Physicomechanical and morphological properties of hydroxyapatite nanocrystals substituted with copper-zirconium

Biocomposites containing hydroxyapatite (HAP)/zirconia (ZrO2) were modified with different contents of copper ions using the co-precipitation technique. The phase identification is performed by X-ray diffraction (XRD) while scanning electron micrographs (FESEM) showed surface morphology and exhibited that the grain size has changed from 0.17 to 0.43 mm for the lowest and the highest additional Cu2+ ions. Moreover, the average roughness has increased from 56.4 nm to 163.8 nm, while the maximum height of the roughness (Rt) increased from 503.9 to 878.9 nm for the lowest and the highest Cu2+ additions. Furthermore, the microhardness has been investigated and exhibited a significant improvement of 2.1 +/- 0.1 to 4.6 +/- 0.3 GPa for 0.0Cu-HAP@ZrO2 and 0.8Cu-HAP@ZrO2, respectively. Moreover, the corrosion rate decreases from 0.078 to 0.070 mm/y for the lowest and the highest modified copper ions. The cell viability has enhanced from 0.2C-HAP@ZrO2 composites achieved 88.04 +/- 4%, which is the highest cell proliferation percentage. However, 0.8Cu-HAP@ZrO2 hit the highest values in both bacterial microorganisms, reaching 5.9 +/- 0.6, 5.1 +/- 0.4 mm. These significant antibacterial performances almost doubled from 0.2 to 0.8 of copper contribution is based on surface modification and amount of released reactive species that make it a promising bio applicable material. (C) 2021 The Authors. Published by Elsevier B.V.