The corrosion resistance and anti-bacterial performance of polyelectrolyte-embedded Ca-P coating loaded with ciprofloxacin on magnesium alloy

Abstract

Polyacrylic acid (PAA) is utilized as the template for the hydrothermal fabrication of Ca-P coatings on biodegradable magnesium (Mg) alloys, and ciprofloxacin (CIP) is also adopted for the coating's anti-bacterial performance. The coating's composition and structure are characterized. The anti-bacterial performance of the coating is evaluated using plate counting method against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The corrosion rates of different samples are measured by electrochemical polarization, electrochemical impedance spectroscopy (EIS), and hydrogen evolution (HE) experiments. The long-term release behavior of the loaded antibiotics is analyzed through UV–vis. The results show that the obtained coating would display corrosion protection, anti-bacterial effect, and acceptable adhesive force, verifying that this drug-loaded coating effectively overcomes the limitations of Mg alloys in the biological environment. The biocompatibility of the coating is also characterized using the CCK-8 method. Finally, the role of the PAA in the structural transformation of the coating is explained based on the molecular dynamics (MD) simulation and this method seems to open a new pathway for understanding the reconstructing effect of the templates inside a hydrothermally synthesized coating.