Institute for Materials Science - Multicomponent Materials, Christian-Albrechts University at Kiel, Kaiserstr. 2, 24143 Kiel, Germany.
Mater Sci Eng C Mater Biol Appl. 2013 May 1;33(4):2367-75. doi: 10.1016/j.msec.2013.01.069. Epub 2013 Feb 5.
A silver containing coating used in the human body, e.g., on an implant should be both effectively antimicrobial and non-cytotoxic to human cells. It is generally believed that the biologic effect originates from silver ions released from the coating. Nanocomposites with well controlled Ag filling factor were prepared by co-sputtering, and the silver surface concentration and the silver release were determined by XPS and ICP-MS, respectively. Here we show that only a small therapeutic window exists for dissolved silver but the therapeutic window is largely increased at the surface. While the toxicity observed for mammalian cells in contact with the bioactive Ag/TiO2 nanocomposite surface and for silver ions in solution is rather similar the antimicrobial activity is drastically enhanced at the surface. A model is proposed to explain the strong increase of the antimicrobial activity at the surface. The present results not only question well-established tests for antimicrobial activity but they are also important for the design of antimicrobial coatings, e.g., for biomedical devices.
一种用于人体的含银涂层，例如在植入物上，应该既具有有效的抗菌作用，又对人体细胞无毒。人们普遍认为，这种生物效应源自涂层释放的银离子。通过共溅射制备了具有良好控制的 Ag 填充因子的纳米复合材料，并通过 XPS 和 ICP-MS 分别测定了银表面浓度和银释放量。在这里，我们表明，只有很小的治疗窗口存在于溶解的银中，但在表面上，治疗窗口大大增加。虽然与生物活性的 Ag/TiO2 纳米复合材料表面接触的哺乳动物细胞的毒性和溶液中的银离子相当相似，但抗菌活性在表面上大大增强。提出了一个模型来解释表面抗菌活性的大幅增强。这些结果不仅对现有的抗菌活性测试提出了质疑，而且对抗菌涂层的设计也很重要，例如用于生物医学设备的抗菌涂层。
