不同镁合金支架材料MAO/PLLA复合膜研究

Research of MAO/PLLA Composite Coating on Different Magnesium Alloy Stent Materials

摘要:

两种系列的镁合金WE42与AM20微弧氧化（MAO）后用浸渍法对微弧氧化膜进行聚乳酸（PLLA）封孔处理制备复合涂层，通过扫描电镜（SEM）分析微弧氧化膜及聚乳酸封孔膜的表面形貌及结构，X射线衍射（XRD）分析微弧氧化膜的主要成分为MgSiO3和SiO2，通过腐蚀失重测定试样的失重率。在37 ℃的hank’s模拟体液中测定电化学阻抗(EIS)曲线，表明采用生物相容性好的PLLA有效的填充了微弧氧化膜表面的微孔，通过阻挡腐蚀离子扩散提高了镁合金的耐腐蚀性，同时制备生物相容性涂层，对于提高生物可吸收镁合金血管支架的性能具有重要意义。

Abstract:

Micro-arc oxidation (MAO) layers which were prepared on magnesium alloy WE42 and AM20 by MAO were sealed with PLLA by immersion technique to get composite coatings. The microstructure of the MAO coatings and the composite coatings were analyzed by scanning electron microscopy. The composition of MAO coating is MgSiO3 and SiO2 by X-ray diffractometer (XRD) and the rate of mass loss were tested by immersion test. Electrochemical impedance spectroscopy (EIS) shows that PLLA coating seals the pores in the MAO coating and improves the corrosion resistance by preventing the corrosive ions from diffusing to the magnesium alloy substrate. This composite coating is of high biocompatibility so it is of significance to improve the property of bioabsorbable magnesium stent.