Effects Of Surface Modification On Biocompatibility Of Magnesium Alloy AZ811

Objeetives:To evaluate the effects of micro-arc oxidation (MAO) and poly-L-lactic acid (PLLA) surface-modification on the corrosion resistance, cytotoxicity, blood compatibility and general toxicity of magnesium alloy AZ811.Methods:Micro-arc oxidation surface-modificated AZ811(MAO/AZ811) materials and MAO+poly-L-lactic acid (PLLA) surface-modificated AZ811 (MAO+PLLA/ AZ811) materials were prepared, the surface topography of materials in the physiological environment in vitro was observed by scanning electron microscopy (SEM). The human Umbilical Artery Smooth muscle cells (HUASMCs) and the human umbilical vein endothelial cells (HUVECs) were treated by leaching liquor of materials, the relative growth rate (RGR) was assessed by MTT assay to evaluate the level of cytotoxicity. Micro-arc oxidation surface-modificated AZ811(MAO/AZ811) materials and MAO+poly-L-lactic acid (PLLA) surface-modificated AZ811 (MAO+PLLA/AZ811) materials were prepared, coagulation time (PT, RT) and hemolytic ratio were determined to evaluate the blood compatibility of those materials. Acute toxicity test and subacute toxicity test were performed on Kunming mice with leaching liquor of MAO/AZ811 and MAO+PLLA/AZ811 materials, then the biochemical indicatorswere and the pathological change of liver were checked after 4 weeks.Results:The observation of scanning electron microscopy indicated that AZ811 corroded seriously after immersion and there was no apparent obvious corrosion holes on the the surface of MAO/AZ811 and MAO+PLLA/AZ811 materials after immersion. HUASMCs and HUVECs showed normal Proliferation and morphology, the cytotoxieity of AZ811 Magnesium alloy made from MAO and MAO+PLLA was 1 grade. It was found that there were good anticoagulant properties but lower hemolysis rate of MAO/AZ811 and MAO+PLLA/AZ811 materials. There was no significant abnormality found in biochemical indicators and pathological analysis in acute toxicity test and subacute toxicity test.Conclusion:MAO and MAO+PLLA surface modification improved the corrosion resistance of AZ811 magnesium alloy. It was found that there were no apparent cytotoxicity of MAO/AZ811 and MAO+PLLA/AZ811 materials. MAO and MAO+PLLA surface modification improved the blood compatibility of AZ811 magnesium alloy. It was found that there were no apparent general toxicity of MAO/AZ811 and MAO+PLLA/AZ811 materials.