Effect of polyvinyl alcohol concentration on biomedical application of chitosan/bioactive glass composite coated on AZ91D magnesium alloy

The aim of this work is to improve the biomedical properties of AZ91D magnesium by coating it with polyvinyl alcohol (PVA), bioactive glass (BG), and natural chitosan (CH), using the electrophoretic deposition (EPD) method with different PVA concentrations (15%, 20%, and 25%). The composites were characterized by X-ray diffraction (XRD), furrier infrared spectroscopy (FTIR), and scanning electron microscopy (SEM), which showed uniformity on the surface. Bio-corrosion activities were investigated by polarization tests in phosphate buffer saline (PBS) solution, which indicated that a composite with 15% PVA has lower corrosion resistance than base metal due to the weakness of the composite coating and applied current in the EPD process. The higher corrosion resistance was observed in the 25% PVA concentration due to the presence of a higher amount of PVA in the applied composite (which induces a denser and thicker composite coating). An in vitro bioactivity test was performed in PBS solution, which showed that more hydroxyapatite was formed on the surface by increasing PVA concentration. Furthermore, adhesive analysis of composite coatings indicates that by increasing the PVA concentration in composites, more adhesivity is obtained (5%, 12%, and 30%, respectively).