Polyelectrolytes fabrication on magnesium alloy surface by layer-by-layer assembly technique with antiplatelet adhesion and antibacterial activities

Magnesium alloy (MgA) was widely used in biomedical field owing to its good biocompatibility and degradability. The surface of MgA was usually modified to improve its corrosion resistance, biocompatibility, and biological properties. Herein, we employed a layer-by-layer assembly technique to assemble both polyanionic and polycationic electrolytes onto the microarc oxidation-treated MgA surface to yield MgA-MgO-PEI-[Ge(HANPs)/Lzm]₅₀, where the gelatin-conjugated hydroxyapatite nanoparticles [Ge(HANPs)] are the polyanionic electrolyte, lysozyme (Lzm) is the polycationic electrolyte, and polyethyleneimine (PEI) is the transition layer. The morphology and chemical composition of MgA-MgO-PEI-[Ge(HANPs)/Lzm]₅₀ were characterized by X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy, indicating that [Ge(HANPs)/Lzm]₅₀ were successfully fabricated on the surface of MgA-MgO. The surface of MgA-MgO-PEI-[Ge(HANPs)/Lzm]₅₀ exhibited good hydrophilicity as evidenced by the low water contact angle of 24.5°. Excellent corrosion resistance of MgA-MgO-PEI-[Ge(HANPs)/Lzm]₅₀ was obtained since it can decrease about four orders of magnitude of corrosive current (I_corr) compared to pristine MgA. The biological assay for MgA-MgO-PEI-[Ge(HANPs)/Lzm]₅₀ showed good antiplatelet adhesion and excellent antibacterial activities against both E. coli and S. aureus.