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To enhance corrosion resistance and hemocompatibility of magnesium alloy (Mg alloy), poly(ethylene glycol) methacrylate (PEGMA) was covalently bonded to micro-arc oxidation treated Mg alloy substrate via thiol-ene photochemistry using self-assembled (3-mercaptopropyl)trimethoxysilane film as spacer. Chemical composition of the modified surfaces was verified by attenuated total reflection Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy analysis and X-ray diffraction. Scanning electronic microscopy was used to show morphologies of the samples at different stages. Results of water contact angle measurement showed that the hydrophilicity of the surface has improved significantly after surface modification. Potentiodynamic polarization, electrochemical impedance spectroscopy and hydrogen evolution test demonstrated that corrosion resistance increased significantly for modified Mg alloy versus unmodified surfaces. In the meantime, the surface bonding of PEGMA imparted anti-platelet adhesion compared to the Mg alloy surface, displaying excellent hemocompatibility. This composite coating technique gives promise in acutely reducing both the corrosion and platelet adhesion, making it attractive for application to blood contacting material, such as vascular stents, made from degradable Mg alloys. [ABSTRACT FROM AUTHOR]

Functionalization of magnesium alloy (Mg alloy) with multiple bioactivities is desired to obtain surfaces with improved biocompatibility and antibacterial property. In this article, an anticorrosive and antimicrobial coating was prepared on Mg alloy surface by layer-by-layer (LbL) assembly of polyelectrolytes. A polycationic copolymer (P(DOP- co -DMAEMA + )) bearing dopamine (DOP) and 2-(methacryloxy)ethyl trimethylammonium chloride (DMAEMA + ) was synthesized and deposited on the surface of micro-arc oxidation (MAO) treated Mg alloy substrate as the first layer. The presence of DOP units ensure a strong anchoring on Mg alloy substrate, and the –N + (CH 3 ) 3 groups are sources of positive charge, providing electrostatic interaction with polyanion electrolyte. Negatively charged colloidal silver particles were prepared by using dextran sulfate (DS) as a stabilizer to precede chemical reduction by dextrose and served as a polyanion electrolyte. The functional polyelectrolyte multilayered films were obtained by alternating deposition P(DOP- co -DMAEMA + ) and DS-stabilized silver colloid (DS-Ag) in a spin-assisted LbL assembly manner. The prepared nanosized silver colloids and functionalized Mg alloy were characterized by ultraviolet–visible (UV–vis) spectroscopy, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Potentiodynamic polarization test confirmed that corrosion resistance of modified Mg alloy significantly increased and the fabricated polyelectrolyte multilayer films showed significant antibacterial activity. [ABSTRACT FROM AUTHOR]

To improve corrosion resistance and hemocompatibility of magnesium alloy (Mg alloy), a polymerized 2-methacryloyloxyethyl phosphorycholine (PMPC) coating was fabricated via surface thiol-ene photopolymerization onto Mg alloy treated by cathodic plasma electrolytic deposition (CPED). Surface morphology, chemical composition and phase composition of CPED layer and CPED/PMPC composite coating were investigated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), respectively. Potentiodynamic polarization test and electrochemical impedance spectroscopy (EIS) illustrated that the corrosion resistane of Mg alloy in simulated body fluid (SBF) was significantly enhanced after the formation of CPED/PMPC composite coating. Platelets adhesion measurement indicated that CPED/PMPC treated Mg alloy possesses promising hemocompatibility. The approach presented here affords an effective alternative for surface modification of Mg alloy to meet the requirements of vascular scaffold materials. [ABSTRACT FROM AUTHOR]