title: Study of mechanical properties of engineered cartilage in an in vivo culture for design of a biodegradable scaffold.
abstract: BACKGROUND
  An engineered trachea with an absorbable scaffold should be used to augment the repair of a stenotic tracheal section in infants and children because this type of engineered airway structure can grow as the child grows. Our strategy for relief of tracheal stenosis is tracheoplasty by engineered cartilage implantation in accordance with the concept of costal cartilage grafting to enlarge the lumen. This study investigated the mechanical properties of regenerative cartilage with a biodegradable scaffold, Neoveil®, to aid in design of a composite scaffold that maintained semi-rigid properties until cartilage could be generated.
  
  
  METHODS
  New Zealand White rabbit (n=3) chondrocytes were isolated from auricular cartilage with collagenase type 2 digestion. Then 10x10(6)/cm3 chondrocytes in atelocollagen solution were seeded onto polyglycolic acid (PGA) mesh. A total of 36 constructs, 12 from each rabbit, were implanted into athymic mice (3 constructs/mouse). Constructs were retrieved after 8 weeks and evaluated by measurements of mechanical and biochemical properties as well as histological examination. Thirty-six PGA mesh sheets of the same size but without cells were implanted in control mice.
  
  
  RESULTS
  After 6 weeks of implantation, staining of sections with Safranin O revealed cartilage accumulation. Glycosaminoglycan was gradually produced from chondrocytes in the engineered constructs, correlating with the duration of implantation. Mechanical parameters had the same values as those for rabbit tracheal cartilage 8 weeks after implantation.
  
  
  CONCLUSIONS
  Biodegradable Neoveil® had good biocompatibility and was able to support extracellular matrix formation in engineered cartilage in an animal model.
authors.affiliation: 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: Yutaka
authors.initials: Y
authors.lastname: Kanamori
authors.forename: Yujirou
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Ohatani
authors.forename: Tetuya
authors.initials: T
authors.lastname: Ishimaru
authors.forename: Masahiko
authors.initials: M
authors.lastname: Sugiyama
authors.forename: Kazuto
authors.initials: K
authors.lastname: Hoshi
authors.forename: Tadashi
authors.initials: T
authors.lastname: Iwanaka
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001696:Biomechanical Phenomena; D002356:Cartilage / Q000166:cytology / Q000378:metabolism / Q000637:transplantation*; D002478:Cells, Cultured; D019902:Chondrocytes / Q000378:metabolism / Q000637:transplantation*; D005109:Extracellular Matrix / Q000378:metabolism; D006025:Glycosaminoglycans / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D011817:Rabbits; D012038:Regeneration; D013997:Time Factors; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds; D014132:Trachea / Q000166:cytology / Q000378:metabolism / Q000637:transplantation*
chemical_list: D006025:Glycosaminoglycans