title: Hydroxyapatite-coated polyurethane for auricular cartilage replacement: an in vitro study.
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.
authors.affiliation: Council for Scientific and Industrial Research, Material Science and Manutacturing, PO BOX 395, CSIR MSM, Polymers, Ceramics, and Composites, Pretoria, Gauteng, South Africa. achetty@csir.co.za
authors.forename: Avashnee
authors.initials: A
authors.lastname: Chetty
authors.forename: Tenille
authors.initials: T
authors.lastname: Steynberg
authors.forename: Sean
authors.initials: S
authors.lastname: Moolman
authors.forename: Roger
authors.initials: R
authors.lastname: Nilen
authors.forename: Annie
authors.initials: A
authors.lastname: Joubert
authors.forename: Wim
authors.initials: W
authors.lastname: Richter
mesh_terms: D002448:Cell Adhesion; D002460:Cell Line; D045744:Cell Line, Tumor; D020099:Coated Materials, Biocompatible; D004247:DNA / Q000096:biosynthesis / Q000235:genetics; D017886:Durapatite; D004425:Ear Cartilage; D005347:Fibroblasts; D005840:Gentian Violet; D006801:Humans; D020007:Implants, Experimental; D008855:Microscopy, Electron, Scanning; D011140:Polyurethanes; D011474:Prosthesis Design; D012394:Rosaniline Dyes; D013778:Tetrazolium Salts; D013844:Thiazoles; D014057:Tomography, X-Ray Computed
chemical_list: D020099:Coated Materials, Biocompatible; D011140:Polyurethanes; D012394:Rosaniline Dyes; D013778:Tetrazolium Salts; D013844:Thiazoles; D004247:DNA; D017886:Durapatite; C022616:thiazolyl blue; D005840:Gentian Violet