title: High-fidelity tissue engineering of patient-specific auricles for reconstruction of pediatric microtia and other auricular deformities.
abstract: BACKGROUND
  Autologous techniques for the reconstruction of pediatric microtia often result in suboptimal aesthetic outcomes and morbidity at the costal cartilage donor site. We therefore sought to combine digital photogrammetry with CAD/CAM techniques to develop collagen type I hydrogel scaffolds and their respective molds that would precisely mimic the normal anatomy of the patient-specific external ear as well as recapitulate the complex biomechanical properties of native auricular elastic cartilage while avoiding the morbidity of traditional autologous reconstructions.
  
  
  METHODS
  Three-dimensional structures of normal pediatric ears were digitized and converted to virtual solids for mold design. Image-based synthetic reconstructions of these ears were fabricated from collagen type I hydrogels. Half were seeded with bovine auricular chondrocytes. Cellular and acellular constructs were implanted subcutaneously in the dorsa of nude rats and harvested after 1 and 3 months.
  
  
  RESULTS
  Gross inspection revealed that acellular implants had significantly decreased in size by 1 month. Cellular constructs retained their contour/projection from the animals' dorsa, even after 3 months. Post-harvest weight of cellular constructs was significantly greater than that of acellular constructs after 1 and 3 months. Safranin O-staining revealed that cellular constructs demonstrated evidence of a self-assembled perichondrial layer and copious neocartilage deposition. Verhoeff staining of 1 month cellular constructs revealed de novo elastic cartilage deposition, which was even more extensive and robust after 3 months. The equilibrium modulus and hydraulic permeability of cellular constructs were not significantly different from native bovine auricular cartilage after 3 months.
  
  
  CONCLUSIONS
  We have developed high-fidelity, biocompatible, patient-specific tissue-engineered constructs for auricular reconstruction which largely mimic the native auricle both biomechanically and histologically, even after an extended period of implantation. This strategy holds immense potential for durable patient-specific tissue-engineered anatomically proper auricular reconstructions in the future.
authors: Laboratory for Bioregenerative Medicine and Surgery, Division of Plastic Surgery, Weill Cornell Medical College, New York, New York, USA. Jas2037@med.cornell.edu
authors: Alyssa J
authors: AJ
authors: Reiffel
authors: Concepcion
authors: C
authors: Kafka
authors: Karina A
authors: KA
authors: Hernandez
authors: Samantha
authors: S
authors: Popa
authors: Justin L
authors: JL
authors: Perez
authors: Sherry
authors: S
authors: Zhou
authors: Satadru
authors: S
authors: Pramanik
authors: Bryan N
authors: BN
authors: Brown
authors: Won Seuk
authors: WS
authors: Ryu
authors: Lawrence J
authors: LJ
authors: Bonassar
authors: Jason A
authors: JA
authors: Spector
mesh_terms: D000818:Animals; D002417:Cattle; D002648:Child; D019902:Chondrocytes / Q000166:cytology / Q000378:metabolism; D024042:Collagen Type I / Q000737:chemistry / Q000502:physiology*; D017076:Computer-Aided Design; D054644:Ear Auricle / Q000033:anatomy & histology / Q000254:growth & development*; D004425:Ear Cartilage / Q000254:growth & development* / Q000601:surgery; D004431:Ear, External / Q000254:growth & development / Q000601:surgery; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D008297:Male; D019736:Prostheses and Implants; D051381:Rats; D019651:Plastic Surgery Procedures; D023822:Tissue Engineering
chemical_list: D024042:Collagen Type I; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate