title: Engineered nasal cartilage by cell homing: a model for augmentative and reconstructive rhinoplasty.
abstract: BACKGROUND
  Current augmentative and reconstructive rhinoplasties use auto logous tissue grafts or synthetic bioinert materials to repair nasal trauma or attain an aesthetic shape. Autologous grafts are associated with donor-site trauma and morbidity. Synthetic materials are widely used but often yield an unnatural appearance and are prone to infection or dislocation. There is an acute clinical need for the generation of native tissues to serve as rhinoplasty grafts without the undesirable features that are associated with autologous grafts or current synthetic materials.
  
  
  METHODS
  Bioactive scaffolds were developed that not only recruited cells in the nasal dorsum in vivo, but also induced chondrogenesis of the recruited cells. Bilayered scaffolds were fabricated with alginate-containing gelatin microspheres encapsulating cytokines atop a porous poly(lactic-co-glycolic acid) base. Microspheres were fabricated to contain recombinant human transforming growth factor-β3 at doses of 200, 500, or 1000 ng, with phosphate-buffered saline-loaded microspheres used as a control. A rat model of augmentation rhinoplasty was created by implanting scaffolds atop the native nasal cartilage surface that was scored to induce cell migration. Tissue formation and chondrogenesis in the scaffolds were evaluated by image analysis and histologic staining with hematoxylin and eosin, toluidine blue, Verhoeff elastic-van Geison, and aggrecan immunohistochemistry.
  
  
  RESULTS
  Sustained release of increasing doses of transforming growth factor-β3 for up to the tested 10 weeks promoted orthotopic cartilage-like tissue formation in a dose-dependent manner.
  
  
  CONCLUSIONS
  These findings represent the first attempt to engineer cartilage tissue by cell homing for rhinoplasty, and could potentially serve as an alternative material for augmentative and reconstructive rhinoplasty.
authors.affiliation: New York, N.Y. From the Center for Craniofacial Regeneration and the Department of Otolaryngology-Head and Neck Surgery, Columbia University Medical Center; and the Department of Biomedical Engineering, Columbia University.
authors.forename: Avital
authors.initials: A
authors.lastname: Mendelson
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Ahn
authors.forename: Kamila
authors.initials: K
authors.lastname: Paluch
authors.forename: Mildred C
authors.initials: MC
authors.lastname: Embree
authors.forename: Jeremy J
authors.initials: JJ
authors.lastname: Mao
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000627:therapeutic use; D002465:Cell Movement; D020219:Chondrogenesis / Q000502:physiology; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D019344:Lactic Acid / Q000627:therapeutic use; D059630:Mesenchymal Stem Cells / Q000166:cytology; D008863:Microspheres; D023421:Models, Animal; D055171:Nasal Cartilages / Q000166:cytology; D011100:Polyglycolic Acid / Q000627:therapeutic use; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D051381:Rats; D017207:Rats, Sprague-Dawley; D019651:Plastic Surgery Procedures; D012225:Rhinoplasty / Q000379:methods*; D046509:Tissue Culture Techniques / Q000379:methods*; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds; D053782:Transforming Growth Factor beta3 / Q000008:administration & dosage
chemical_list: D001672:Biocompatible Materials; D020099:Coated Materials, Biocompatible; D053782:Transforming Growth Factor beta3; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid