High Aspect Ratio Nanostructures Kill Bacteria via Storage and Release of Mechanical Energy
High Aspect Ratio Nanostructures Kill Bacteria via Storage and Release of Mechanical Energy
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DOI：
10.1021/acsnano.8b01665
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发表时间：
2018-07-01
期刊：
影响因子：
17.1
通讯作者：
Ivanova, Elena P.
中科院分区：
文献类型：
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作者：
Linklater, Denver P.;De Volder, Michael;Ivanova, Elena P.
由于抗药性细菌引起的无法治愈的感染数量在全球范围内增加，这一威胁要求设计和制造新一代杀菌材料。在这里，我们报告了一个概念的抗菌表面的设计，从而细胞死亡的结果，从能力的纳米功能偏转时，与附着的细胞接触。我们表明，使用三维透射电子显微镜，特别高的纵横比（100-3000）的垂直排列的碳纳米管（VACNTs）赋予极高的灵活性，这增强了弹性能量存储在碳纳米管，因为它们弯曲与细菌接触。我们的实验和理论分析表明，对于高纵横比的结构，存储在碳纳米管的弯曲能量是一个重要的因素，为革兰氏阳性和革兰氏阴性细菌的物理破裂。最高的杀菌率（99.3%的铜绿假单胞菌和84.9%的金黄色葡萄球菌）是通过修改长度的VACNTs，使我们能够确定最佳的基质性能，有效地杀死不同类型的细菌。这项工作强调了高纵横比纳米特征的杀菌活性可以胜过天然杀菌表面和先前研究中报道的其他合成纳米结构多功能表面。本系统显示出迄今为止报道的基于CNT的基质对革兰氏阴性细菌的最高杀菌活性，表明在基于VACNT的基质上实现接近100%细菌灭活的可能性。
The threat of a global rise in the number of untreatable infections caused by antibiotic-resistant bacteria calls for the design and fabrication of a new generation of bactericidal materials. Here, we report a concept for the design of antibacterial surfaces, whereby cell death results from the ability of the nanofeatures to deflect when in contact with attaching cells. We show, using three-dimensional transmission electron microscopy, that the exceptionally high aspect ratio (100-3000) of vertically aligned carbon nanotubes (VACNTs) imparts extreme flexibility, which enhances the elastic energy storage in CNTs as they bend in contact with bacteria. Our experimental and theoretical analyses demonstrate that, for high aspect ratio structures, the bending energy stored in the CNTs is a substantial factor for the physical rupturing of both Gram-positive and Gram-negative bacteria. The highest bactericidal rates (99.3% for Pseudomonas aeruginosa and 84.9% for Staphylococcus aureus) were obtained by modifying the length of the VACNTs, allowing us to identify the optimal substratum properties to kill different types of bacteria efficiently. This work highlights that the bactericidal activity of high aspect ratio nanofeatures can outperform both natural bactericidal surfaces and other synthetic nanostructured multifunctional surfaces reported in previous studies. The present systems exhibit the highest bactericidal activity of a CNT-based substratum against a Gram-negative bacterium reported to date, suggesting the possibility of achieving close to 100% bacterial inactivation on VACNT-based substrata.