title: Mastoid obliteration by BMP-2/collagen composites: an experimental study using tissue engineering.
abstract: OBJECTIVE
  Several materials have been used in the application of mastoid cavity obliteration during surgery for cholesteatoma; however, nothing has won universal acceptance. Through the advancement of tissue engineering, bone morphogenetic protein-2 (BMP-2)/collagen composites have been elucidated as inducers of heterogenic bone formation. This study was performed to investigate whether these composites are potentially obliteration materials for use in the mastoid cavity by using an animal experimental study.
  
  
  METHODS
  The composites were implanted in the rat mastoid to investigate whether new bone would be tissue engineered in the mastoid and, if so, whether the newly formed bone was stable. The composites were examined histologically over a 24-week period.
  
  
  RESULTS
  The composites implanted in the rat mastoid were able to tissue engineer new bone, and the newly formed bone was stable as assessed histologically, with almost normal bone structure, that was not resorbed during the 24-week period. Adverse immunological reactions were not found during our observation.
  
  
  CONCLUSIONS
  Bone that was tissue engineered by the BMP-2/collagen composites was stable as assessed by histological examination and persisted in the rat mastoid. The present study shows that the composites have the potential to become real materials for use in mastoid obliteration.
authors.affiliation: Departments of Otolaryngology-Head and Neck Surgery, Okayama University Graduate Schools, Okayama, Japan. nishizak@cc.okayama-u.ac.jp
authors.forename: Kazunori
authors.initials: K
authors.lastname: Nishizaki
authors.forename: Hidetsugu
authors.initials: H
authors.lastname: Tsujigiwa
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Takeda
authors.forename: Tadashi
authors.initials: T
authors.lastname: Yoshino
authors.forename: Manabu
authors.initials: M
authors.lastname: Maeta
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Fukushima
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Nagatsuka
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Nagai
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology*; D018424:Cholesteatoma, Middle Ear / Q000601:surgery*; D003094:Collagen / Q000494:pharmacology*; D008297:Male; D008416:Mastoid / Q000187:drug effects* / Q000473:pathology*; D016348:Osseointegration / Q000502:physiology; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D023822:Tissue Engineering / Q000379:methods*; D016212:Transforming Growth Factor beta
chemical_list: C525720:Bmp2 protein, rat; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D016212:Transforming Growth Factor beta; D003094:Collagen