Hydroxyapatite-coated polyurethane for auricular cartilage replacement: An in vitro study

Authors

  • Avashnee Chetty,

    Corresponding author
    1. Council for Scientific and Industrial Research (CSIR), Material Science and Manutacturing (MSM), PO BOX 395, CSIR MSM, Polymers, Ceramics, and Composites, Pretoria, Gauteng, South Africa
    • Council for Scientific and Industrial Research (CSIR), Material Science and Manutacturing (MSM), PO BOX 395, CSIR MSM, Polymers, Ceramics, and Composites, Pretoria, Gauteng, South Africa
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  • Tenille Steynberg,

    1. Department of Physiology, University of Pretoria, Gauteng, Pretoria, South Africa
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  • Sean Moolman,

    1. Council for Scientific and Industrial Research (CSIR), Material Science and Manutacturing (MSM), PO BOX 395, CSIR MSM, Polymers, Ceramics, and Composites, Pretoria, Gauteng, South Africa
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  • Roger Nilen,

    1. Council for Scientific and Industrial Research (CSIR), Material Science and Manutacturing (MSM), PO BOX 395, CSIR MSM, Polymers, Ceramics, and Composites, Pretoria, Gauteng, South Africa
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  • Annie Joubert,

    1. Department of Physiology, University of Pretoria, Gauteng, Pretoria, South Africa
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  • Wim Richter

    1. Council for Scientific and Industrial Research (CSIR), Material Science and Manutacturing (MSM), PO BOX 395, CSIR MSM, Polymers, Ceramics, and Composites, Pretoria, Gauteng, South Africa
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Abstract

Auricular reconstruction remains a major challenge facing reconstructive surgeons owing to the complexity of autogenous transplants. In this study, the development of a three-dimensional custom-made polyurethane (PU) auricular implant with hydroxyapatite (HA) coating is described. The PU implant was produced by computerized tomography (CT) scanning and indirect rapid prototyping. To improve the physiological response of the implant, the PU prototype was coated with a microrough, homogenous layer of HA by a novel solvent-compression coating method. Bioactivity of the HA coated PU substrates was confirmed by apatite formation on the HA coating after 9 days in revised simulated body fluid (pH 7.4). Adhesion strength of the HA coating to the PU surface using the tensile pull-off test revealed partial failure of the coating with an average tensile strength of 1.6 MPa. As an initial stage indication of cytocompatibility for a soft tissue application, in vitro cell culturing on the HA-coated PU substrates using Graham 293 fibroblast cells was performed. After 24 and 72 h, the HA coated surfaces displayed significantly higher cell numbers and metabolically active cells compared with the virgin uncoated PU surfaces. This indicates that HA coated PU surfaces are cytocompatible towards fibroblasts and could potentially be applied to auricular cartilage tissue replacement. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008

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