CSIR - Institute of Genomics and Integrative Biology , Mathura Road , New Delhi 110025 , India.
Academy of Scientific and Innovative Research (AcSIR) , Anusandhan Bhawan, 2 Rafi Marg , New Delhi 110001 , India.
ACS Appl Mater Interfaces. 2018 May 9;10(18):15401-15411. doi: 10.1021/acsami.8b01463. Epub 2018 Apr 27.
Zinc oxide (ZnO) nanoparticles have been shown in the literature to have antibacterial properties and have been widely used in antibacterial formulations. However, one of the problems with ZnO nanoparticles is their tendency to aggregate, thereby causing damage to normal cells and lowering their antibacterial efficacy during application. In this work, we have attempted to avoid this by using a combination of ZnO nanoparticles and ionic liquids, a class of low melting salts containing organic cations and organic/inorganic anions that show antibacterial property as well, and tested the antibacterial activity of this dispersion. ZnO nanoparticles of 60 nm were dispersed in two different ionic liquids-choline acetate (IL1) and 1-butyl-3-methylimidazolium chloride (IL2)-to achieve high dispersibility, whereas ZnO dispersed in phosphate-buffered saline was taken as a control. These dispersions were tested on four strains- Escherichia coli, Bacillus subtilis, Klebsiella pneumoniae, and Staphylococcus epidermidis. Maximum efficiency was obtained for ZnO nanoparticles dispersed in imidazolium-based ionic liquids against skin-specific S. epidermidis. Skin infections induced by S. epidermidis are prevalent in hospital-acquired diseases. In most cases, traditional antibiotic-based therapies fail to combat such infections. Our strategy of developing a dispersion of ZnO nanoparticles in ionic liquids shows superior antibacterial efficacy in comparison to that shown individually by ZnO nanoparticles or ionic liquids. We have also established that the mechanism of killing this skin-specific bacterium is possibly through the production of reactive oxygen species leading to bacterial cell lysis. Further, we showed that this formulation is biocompatible and nontoxic to normal keratinocyte cells even under coculture conditions.
氧化锌（ZnO）纳米粒子在文献中已被证明具有抗菌性能，并已广泛应用于抗菌制剂中。然而，ZnO 纳米粒子的一个问题是它们容易聚集，从而在应用过程中对正常细胞造成损伤并降低其抗菌效果。在这项工作中，我们试图通过使用 ZnO 纳米粒子和离子液体的组合来避免这个问题，离子液体是一类低熔点盐，含有具有抗菌性能的有机阳离子和有机/无机阴离子，并测试了这种分散体的抗菌活性。将 60nm 的 ZnO 纳米粒子分散在两种不同的离子液体——醋酸胆碱（IL1）和 1-丁基-3-甲基咪唑氯化物（IL2）中，以实现高分散性，而分散在磷酸盐缓冲盐水中的 ZnO 则作为对照。将这些分散体在四种菌株——大肠杆菌、枯草芽孢杆菌、肺炎克雷伯菌和表皮葡萄球菌上进行了测试。在针对皮肤特有的表皮葡萄球菌的测试中，基于咪唑的离子液体中分散的 ZnO 纳米粒子的效率最高。由表皮葡萄球菌引起的皮肤感染在医院获得性疾病中很常见。在大多数情况下，传统的基于抗生素的治疗方法无法对抗此类感染。与 ZnO 纳米粒子或离子液体单独使用相比，我们开发的 ZnO 纳米粒子在离子液体中的分散体显示出优越的抗菌功效。我们还确定了这种杀死这种皮肤特有的细菌的机制可能是通过产生活性氧物质导致细菌细胞裂解。此外，我们表明，即使在共培养条件下，这种配方对正常角质形成细胞也是生物相容且无毒的。
