State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 200050, China.
Biomater Sci. 2020 Mar 31;8(7):1815-1829. doi: 10.1039/c9bm01793c.
Multifarious strategies have been proposed to enhance the antibacterial ability of implant surfaces for preventing bacterial infection, however, developing facile and universal modification methods still remains extremely elusive. Herein, inspired by the fact that the electron transfer respiratory chain of bacteria is embedded in the membrane, we proposed a novel strategy of local alkalinity disturbing bacterial respiration to endow implant materials with antibacterial ability. As a demonstration, MgO was deposited on biomedical titanium via magnetron sputtering to regulate surface alkalinity. With the thickness of MgO films increasing, they exhibited an excellent antibacterial rate against both Gram-negative and positive bacteria. The antibacterial mechanism confirmed that the alkaline surface can disturb the bacterial respiration action via weakening the transmembrane proton concentration gradient, resulting in the blockage of energy metabolism and the increase of oxidative stress of bacteria. Cell experiments indicated that MgO films not only have no obvious cytotoxicity to osteoblast cells, but can also selectively kill bacteria and promote cell proliferation in the presence of both bacteria and cells. More importantly, the by-product of MgO was only the biocompatible Mg2+, reducing any concerns about potential toxic effects. Furthermore, sputtering alkaline MgO films was confirmed to work well on polyetheretherketone polymer and zirconia ceramic implants, which indicates that this strategy has broad prospects of clinical application for preventing implant-associated bacterial infection.
已经提出了多种策略来增强植入物表面的抗菌能力，以预防细菌感染，然而，开发简单且通用的修饰方法仍然极其困难。受细菌电子传递呼吸链嵌入在膜中的事实的启发，我们提出了一种通过局部破坏细菌呼吸来赋予植入材料抗菌能力的新策略。作为一个例子，通过磁控溅射在生物医学钛上沉积了氧化镁，以调节表面碱性。随着氧化镁薄膜厚度的增加，它们对革兰氏阴性菌和阳性菌都表现出了优异的抗菌率。抗菌机制证实，碱性表面可以通过削弱跨膜质子浓度梯度来干扰细菌呼吸作用，从而阻断能量代谢并增加细菌的氧化应激。细胞实验表明，氧化镁薄膜不仅对成骨细胞没有明显的细胞毒性，而且在细菌和细胞共存的情况下，还可以选择性地杀死细菌并促进细胞增殖。更重要的是，氧化镁的副产物只是生物相容性的 Mg2+，减少了对潜在毒性影响的担忧。此外，证实溅射碱性氧化镁薄膜在聚醚醚酮聚合物和氧化锆陶瓷植入物上效果良好，这表明该策略在预防植入物相关细菌感染方面具有广阔的临床应用前景。
