title: Conditions for seeding and promoting neo-auricular cartilage formation in a fibrous collagen scaffold.
abstract: BACKGROUND
  Carved autologous costal cartilage and porous polyethylene implants (Medpor) are the most common approaches for total ear reconstruction, but these approaches may have inconsistent cosmetic outcomes, a high risk of extrusion, or other surgical complications. Engineering ear cartilage to emulate native auricular tissue is an appealing approach, but often the cell-seeded scaffolds are susceptible to shrinkage and architectural changes when placed in vivo. The aim of this study was to assess the most favorable conditions for in vitro pre-culture of cell-seeded type I collagen scaffolds prior to in vivo implantation.
  
  
  METHODS
  Sheep auricular chondrocytes were seeded into this type I collagen scaffold. The cell-seeded constructs were cultured in either static or dynamic conditions for two days or two weeks and then implanted into nude mice for another six weeks. The harvested constructs were evaluated histologically, immunohistochemically, and biochemically.
  
  
  RESULTS
  Robust neo-cartilage formation was found in these collagen scaffolds seeded with auricular chondrocytes, which was comparable to native cartilage morphologically, histologically, and biochemically. Culture under dynamic conditions prior to implantation improved the neo-cartilage formation histologically and biochemically.
  
  
  CONCLUSIONS
  Dynamic culture of this cell-seeded fibrous collagen material could permit predictable engineered auricular cartilage and a promising approach for external ear reconstruction.
authors.affiliation: Plastic Surgery Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Department of Orthopaedics, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Xing
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Plastic Surgery Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Bichara
authors.affiliation: Laboratory for Tissue Engineering & Organ Fabrication, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Department of Stomatology, The 513rd Hospital of PLA, Lanzhou 732750, Gansu, PR China.
authors.forename: Libin
authors.initials: L
authors.lastname: Zhou
authors.affiliation: Laboratory for Tissue Engineering & Organ Fabrication, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Kulig
authors.affiliation: Laboratory for Tissue Engineering & Organ Fabrication, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Alan
authors.initials: A
authors.lastname: Tseng
authors.affiliation: Kensey Nash Corporation, Exton, PA, USA.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Bowley
authors.affiliation: Laboratory for Tissue Engineering & Organ Fabrication, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Vacanti
authors.affiliation: Laboratory for Tissue Engineering & Organ Fabrication, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Irina
authors.initials: I
authors.lastname: Pomerantseva
authors.affiliation: Laboratory for Tissue Engineering & Organ Fabrication, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Cathryn A
authors.initials: CA
authors.lastname: Sundback
authors.affiliation: Plastic Surgery Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA. Electronic address: marandolph@partners.org.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Randolph
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques; D002469:Cell Separation / Q000379:methods; D002478:Cells, Cultured; D019902:Chondrocytes / Q000502:physiology*; D020219:Chondrogenesis / Q000502:physiology; D024042:Collagen Type I / Q000737:chemistry*; D004247:DNA / Q000032:analysis; D004425:Ear Cartilage / Q000033:anatomy & histology / Q000737:chemistry / Q000166:cytology*; D004549:Elastin / Q000032:analysis; D006025:Glycosaminoglycans / Q000032:analysis; D006909:Hydroxyproline / Q000032:analysis; D051379:Mice; D008819:Mice, Nude; D012756:Sheep; D040521:Subcutaneous Tissue / Q000601:surgery; D013499:Surface Properties; D013997:Time Factors; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D024042:Collagen Type I; D006025:Glycosaminoglycans; D004247:DNA; D004549:Elastin; D006909:Hydroxyproline
keywords: Auricle; Cartilage; Collagen; Ear; Scaffold; Tissue engineering