Antibacterial Copper–Hydroxyapatite Composite Coatings via Electrochemical Synthesis

Abstract

Antibacterial copper−hydroxyapatite (Cu−HA) composite coatings on titanium were synthesized using a novel process consisting of two consecutive electrochemical reactions. In the first stage, HA nanocrystals were grown on titanium using the cathodic electrolytic synthesis. The HAcoated titanium was then used as the cathode in a second reaction stage to electrochemically reduce Cu 2+ ions in solution to metallic Cu nanoparticles. Reaction conditions were found that result in nanoscale Cu particles growing on the surface of the HA crystals. The two-stage synthesis allows facile control of copper content in the HA coatings. Antibacterial activity was measured by culturing Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) in the presence of coatings having varying copper contents. The coatings displayed copper concentration-dependent antibacterial activity against both types of bacteria, likely due to the slow release of copper ions from the coatings. The observation of antibacterial activity from a relatively low loading of copper on the bioactive HA support suggests that multifunctional implant coatings can be developed to supplement or supplant prophylactic antibiotics used in implant surgery that are responsible for creating resistant bacteria strains.

Microstructure, Wettability, Corrosion Resistance and Antibacterial Property of Cu-MTa2O5 Multilayer Composite Coatings with Different Cu Incorporation Contents

“…Moreover, after contact with bacteria, Cu ions penetrate the membrane into the cell, which destroys membrane integrity and leads to cell death due to the leakage of the cytoplasm such as proteins and reducing sugars [61]. In addition, Cu ions entering the cell can damage the respiratory chain of the bacterial, cause the production of a large amount of ROS, degradation of DNA and proteins, and ultimately cell death [26]. The antibacterial activity of C0 sample is related to the amorphous structure [62] and the release of Ta 5+ ions [24].…”

Antibacterial and Osteogenic Functionalization of Titanium With Silicon/Copper-Doped High-Energy Shot Peening-Assisted Micro-Arc Oxidation Technique

“…These locally drug-releasing coatings can allow for low-dose and long-lasting drug therapy, and prevent side effects of the drug on normal tissues or organs ( Maher et al, 2018 ). At present, the active antibacterial agents commonly used in the treatment of Ti-based implants include antibiotics, antimicrobial peptides, and metal ions ( Liu et al, 2017 ; Ghosh et al, 2019 ; Shen et al, 2019a ). However, long-term antibiotics usage may induce drug-resistant bacteria, furthermore, antimicrobial peptides are relatively expensive, so the metal ions-rich antibacterial coatings provide a more extensive application prospect.…”

Tailoring the Surface Morphology and the Crystallinity State of Cu- and Zn-Substituted Hydroxyapatites on Ti and Mg-Based Alloys

“…Ideally, the deposited coating not only should possess an antibacterial effect, but also increase bone healing and improve osseointegration. From that perspective, substituted hydroxyapatites (HA) are one of the most promising materials for biomedical coatings [ 11 , 12 , 13 ]. It has been shown that inorganic antibacterial metallic ions (e.g., Cu, Zn, and Ag) can be introduced into the HA lattice and improve its antibacterial properties [ 14 , 15 , 16 , 17 , 18 , 19 , 20 ].…”