Materials (Sep 2020)

Zn- or Cu-containing CaP-Based Coatings Formed by Micro-Arc Oxidation on Titanium and Ti-40Nb Alloy: Part II—Wettability and Biological Performance

  • Ekaterina G. Komarova,
  • Yurii P. Sharkeev,
  • Mariya B. Sedelnikova,
  • Oleg Prymak,
  • Matthias Epple,
  • Larisa S. Litvinova,
  • Valeria V. Shupletsova,
  • Vladimir V. Malashchenko,
  • Kristina A. Yurova,
  • Anna N. Dzyuman,
  • Irina V. Kulagina,
  • Lyudmila S. Mushtovatova,
  • Olga P. Bochkareva,
  • Mariia R. Karpova,
  • Igor A. Khlusov

DOI
https://doi.org/10.3390/ma13194366
Journal volume & issue
Vol. 13, no. 19
p. 4366

Abstract

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This work describes the wettability and biological performance of Zn- and Cu-containing CaP-based coatings prepared by micro-arc oxidation on pure titanium (Ti) and novel Ti-40Nb alloy. Good hydrophilic properties of all the coatings were demonstrated by the low contact angles with liquids, not exceeding 45°. An increase in the applied voltage led to an increase of the coating roughness and porosity, thereby reducing the contact angles to 6° with water and to 17° with glycerol. The free surface energy of 75 ± 3 mJ/m2 for all the coatings were determined. Polar component was calculated as the main component of surface energy, caused by the presence of strong polar PO43− and OH− bonds. In vitro studies showed that low Cu and Zn amounts (~0.4 at.%) in the coatings promoted high motility of human adipose-derived multipotent mesenchymal stromal cells (hAMMSC) on the implant/cell interface and subsequent cell ability to differentiate into osteoblasts. In vivo study demonstrated 100% ectopic bone formation only on the surface of the CaP coating on Ti. The Zn- and Cu-containing CaP coatings on both substrates and the CaP coating on the Ti-40Nb alloy slightly decreased the incidence of ectopic osteogenesis down to 67%. The MAO coatings showed antibacterial efficacy against Staphylococcus aureus and can be arranged as follows: Zn-CaP/Ti > Cu-CaP/TiNb, Zn-CaP/TiNb > Cu-CaP/Ti.

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