title: Human tracheal chondrocytes as a cell source for augmenting stenotic tracheal segments: the first feasibility study in an in vivo culture system.
abstract: BACKGROUND
  Construction of engineered respiratory tract using tissue-engineered cartilage has not yet been reported. In order to generate artificial trachea using human chondrocytes obtained from tracheal cartilage, we investigated whether human tracheal chondrocytes can act as a cell source to fabricate engineered airway patches to augment stenotic parts of the trachea.
  
  
  METHODS
  After informed consent, chondrocytes were obtained from five patients who needed tracheal surgery. A small piece of resected tracheal cartilage was digested by collagenase type 2 for 3-4 h. This yielded chondrocytes, which were expanded in vitro and seeded onto biodegradable scaffolds; these were then implanted subcutaneously in athymic mice. The implanted constructs were retrieved 8 weeks later for histologic and biochemical analysis.
  
  
  RESULTS
  In monolayer cultures, chondrocytes proliferated well, showing a 100- to 1,000-fold increase in 1 month. Once expanded, the cells lost their original morphological and biologic characteristics, but the engrafted scaffold showed histologic and biochemical characteristics of cartilage. Viable chondrocytes and extracellular matrix were detected, and glycosaminoglycan (GAG) in vivo was present.
  
  
  CONCLUSIONS
  Here we show that a small piece of human tracheal cartilage can generate sufficient chondrocytes in vitro and form tracheal cartilage architecture in an in vivo environment.
authors.affiliation: The Department of Pediatric Surgery, Graduate School of Medicine, University of Tokyo, Tokyo, Japan. komura-tky@umin.ac.jp
authors.forename: Makoto
authors.initials: M
authors.lastname: Komura
authors.forename: Hiroko
authors.initials: H
authors.lastname: Komura
authors.forename: Yujirou
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kanamori
authors.forename: Masahiko
authors.initials: M
authors.lastname: Sugiyama
authors.forename: Saori
authors.initials: S
authors.lastname: Nakahara
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawashima
authors.forename: Kan
authors.initials: K
authors.lastname: Suzuki
authors.forename: Kazuto
authors.initials: K
authors.lastname: Hoshi
authors.forename: Tadashi
authors.initials: T
authors.lastname: Iwanaka