Deokar Archana R, Lin Lih-Yuan, Chang Chun-Chao, Ling Yong-Chien
Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan.
J Mater Chem B. 2013 May 28;1(20):2639-2646. doi: 10.1039/c3tb20188k. Epub 2013 Apr 23.
Development of carbon nanotubes toward commercial antibacterial applications warrants the understanding of their interaction mechanism with bacterial cells. The antibacterial activity and mechanism of acid-functionalized single-walled carbon nanotube (AFSWCNT) coated paper was assessed for gram-positive Staphylococcus aureus and gram-negative Escherichia coli models of bacteria. Better activity towards gram-positive bacteria was observed, whereas the presence of an outer membrane makes gram-negative bacteria more resistant to cell membrane damage caused by AFSWCNTs. Based on measured cytoplasmic efflux materials of bacteria, X-ray photoelectron spectroscopy, and scanning transmission electron microscopy combined with electron energy-loss spectroscopy imaging studies, we found that the better antibacterial activity of AFSWCNTs toward gram-positive bacteria is attributed to not only direct physical contact and piercing action, but also molecular-scale interaction with surface functional groups of bacteria. The novel antibacterial mechanism of AFSWCNTs might bring a promising strategy to design new antibacterial materials against drug-resistant bacteria species.
碳纳米管在商业抗菌应用方面的发展需要了解其与细菌细胞的相互作用机制。针对革兰氏阳性金黄色葡萄球菌和革兰氏阴性大肠杆菌这两种细菌模型，评估了酸功能化单壁碳纳米管（AFSWCNT）涂层纸的抗菌活性及机制。观察到其对革兰氏阳性菌有更好的活性，而外膜的存在使革兰氏阴性菌对AFSWCNTs引起的细胞膜损伤更具抗性。基于对细菌胞质流出物质的测定、X射线光电子能谱以及结合电子能量损失谱成像研究的扫描透射电子显微镜，我们发现AFSWCNTs对革兰氏阳性菌具有更好的抗菌活性不仅归因于直接的物理接触和穿刺作用，还归因于与细菌表面官能团的分子尺度相互作用。AFSWCNTs的这种新型抗菌机制可能为设计针对耐药细菌种类的新型抗菌材料带来一种有前景的策略。
