Department of Biomass and Leather Engineering, Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University, Chengdu 610065, PR China.
Department of Chemistry, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong.
Mater Sci Eng C Mater Biol Appl. 2019 Jun;99:344-356. doi: 10.1016/j.msec.2019.01.119. Epub 2019 Jan 27.
Surface modification of biomedical Mg with functional polymers coatings is an effective and simple strategy to improve the corrosion resistance and anti-bacterial property. Herein, we develop a novel biodegradable and anti-bacterial polymer coating for Mg rods. A key feature of our approach is to treat the Mg rods with polyurethane, a widely used coating material with strong structural controllability and good film-formation property. Polyurethanes (PU) functionalized by polyethylene glycol (PEG) chains (GPU) and zwitterions (ZPU) were firstly synthesized and subsequently applied to fabricate coatings on Mg-based rods. Scanning electron microscopy (SEM) result demonstrates that a homogeneous and dense layer with a thickness of ~4-15 μm is readily formed on the substrates by dip-coating method. We first investigated how PU coatings would affect their resulting corrosion behaviors by the electrochemical corrosion test, surface morphology examining and element analysis of the immersed samples. Then, we evaluated their protection capabilities and the relationship to Mg ion release and pH value alteration under the physiological conditions. Results show that the corrosion resistance of Mg rods is improved appreciably after coating with the synthesized PU polymers. More importantly, the functionalized PU exhibit enhanced antibacterial performance and excellent blood compatibility. In particular, ZPU-12 not only successfully improves the corrosion resistance of substrates, but also produces an antimicrobial coating for preventing bacterial attachment. The application of these functionalized PU coatings for the surface modification of biomedical Mg-based alloys can provide a practical and potential strategy to expedite their clinical acceptance.
对生物医学镁进行功能聚合物涂层表面改性是一种提高耐腐蚀性和抗菌性能的有效且简单的策略。在此，我们为镁棒开发了一种新型的可生物降解和抗菌聚合物涂层。我们方法的一个关键特点是用聚氨酯处理镁棒，聚氨酯是一种具有强结构可控性和良好成膜性能的广泛使用的涂层材料。首先合成了由聚乙二醇（PEG）链（GPU）和两性离子（ZPU）官能化的聚氨酯（PU），并随后将其应用于通过浸涂法在镁基棒上制备涂层。扫描电子显微镜（SEM）结果表明，通过浸涂法在基底上容易形成厚度约为 4-15 μm 的均匀且致密的层。我们首先通过电化学腐蚀试验、浸入样品的表面形貌检查和元素分析来研究 PU 涂层如何影响其腐蚀行为。然后，我们在生理条件下评估了它们的保护能力以及与镁离子释放和 pH 值变化的关系。结果表明，用合成的 PU 聚合物涂覆后，镁棒的耐腐蚀性得到了显著提高。更重要的是，功能化的 PU 表现出增强的抗菌性能和优异的血液相容性。特别是，ZPU-12 不仅成功地提高了基底的耐腐蚀性，而且还产生了一种抗菌涂层，可防止细菌附着。这些功能化 PU 涂层在生物医学镁基合金表面改性中的应用为加速其临床应用提供了一种实用且有潜力的策略。
