Because of unique properties such as the lightweight, natural biodegradability, and biocompatibility, magnesium alloys are promising in biomedical implants. However, inadequate corrosion resistance in the physiological environment remains a technical hurdle and application of coatings is a viable means to overcome the deficiency. Also, the antibacterial properties are very important in order to mitigate post-implantation complications arising from bacterial infection. In this study, a biocompatible silk film is deposited on AZ31 Mg alloy to enhance the corrosion resistance and by means of oxygen plasma etching, nature-inspired nanopatterns are fabricated on the surface of the silk film to improve the inherent antibacterial properties. The biocompatibility and antibacterial properties are determined with MC3T3-E1 osteoblast cells and E. coli and S. aureus, respectively. The antimicrobial properties of the silk coated AZ31 are better than those of the bare alloy probably due to the combined effects of the nanopatterns and alkalinity associated with leaching of Mg ions. The β-sheets formed on the silk film is found to result in 10⁴ times reduction in the corrosion current density and 50% reduction in Mg leaching after 1 day. Although degradation of the β-sheets is observed to begin after 1 day, the amount of Mg ions leached to the medium from silk-coated AZ31 is still 17% lower than that from the bare one. The biomimicking nanopatterns on the natural silk film improve the corrosion resistance, biocompatibility, and antibacterial properties simultaneously and have large clinical potential.

由于镁合金具有重量轻，天然可生物降解和生物相容性等独特特性，因此有望用于生物医学植入物中。然而，在生理环境中耐腐蚀性不足仍然是技术障碍，并且涂层的应用是克服该缺陷的可行手段。同样，抗菌特性对于减轻细菌感染引起的植入后并发症非常重要。在这项研究中，将生物相容性丝膜沉积在AZ31 Mg合金上以增强耐腐蚀性，并通过氧等离子体蚀刻，在丝膜表面上制作出具有自然灵感的纳米图案，以提高固有的抗菌性能。用MC3T3-E1成骨细胞确定生物相容性和抗菌性能。分别为大肠杆菌和金黄色葡萄球菌。丝线涂层的AZ31的抗菌性能比裸露的合金好，这可能是由于纳米图案与Mg离子浸出相关的碱度的综合作用所致。发现在丝膜上形成的β片层导致腐蚀电流密度降低10 ⁴倍，并且在1天后Mg浸出降低50％。尽管观察到β-片层的降解在1天后开始，但是从丝被涂覆的AZ31浸出到培养基中的Mg离子的量仍然比从裸露的镁离子中浸出的Mg离子的量低17％。天然丝膜上的仿生物纳米图案可同时提高耐腐蚀性，生物相容性和抗菌性能，并具有很大的临床潜力。