Constructing a functional hybrid coating appears to be a promising strategy for addressing the poor corrosion resistance and insufficient endothelialization of Mg-based stents. Nevertheless, the steps for preparing composite coatings are usually complicated and time-consuming. Herein, a novel composite coating, composed of bioactive magnesium thioctic acid (MTA) layer formed by deposition and corrosion-resistant magnesium hydroxide (Mg(OH)) layer grown in situ, is simply fabricated on ZE21B alloys via one-step electrodeposition. Scanning electron microscopy (SEM) shows that the electrodeposited coating has a compact and uniform structure. And the high adhesion of the MTA/Mg(OH) hybrid coating is also confirmed by the micro-scratch test. Electrochemical test, scanning kelvin probe (SKP), and hydrogen evolution measurement indicate that the hybrid coating effectively reduces the degradation rate of Mg substrates. Haemocompatibility experiment and cell culture trial detect that the composite coating is of fine biocompatibility. Finally, the preparation mechanism of MTA/Mg(OH) hybrid coatings is discussed and proposed. This coating shows a great potential application for cardiovascular stents.

中文翻译：

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心血管支架ZE21B合金上一步电沉积硫辛酸镁/氢氧化镁混合涂层的降解和生物相容性

构建功能性混合涂层似乎是解决镁基支架耐腐蚀性差和内皮化不足问题的一种有前途的策略。然而，制备复合涂层的步骤通常复杂且耗时。在此，通过一步电沉积在ZE21B合金上简单地制备了一种新型复合涂层，该涂层由沉积形成的生物活性硫辛酸镁（MTA）层和原位生长的耐腐蚀氢氧化镁（Mg（OH））层组成。扫描电子显微镜（SEM）显示电沉积涂层具有致密、均匀的结构。微划痕测试也证实了MTA/Mg(OH)杂化涂层的高附着力。电化学测试、扫描开尔文探针（SKP）和析氢测量表明，混合涂层有效降低了镁基体的降解率。血液相容性实验和细胞培养试验表明复合涂层具有良好的生物相容性。最后，讨论并提出了MTA/Mg(OH)杂化涂层的制备机理。这种涂层在心血管支架方面显示出巨大的应用潜力。