title: Bioactivity and biocompatibility of hydroxyapatite-based bioceramic coatings on zirconium by plasma electrolytic oxidation.
abstract: In the present work, hydroxyapatite (HAP)-based plasma electrolytic oxide (PEO) coatings were produced on zirconium at different current densities in a solution containing calcium acetate and β-calcium glycerophosphate by a single step. The phase structure, surface morphology, functional groups, thickness and roughness of the coatings were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), eddy current method and surface profilometer, respectively. The phases of cubic-zirconia, calcium zirconate and HAP were detected by XRD. The amount of HAP and calcium zirconate increased with increasing current density. The surface of the coatings was very porous and rough. Moreover, bioactivity and biocompatibility of the coatings were analyzed in vitro immersion simulated body fluid (SBF) and MTT (3-(4,5-dimethyl thiazol-2yl)-2,5-diphenyl tetrazolium bromide) assay, hemolysis assay and bacterial formation. The apatite-forming ability of the coatings was evaluated after immersion in SBF up to 28days. After immersion, the bioactivity of HAP-based coatings on zirconium was greater than the ones of uncoated zirconium and zirconium oxide-based surface. The bioactivity of PEO surface on zirconium was significantly improved under SBF conditions. The bacterial adhesion of the coatings decreased with increasing current density. The bacterial adhesion of the coating produced at 0.370A/cm2was minimum compared to uncoated zirconium coated at 0.260 and 0.292A/cm2. The hemocompatibility of HAP-based surfaces was improved by PEO. The cell attachment and proliferation of the PEO coatings were better than the one of uncoated zirconium according to MTT assay results.
authors.affiliation: The Department of Materials Science and Engineering, Gebze Technical University, Gebze, Kocaeli 41400, Turkey. Electronic address: saktug@gtu.edu.tr.
authors.forename: Salim Levent
authors.initials: SL
authors.lastname: Aktuğ
authors.affiliation: The Department of Industrial Engineering, Giresun University, Merkez, Giresun 28200, Turkey. Electronic address: durdusalih@gmail.com.
authors.forename: Salih
authors.initials: S
authors.lastname: Durdu
authors.affiliation: The Department of Biology, Giresun University, Merkez, Giresun 28200, Turkey. Electronic address: emine.yalcin@giresun.edu.tr.
authors.forename: Emine
authors.initials: E
authors.lastname: Yalçın
authors.affiliation: The Department of Biology, Giresun University, Merkez, Giresun 28200, Turkey. Electronic address: kultigin.cavusoglu@giresun.edu.tr.
authors.forename: Kültigin
authors.initials: K
authors.lastname: Çavuşoğlu
authors.affiliation: The Department of Materials Science and Engineering, Gebze Technical University, Gebze, Kocaeli 41400, Turkey; Materials Institute, Marmara Research Center, TUBITAK, Gebze, Kocaeli 41470, Turkey. Electronic address: ustam@gtu.edu.tr.
authors.forename: Metin
authors.initials: M
authors.lastname: Usta
mesh_terms: D000818:Animals; D002516:Ceramics / Q000737:chemistry / Q000494:pharmacology; D020099:Coated Materials, Biocompatible / Q000737:chemistry / Q000494:pharmacology; D017886:Durapatite / Q000737:chemistry / Q000494:pharmacology; D006090:Gram-Negative Bacteria / Q000254:growth & development*; D006094:Gram-Positive Bacteria / Q000254:growth & development*; D006461:Hemolysis / Q000187:drug effects*; D010084:Oxidation-Reduction; D058626:Plasma Gases / Q000737:chemistry*; D011817:Rabbits; D015040:Zirconium / Q000737:chemistry / Q000494:pharmacology
chemical_list: D020099:Coated Materials, Biocompatible; D058626:Plasma Gases; D017886:Durapatite; D015040:Zirconium
keywords: Bioactivity; Biocompatibility; Hydroxyapatite (HAP); Plasma electrolytic oxidation (PEO); Zirconium