Mechanism of antibacterial activity of copper nanoparticles
Mechanism of antibacterial activity of copper nanoparticles
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DOI：
10.1088/0957-4484/25/13/135101
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发表时间：
2014-04-04
期刊：
影响因子：
3.5
通讯作者：
Basu, Tarakdas
中科院分区：
文献类型：
--
作者：
Chatterjee, Arijit Kumar;Chakraborty, Ruchira;Basu, Tarakdas
在之前的通讯中，我们报道了一种合成稳定金属铜纳米颗粒（Cu-NPs）的新方法，该方法具有高效的细菌细胞丝化和细胞杀伤作用。本文研究了Cu-NPs在大肠杆菌细胞中的丝形成机制和抗菌作用。我们的研究结果表明，np介导的细胞膜电位耗散可能是细胞细丝形成的原因。另一方面，Cu-NPs在大肠杆菌细胞中引起多种毒性作用，如活性氧的产生、脂质过氧化、蛋白质氧化和DNA降解。质粒pUC19 DNA与Cu-NPs的体外相互作用表明，在二价金属离子螯合剂EDTA的存在下，DNA的降解受到高度抑制，这表明Cu2+离子在降解过程中发挥了积极作用。此外，NPs在EDTA存在下的快速失稳（即尺寸减小）使我们提出，从NP表面释放的新生Cu离子比等量的前体CuCl2具有更高的反应活性；新生离子是金属NPs在细胞、生物分子或介质组分附近氧化而产生的，同时被还原。
In a previous communication, we reported a new method of synthesis of stable metallic copper nanoparticles (Cu-NPs), which had high potency for bacterial cell filamentation and cell killing. The present study deals with the mechanism of filament formation and antibacterial roles of Cu-NPs in E. coli cells. Our results demonstrate that NP-mediated dissipation of cell membrane potential was the probable reason for the formation of cell filaments. On the other hand, Cu-NPs were found to cause multiple toxic effects such as generation of reactive oxygen species, lipid peroxidation, protein oxidation and DNA degradation in E. coli cells. In vitro interaction between plasmid pUC19 DNA and Cu-NPs showed that the degradation of DNA was highly inhibited in the presence of the divalent metal ion chelator EDTA, which indicated a positive role of Cu2+ ions in the degradation process. Moreover, the fast destabilization, i.e. the reduction in size, of NPs in the presence of EDTA led us to propose that the nascent Cu ions liberated from the NP surface were responsible for higher reactivity of the Cu-NPs than the equivalent amount of its precursor CuCl2; the nascent ions were generated from the oxidation of metallic NPs when they were in the vicinity of agents, namely cells, biomolecules or medium components, to be reduced simultaneously.