Preparing a Bioactive (Chitosan/Sodium Hyaluronate)/SrHA Coating on Mg-Zn-Ca Alloy for Orthopedic Implant Applications

The uncontrollable rapid degradation rate of the Mg alloy substrate limited its clinical application, and implant-associated infections have been reported to be the main reason for the secondary surgery of orthopedic implantation. The aim of this study was to produce a multifunctional coating on magnesium-based alloys that have improved corrosion resistance, bioactivity, and antibacterial properties through the preparation of polyelectrolytic multilayers (PEMs) consisting of chitosan (CS) and sodium hyaluronate (HA) on silane-modified strontium-substituted hydroxyapatite (hereafter referred to as Bil (SH + CS)/SrHA). The multifunctional coatings were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The results showed the polyelectrolyte complex SH/CS layer to be uniformly and tightly attached on to the surface of silane-treated SrHA. At the same time, a potentiodynamic polarization test and hydrogen evolution test showed the Bil (SH + CS)/SrHA coatings to exhibit superior corrosion resistance than bulk Mg-based alloys. The results of the cell-surface interactions revealed Bil (SH + CS)/SrHA coatings to be in favor of cell initial adhesion and more beneficial to the proliferation and growth of cells with the processing of co-culture. In addition, antibacterial tests demonstrated the strong bactericidal effect of Bil (SH + CS)/SrHA coatings against both Escherichia coli (E. coli) and Staphylococcus (S. aureus), suggesting that Bil (SH + CS)/SrHA coatings can successfully achieve multifunctionality with enhanced corrosion resistance, biocompatibility, and antibacterial properties.

Automated summary

This study aimed to produce a multifunctional coating on magnesium-based alloys that have improved corrosion resistance, bioactivity, and antibacterial properties. The results showed that the coatings exhibited superior corrosion resistance, promoted cell adhesion and proliferation, and had strong bactericidal effects.