Electrophoretic deposited boron nitride nanosheets-containing chitosan-based coating on Mg alloy for better corrosion resistance, biocompatibility and antibacterial properties

To reduce the degradation of magnesium alloy, improve its antibacterial activity, and fulfil specific requirements for bone implant material applications, a chitosan (CS)/boron nitride nanosheet (BNNS) composite coating was constructed on the surface of Mg–Zn–Y–Nd–Zr alloy via electrodeposition. The results show that BNNS was uniformly embedded and significantly changed the morphology and roughness of the CS coating. Electrochemical and immersion tests suggest that the CS–BNNS composite coating can effectively provide a long-term protection to the substrate. The antibacterial activity results show that BNNS significantly improved the antibacterial activity of the CS coating against E. coli and S. aureus, and verified the sterilisation mechanism of BNNS in contact with bacterial membranes. Meanwhile, cytocompatibility tests showed that the CS–BNNS coating has no adverse effect on the adhesion and proliferation of mouse osteoblasts cells. Thus, the fabricated CS–BNNS composite coating could be a promising application in surface modification for Mg-based bone implants. In this study, a chitosan (CS)/boron nitride nanosheet (BNNS) composite coating was constructed on a magnesium (Mg) alloy via electrodeposition. The CS–BNNS coating improves the antibacterial activity and reduces the degradation rate of the Mg alloy. BNNS was uniformly embedded into the chitosan coating, which significantly improved the bactericidal activity of the CS coating. Meanwhile, cytocompatibility tests showed that the CS–BNNS coating has no adverse effect on the adhesion and proliferation of mouse osteoblasts cells. [Display omitted] •CS–BNNS coatings were synthesised on a Mg alloy via electrodeposition.•CS-BNNS coating reduces the degradation rate of Mg alloy.•CS-BNNS coating improves the antibacterial activity of Mg alloy.