Lab of Inorganic Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
Department of Physics, Aristotle University of Thessaloniki, Thessaloniki, Greece.
J Inorg Biochem. 2017 Dec;177:159-170. doi: 10.1016/j.jinorgbio.2017.09.014. Epub 2017 Sep 23.
There is a growing field of research on the physicochemical properties of bimetallic nanoparticles (BMNPs) and their potential use in different applications. Meanwhile, their antimicrobial activity is scarcely reported, although BMNPs can potentially achieve unique chemical transformations and synergetic effects can be presented. Towards this direction a reproducible simple hybrid polyol process under moderate temperature solvothermal conditions has been applied for the isolation of non-oxide contaminated bimetallic CuFe nanoparticles (NPs). 1,2-propylene glycol (PG), tetraethylene glycol (TEG) and polyethylene glycol (PEG 8000), that exhibit different physicochemical properties, have been utilized to regulate the size, structure, composition and the surface chemistry of NPs. The BMNPs were found to be of small crystalline size, 30-45nm, and high hydrophilicity, different wt% percentage of organic coating and variable hydrodynamic size and surface charge. The antimicrobial activity of the BMNPs was evaluated against the bacterial strains B. subtilis, E. coli and fungus S. cerevisiae. The IC values for CuFe NPs were found significantly lower compared with Cu NPs of the same size, revealing an enhancement in the antimicrobial activity when iron and copper coexist in the crystal structure. The reactive oxygen species (ROS) production was measured intracellularly and extracellularly by the nitroblue tetrazolium assay in the fungal cultures. No extracellular ROS were measured suggesting that both CuFe and Cu NPs enter the fungal cells during the incubation, also verified by optical imaging of the fungal cells in the presence of NPs. Higher ROS concentrations were generated intracellularly for CuFe NPs supporting different red/ox reaction mechanisms.
目前，关于双金属纳米粒子（BMNPs）的物理化学性质及其在不同应用中的潜在用途的研究领域正在不断扩大。然而，尽管 BMNPs 可能实现独特的化学转化，并且可能呈现协同效应，但它们的抗菌活性却鲜有报道。针对这一方向，我们采用可重复的简单杂化多元醇工艺，在中等温度溶剂热条件下，成功分离出了无氧化物污染的双金属 CuFe 纳米粒子（NPs）。1,2-丙二醇（PG）、四乙二醇（TEG）和聚乙二醇（PEG 8000）具有不同的物理化学性质，可用于调节 NPs 的尺寸、结构、组成和表面化学性质。结果表明，BMNPs 的结晶尺寸小，为 30-45nm，具有高亲水性，不同 wt%的有机涂层比例，以及可变的水动力尺寸和表面电荷。我们评估了 BMNPs 对枯草芽孢杆菌、大肠杆菌和真菌酿酒酵母等细菌菌株的抗菌活性。结果发现，CuFe NPs 的 IC 值明显低于相同尺寸的 Cu NPs，这表明当铁和铜共存于晶体结构中时，抗菌活性得到了增强。通过真菌培养物中的硝基四氮唑蓝测定法，在细胞内和细胞外测量了活性氧（ROS）的产生。未测量到细胞外 ROS，这表明 CuFe 和 Cu NPs 在孵育过程中均进入了真菌细胞，这也通过存在 NPs 时真菌细胞的光学成像得到了验证。细胞内产生了更高浓度的 ROS，支持不同的氧化还原反应机制。
