Department of Orthopedics, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, 200072, P. R. China.
Department of Physics, Department of Materials Science and Engineering and Department of Biomedical Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, 999077, P. R. China.
Adv Mater. 2023 May;35(19):e2212315. doi: 10.1002/adma.202212315. Epub 2023 Mar 22.
Physical disruption is an important antibacterial means as it is lethal to bacteria without spurring antimicrobial resistance. However, it is very challenging to establish a quantifiable relationship between antibacterial efficacy and physical interactions such as mechanical and electrical forces. Herein, titanium nitride (TN) nanowires with adjustable orientations and capacitances are prepared to exert gradient electro-mechanical forces on bacteria. While vertical nanowires show the strongest mechanical force resulting in an antibacterial efficiency of 0.62 log reduction (vs 0.22 for tiled and 0.36 for inclined nanowires, respectively), the addition of electrical charges maximizes the electro-mechanical interactions and elevates the antibacterial efficacy to more than 3 log reduction. Biophysical and biochemical analyses indicate that electrostatic attraction by electrical charge narrows the interface. The electro-mechanical intervention more easily stiffens and rips the bacteria membrane, disturbing the electron balance and generating intracellular oxidative stress. The antibacterial ability is maintained in vivo and bacteria-challenged rats are protected from serious infection. The physical bacteria-killing process demonstrated here can be controlled by adjusting the electro-mechanical interactions. Overall, these results revealed important principles for rationally designing high-performance antibacterial interfaces for clinical applications.
物理破坏是一种重要的抗菌手段，因为它对细菌具有致死作用，而不会刺激抗菌耐药性的产生。然而，建立抗菌功效与机械和电力等物理相互作用之间可量化的关系非常具有挑战性。在此，制备了具有可调取向和电容的氮化钛 (TN) 纳米线，以对细菌施加梯度机电力。垂直纳米线显示出最强的机械力，导致抗菌效率降低 0.62 对数（分别为平铺纳米线的 0.22 和倾斜纳米线的 0.36），而电荷的加入则最大限度地提高了机电相互作用，使抗菌效率提高了 3 个多对数以上。生物物理和生物化学分析表明，电荷的静电吸引力缩小了界面。机电干预更容易使细菌膜变硬和撕裂，扰乱电子平衡并产生细胞内氧化应激。在体内，抗菌能力得以维持，受细菌感染的大鼠得到保护，免受严重感染。这里展示的物理杀菌过程可以通过调整机电相互作用来控制。总的来说，这些结果为临床应用中合理设计高性能抗菌界面提供了重要原则。
