银−沸石掺杂羟基磷灰石镁合金涂层的生物活性、体外腐蚀行为和抗菌活性

摘要

Mg-based alloys received significant attention for temporary implant applications while, their applications have been limited by high degradation rate. Therefore, silver?zeolite doped hydroxyapatite (Ag?Zeo?HAp) coating was synthesized on TiO2-coated Mg alloy by physical vapour deposition (PVD) assisted electrodeposition technique to decrease the degradation rate of Mg alloy. X-ray diffraction (XRD) analysis and field emission scanning electron microscopy (FE-SEM) images showed the formation of a uniform and compact layer of Ag?Zeo?HAp with a thickness of 15 μm on the TiO2 film with a thickness of 1 μm. The potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) tests indicated that corrosion resistance of Mg?Ca alloy was considerably increased by the Ag?Zeo?HAp coating. The bioactivity test in the simulated body fluid (SBF) solution showed that a dense and homogeneous bonelike apatite layer was formed on the Ag?Zeo?HAp surface after 14 d. Investigation of antibacterial activity via disk diffusion and spread plate methods showed that the Ag?Zeo?HAp coating had a significantly larger inhibition zone (3.86 mm) towards Escherichia coli (E. coli) compared with the TiO2-coated Mg alloy (2.61 mm). The Ag?Zeo?HAp coating showed high antibacterial performance, good bioactivity, and high corrosion resistance which make it a perfect coating material for biomedical applications.%镁基合金作为临时植入材料的应用受到了越来越多的关注,然而,由于其降解速率高,因此应用受到了限制.为了降低镁合金的降解速率,本文作者采用物理气相沉积(PVD)辅助电沉积技术在镀氧化钛(TiO2)的镁合金上涂覆掺银?沸石羟基磷灰石(Ag?Zeo?HAp)涂层.X射线衍射(XRD)分析和场发射扫描电镜(FESEM)图片显示,在厚度约为1μm的二氧化钛薄膜上形成了均匀且致密的Ag?Zeo?HAp涂层,厚度约为15μm.动电位极化(PDP)和电化学阻抗谱(EIS)测试表明,通过Ag?Zeo?HAp涂层,Mg?Ca合金的耐腐蚀性大大提高.模拟体液(SBF)浸泡测试生物活性试验结果表明,在14 d后的Ag?Zeo?HAp表面上形成了一层致密且均匀的类骨磷灰石层.采用琼脂扩散法和平板涂布法对抗菌活性进行研究.结果表明,与TiO2涂层的镁合金(2.61 mm)相比,Ag?Zeo?HAp涂层对大肠杆菌(E.coli)的抑制区(3.86 mm)明显增大.Ag?Zeo?HAp涂层具有良好的抗菌性能、良好的生物活性和耐腐蚀性,是生物医学应用的理想涂层材料.