title: Tissue engineering for regeneration of the tracheal epithelium.
abstract: OBJECTIVE
  The slowness of epithelialization on the artificial trachea that has been successfully used in humans is a problem. The purpose of this study was to develop a way to regenerate the epithelium on the surface of this artificial trachea.
  
  
  METHODS
  In an in vitro study, isolated rat tracheal epithelial cells were seeded on a collagenous gel that was stratified on a collagenous sponge. Histologic and immunohistochemical examinations were made. In an in vivo study, we transplanted grafts with green fluorescent protein-positive tracheal epithelial cells onto the tracheal defects of normal rats. At 3, 7, 14, and 30 days after the operation, histologic and immunohistochemical examinations were made.
  
  
  RESULTS
  In the in vitro study, the 3 layers--the epithelium, gel, and sponge--could be observed. The epithelium expressed cytokeratin 14, cytokeratin 18, and occludin. In the in vivo study, the artificial trachea was covered with epithelium at 3 days after operation, and then the epithelium differentiated from single- or double-stratified squamous epithelium into columnar ciliated epithelium. Green fluorescent protein-positive cells were found 3 days after operation.
  
  
  CONCLUSIONS
  We believe that the method used in our experiment is an effective way to regenerate the epithelium on the surface of an artificial trachea. With further experimentation, this method should be suitable for clinical application.
authors.affiliation: Department of Otolaryngology, School of Medicine, Fukushima Medical University, 1 Hikarigaoka, Fukushima City 960-1295, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Nomoto
authors.forename: Teruhisa
authors.initials: T
authors.lastname: Suzuki
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Tada
authors.forename: Ken
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Masao
authors.initials: M
authors.lastname: Miyake
authors.forename: Akihiro
authors.initials: A
authors.lastname: Hazama
authors.forename: Ikuo
authors.initials: I
authors.lastname: Wada
authors.forename: Shinichi
authors.initials: S
authors.lastname: Kanemaru
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Nakamura
authors.forename: Koichi
authors.initials: K
authors.lastname: Omori
mesh_terms: D000818:Animals; D005500:Follow-Up Studies; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012038:Regeneration; D020545:Respiratory Mucosa / Q000166:cytology / Q000502:physiology* / Q000637:transplantation; D023822:Tissue Engineering / Q000379:methods*; D014132:Trachea / Q000166:cytology / Q000502:physiology*; D014945:Wound Healing