title: Long-Term Morphological and Microarchitectural Stability of Tissue-Engineered, Patient-Specific Auricles In Vivo.
abstract: Current techniques for autologous auricular reconstruction produce substandard ear morphologies with high levels of donor-site morbidity, whereas alloplastic implants demonstrate poor biocompatibility. Tissue engineering, in combination with noninvasive digital photogrammetry and computer-assisted design/computer-aided manufacturing technology, offers an alternative method of auricular reconstruction. Using this method, patient-specific ears composed of collagen scaffolds and auricular chondrocytes have generated auricular cartilage with great fidelity following 3 months of subcutaneous implantation, however, this short time frame may not portend long-term tissue stability. We hypothesized that constructs developed using this technique would undergo continued auricular cartilage maturation without degradation during long-term (6 month) implantation. Full-sized, juvenile human ear constructs were injection molded from high-density collagen hydrogels encapsulating juvenile bovine auricular chondrocytes and implanted subcutaneously on the backs of nude rats for 6 months. Upon explantation, constructs retained overall patient morphology and displayed no evidence of tissue necrosis. Limited contraction occurred in vivo, however, no significant change in size was observed beyond 1 month. Constructs at 6 months showed distinct auricular cartilage microstructure, featuring a self-assembled perichondrial layer, a proteoglycan-rich bulk, and rounded cellular lacunae. Verhoeff's staining also revealed a developing elastin network comparable to native tissue. Biochemical measurements for DNA, glycosaminoglycan, and hydroxyproline content and mechanical properties of aggregate modulus and hydraulic permeability showed engineered tissue to be similar to native cartilage at 6 months. Patient-specific auricular constructs demonstrated long-term stability and increased cartilage tissue development during extended implantation, and offer a potential tissue-engineered solution for the future of auricular reconstructions.
authors: 1 Meinig School of Biomedical Engineering, Cornell University , Ithaca, New York.
authors: Benjamin Peter
authors: BP
authors: Cohen
authors: 2 Laboratory for Bioregenerative Medicine and Surgery, Division of Plastic Surgery, Weill Cornell Medical College , New York, New York.
authors: Rachel C
authors: RC
authors: Hooper
authors: 1 Meinig School of Biomedical Engineering, Cornell University , Ithaca, New York.
authors: Jennifer L
authors: JL
authors: Puetzer
authors: 1 Meinig School of Biomedical Engineering, Cornell University , Ithaca, New York.
authors: Rachel
authors: R
authors: Nordberg
authors: 2 Laboratory for Bioregenerative Medicine and Surgery, Division of Plastic Surgery, Weill Cornell Medical College , New York, New York.
authors: Ope
authors: O
authors: Asanbe
authors: 2 Laboratory for Bioregenerative Medicine and Surgery, Division of Plastic Surgery, Weill Cornell Medical College , New York, New York.
authors: Karina A
authors: KA
authors: Hernandez
authors: 1 Meinig School of Biomedical Engineering, Cornell University , Ithaca, New York.|2 Laboratory for Bioregenerative Medicine and Surgery, Division of Plastic Surgery, Weill Cornell Medical College , New York, New York.
authors: Jason A
authors: JA
authors: Spector
authors: 1 Meinig School of Biomedical Engineering, Cornell University , Ithaca, New York.|3 Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York.
authors: Lawrence J
authors: LJ
authors: Bonassar
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002417:Cattle; D048430:Cell Shape; D004425:Ear Cartilage / Q000033:anatomy & histology* / Q000502:physiology*; D006801:Humans; D008297:Male; D019919:Prosthesis Implantation; D011923:Rats, Nude; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry