title: Auricular reconstruction using tissue-engineered alloplastic implants for improved clinical outcomes.
abstract: BACKGROUND
  Alloplastic implants have been used clinically to treat congenital abnormalities and traumatic injuries. However, these implants are often associated with complications, including inflammation, infection, erosion, and dislodgment. To minimize these complications, the authors have developed a system in which tissue-engineered cartilage serves as a shell that entirely covers the implant. This system is designed to improve the structural and functional stability between the implant and recipient tissue.
  
  
  METHODS
  Chondrocytes isolated from rabbit ear cartilage were expanded in vitro. The cells were mixed with fibrin hydrogel for spray-coating a human ear-shaped implant. The surface of the implant was modified using an oxidizing solution to provide hydrophilic characteristic; thus, the cell-fibrin suspension readily adhered onto the surface of the implants. The engineered cartilage-covered implants were implanted into the dorsal subcutaneous space of athymic mice. Histologic and gross examinations of the implants were performed at 2, 4, 8, and 12 weeks after implantation.
  
  
  RESULTS
  None of the engineered cartilage-covered implants showed evidence of skin necrosis, implant exposure, or extrusion (n = 10). However, the control implants developed extensive necrosis following implantation (n = 10). In the experimental group, histologic evaluations showed the formation of neocartilage covering the implants. The presence of sulfated glycosaminoglycans was evident in the engineered cartilage tissue.
  
  
  CONCLUSIONS
  These results demonstrate that engineered cartilage tissues can be used as a biological cover for an alloplastic implant. This system may improve the structural and functional interactions between the implant and the recipient's tissues and thus enhance the outcome of total auricular reconstruction.
authors.affiliation: Winston-Salem, N.C.; and Jeonju and Seoul, Republic of Korea From the Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine; Polymer Fusion Research Center, Department of Polymer-Nano Science and Technology, Chonbuk National University; and the Department of Oral and Maxillofacial Surgery, Asan Medical Center, College of Medicine, Ulsan University.
authors.forename: Chang Mo
authors.initials: CM
authors.lastname: Hwang
authors.forename: Bu-Kyu
authors.initials: BK
authors.lastname: Lee
authors.forename: Denethia
authors.initials: D
authors.lastname: Green
authors.forename: Seon Yeong
authors.initials: SY
authors.lastname: Jeong
authors.forename: Gilson
authors.initials: G
authors.lastname: Khang
authors.forename: John D
authors.initials: JD
authors.lastname: Jackson
authors.forename: Anthony
authors.initials: A
authors.lastname: Atala
authors.forename: Sang Jin
authors.initials: SJ
authors.lastname: Lee
authors.forename: James J
authors.initials: JJ
authors.lastname: Yoo
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D019902:Chondrocytes / Q000502:physiology; D054644:Ear Auricle / Q000166:cytology*; D004425:Ear Cartilage / Q000166:cytology*; D006085:Graft Survival; D008297:Male; D051379:Mice; D008819:Mice, Nude; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D011817:Rabbits; D023822:Tissue Engineering