Qu Chuang, Rozsa Jesse, Running Mark, McNamara Shamus, Walsh Kevin
Department of Electrical and Computer Engineering, University of Louisville, Louisville, KY, 40292, USA.
Department of Biology, University of Louisville, Louisville, KY, 40292, USA.
Discov Nano. 2024 Jan 25;19(1):17. doi: 10.1186/s11671-024-03959-0.
The paper uses inverted glancing angle deposition (I-GLAD) for creating antibacterial surfaces. Antibacterial surfaces are found in nature, such as on insect wings, eyes, and plant leaves. Since the bactericidal mechanism is purely physical for these surfaces, the antimicrobial resistance of bacteria to traditional chemical antibiotics can be overcome. The technical problem is how to mimic, synthesize, and scale up the naturally occurring antibacterial surfaces for practical applications, given the fact that most of those surfaces are composed of three-dimensional hierarchical micro-nano structures. This paper proposes to use I-GLAD as a novel bottom-up nanofabrication technique to scale up bio-inspired nano-structured antibacterial surfaces. Our innovative I-GLAD nanofabrication technique includes traditional GLAD deposition processes alongside the crucial inverting process. Following fabrication, we explore the antibacterial efficacy of I-GLAD surfaces using two types of bacteria: Escherichia coli (E. coli), a gram-negative bacterium, and Staphylococcus aureus (S. aureus), a gram-positive bacterium. Scanning electron microscopy (SEM) shows the small tips and flexible D/P (feature size over period) ratio of I-GLAD nanoneedles, which is required to achieve the desired bactericidal mechanism. Antibacterial properties of the I-GLAD samples are validated by achieving flat growth curves of E. coli and S. aureus, and direct observation under SEM. The paper bridges the knowledge gaps of seeding techniques for GLAD, and the control/optimization of the I-GLAD process to tune the morphologies of the nano-protrusions. I-GLAD surfaces are effective against both gram-negative and gram-positive bacteria, and they have tremendous potentials in hospital settings and daily surfaces.
本文采用倾斜掠角沉积（I-GLAD）技术制备抗菌表面。自然界中存在抗菌表面，如昆虫翅膀、眼睛和植物叶片上的表面。由于这些表面的杀菌机制纯粹是物理性的，因此可以克服细菌对传统化学抗生素的耐药性。技术问题在于，鉴于大多数天然抗菌表面由三维分级微纳结构组成，如何模仿、合成并扩大这些表面以用于实际应用。本文提出使用I-GLAD作为一种新型的自下而上的纳米制造技术，以扩大受生物启发的纳米结构抗菌表面的规模。我们创新的I-GLAD纳米制造技术包括传统的GLAD沉积工艺以及关键的反转工艺。制备完成后，我们使用两种细菌来探究I-GLAD表面的抗菌效果：革兰氏阴性菌大肠杆菌（E. coli）和革兰氏阳性菌金黄色葡萄球菌（S. aureus）。扫描电子显微镜（SEM）显示了I-GLAD纳米针的小尖端和灵活的D/P（特征尺寸与周期之比），这是实现所需杀菌机制所必需的。通过获得大肠杆菌和金黄色葡萄球菌的平坦生长曲线以及SEM下的直接观察，验证了I-GLAD样品的抗菌性能。本文弥补了GLAD播种技术以及I-GLAD工艺控制/优化以调整纳米突起形态方面的知识空白。I-GLAD表面对革兰氏阴性菌和革兰氏阳性菌均有效，并且在医院环境和日常表面中具有巨大潜力。
