Improvements of Corrosion Resistance and Antibacterial Properties of Hydroxyapatite/Cupric Oxide Doped Titania Composite Coatings on Degradable Magnesium Alloys

Abstract

The excellent biocompatibility of calcium phosphate (CaP) coatings makes them widely used in magnesium (Mg) alloy orthopedic implant materials. However, the porous morphology of CaP coatings limits their corrosion resistance. A cupric oxide (CuO) doped titania (TiO 2 ) sol− gel coating is prepared on a porous hydroxyapatite (HA) coating. According to electrochemical test results, the HA/CuO−TiO 2 coating obtains a current density of 6 × 10 −4 mA/cm 2 , lower than that of the Mg alloy (2.6 × 10 −2 mA/cm 2 ). The hydrogen evaluation of the HA/CuO−TiO 2 coating is only 1/12 that of the Mg alloy after immersion for 7 days. In addition, the HA/CuO−TiO 2 coating has an antibacterial rate of 99.5 ± 0.4% against Staphylococcus aureus, significantly higher than that of the HA coating (19.8 ± 0.3%) and HTC0 coating (38.4 ± 0.5%). The CuO doped composite coating has no adverse effect or cytotoxicity on cell proliferation (cell viability ≥79.6%). Hence, the HA/ CuO−TiO 2 composite coating is useful for enhancing the corrosion resistance and antibacterial properties of Mg alloys while ensuring cytocompatibility. The HA/CuO−TiO 2 coated AZ60 Mg alloy can meet the requirements of clinical application.

Surface engineering of biodegradable implants: emerging trends in bioactive ceramic coatings and mechanical treatments

“…This challenge was resolved by depositing another coating of copper oxide-doped titanium oxide with improved corrosion resistance. The layered coating showed good biocompatibility in addition to enhanced antibacterial activity 199 . Thus, doped ceramic coatings impart better biological properties in comparison to undoped coating.…”

Effect of Strontium-Substituted Calcium Phosphate Coatings Prepared by One-Step Electrodeposition at Different Temperatures on Corrosion Resistance and Biocompatibility of AZ31 Magnesium Alloys

“…In order to achieve the application standard of temporary bone repair materials, it is crucial to control the degradation rate of Mg alloy; otherwise, the local alkalinization and hydrogen cavity because of the natural degradation of Mg under physiological conditions will delay the wound healing process. 9−11 At present, a number of studies have shown that the degradation rate of Mg could be controlled by surface modification technologies such as chemical conversion, 12,13 hydrothermal method, 14 sol−gel method, 15 polymer coatings, 16 plasma spraying, 17 microarc oxidation, 18 magnetron sputtering, 19 and electrochemical deposition. 20 Its biocompatibility could be further improved at the same time.…”

Organo-metallic electrolyte additive for regulating hydrogen evolution and self-discharge in Mg–air aqueous battery

“…13 Alternatively, subduing the current density and viscosity of the electrolyte could prolong the utilization efficiency with less anodic corrosion. 14,15 Yet, the accomplishment of high energy density and quick charging is a problematic concern. 16,17 The primary scope of this work is to enhance the anodic utilization efficiency of the Mg–air battery based on a salt electrolyte system via the simple strategy of controlling the electrochemical reactions at the anode with the incorporation of corrosion inhibitors and sustainable capture and the usage of carbon as a cathodic catalyst layer obtained from the eco-friendly conversion of polyethylene waste.…”