single-layer cellular structure. After being implanted into nude rats for 4 weeks and 8 weeks, the epithelia seeded on the BAMG formed a multi-layer structure.
  
  
  CONCLUSIONS
  Urothelial structures can be constructed in vitro and in vivo by tissue engineering, which lays a technical foundation for further tissue engineered urinary tract reconstruction experiments.
authors.affiliation: Department of Urology, West China Hospital, Sichuan University, Chengdu 610041, China. scuhp@163.com
authors.forename: Ping
authors.initials: P
authors.lastname: Han
authors.forename: Chao
authors.initials: C
authors.lastname: Song
authors.forename: Yu-ru
authors.initials: YR
authors.lastname: Yang
authors.forename: Kun-jie
authors.initials: KJ
authors.lastname: Wang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wei
authors.forename: Hong
authors.initials: H
authors.lastname: Li
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D005109:Extracellular Matrix; D011817:Rabbits; D051381:Rats; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds; D001743:Urinary Bladder / Q000166:cytology*; D019459:Urothelium