Comparative Study of the Structure, Properties, and Corrosion Behavior of Sr-Containing Biocoatings on Mg0.8Ca

Mariya B Sedelnikova; Yurii P Sharkeev; Tatiana V Tolkacheva; Margarita A Khimich; Olga V Bakina; Alla N Fomenko; Aigerim A Kazakbaeva; Inna V Fadeeva; Vladimir S Egorkin; Sergey V Gnedenkov; Juergen Schmidt; Kateryna Loza; Oleg Prymak; Matthias Epple

doi:10.3390/ma13081942

Comparative Study of the Structure, Properties, and Corrosion Behavior of Sr-Containing Biocoatings on Mg0.8Ca

Materials (Basel). 2020 Apr 20;13(8):1942. doi: 10.3390/ma13081942.

Authors

Affiliations

¹ Laboratory of Physics of Nanostructured Biocomposites, Institute of Strength Physics and Materials Science of SB RAS, Tomsk 634055, Russia.
² Research School of High-Energy Physics, National Research Tomsk Polytechnic University, Tomsk 634050, Russia.
³ Faculty of Physics and Engineering, National Research Tomsk State University, Tomsk 634050, Russia.
⁴ Institute of Metallurgy and Materials Science of A.A. Baikov of RAS, Moscow 119334, Russia.
⁵ Institute of Chemistry FEB RAS, Vladivostok 690022, Russia.
⁶ Department of Electrochemistry, Innovent Technology Development, D-07745 Jena, Germany.
⁷ Inorganic Chemistry and Center for Nanointegration Duisburg-Essen (CeNIDE), University of Duisburg-Essen, 45117 Essen, Germany.

Abstract

A comparative analysis of the structure, properties and the corrosion behavior of the micro-arc coatings based on Sr-substituted hydroxyapatite (Sr-HA) and Sr-substituted tricalcium phosphate (Sr-TCP) deposited on Mg0.8Ca alloy substrates was performed. The current density during the formation of the Sr-HA coatings was higher than that for the Sr-TCP coatings. As a result, the Sr-HA coatings were thicker and had a greater surface roughness R_a than the Sr-TCP coatings. In addition, pore sizes of the Sr-HA were almost two times larger. The ratio (Ca + Sr + Mg)/P were equal 1.64 and 1.47 for Sr-HA and Sr-TCP coatings, respectively. Thus, it can be assumed that the composition of Sr-HA and Sr-TCP coatings was predominantly presented by (Sr,Mg)-substituted hydroxyapatite and (Sr,Mg)-substituted tricalcium phosphate. However, the average content of Sr was approximately the same for both types of the coatings and was equal to 1.8 at.%. The Sr-HA coatings were less soluble and had higher corrosion resistance than the Sr-TCP coatings. Cytotoxic tests in vitro demonstrated a higher cell viability after cultivation with extracts of the Sr-HA coatings.

Keywords: Sr-hydroxyapatite; Sr-tricalcium phosphate; biocoatings; cell viability; corrosion resistance; magnesium alloy; micro-arc oxidation; structure.