Particle-cell contact enhances antibacterial activity of silver nanoparticles.
Particle-cell contact enhances antibacterial activity of silver nanoparticles.
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DOI：
10.1371/journal.pone.0064060
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Kahru A
中科院分区：
文献类型：
--
作者：
Bondarenko O;Ivask A;Käkinen A;Kurvet I;Kahru A
银纳米粒子的抗菌性能与其溶解度有关。然而，仅基于溶解的概念不能完全解释纳米颗粒银与银离子相比的毒性效力。在此，我们证明了细菌细胞与AgNPs表面之间的直接接触增强了纳米银的毒性。更具体地说，细胞-NP接触增加了颗粒相关的Ag离子的细胞摄取-毒性的单一和最终原因。为了证明这一点，我们评估了三种不同的AgNP（未涂覆的、PVP涂覆的和蛋白质涂覆的）对六种细菌菌株的毒性：革兰氏阴性大肠杆菌、荧光假单胞菌、恶臭假单胞菌和铜绿假单胞菌以及革兰氏阳性枯草芽孢杆菌和金黄色葡萄球菌。虽然AgNO 3对这些细菌的毒性仅略有不同（4小时EC 50范围为0.3至1.2 mg Ag/l），但蛋白质包被的AgNPs对各种细菌菌株的4小时EC 50值差异显着，从0.35至46 mg Ag/l。通过系统地比较细胞内和细胞外游离Ag+从AgNPs中释放，我们证明，不仅在细菌测试环境中的细胞外溶解，而且在颗粒-细胞界面处发生的额外溶解在AgNPs的抗菌作用中起着至关重要的作用。NP-细胞接触在决定Ag-NP的抗菌活性中的作用另外通过以下观察得到证明：（i）通过颗粒不可渗透的膜（截止20 kDa，约4 nm）将细菌细胞与AgNP分离显著降低了AgNP的毒性，和（ii）倾向于附着在AgNP上的铜绿假单胞菌细胞对所有形式的纳米颗粒Ag表现出最高的敏感性。我们的研究结果为纳米银的抗菌作用模式提供了新的见解，并解释了这一领域的一些差异，表明“银离子”和“颗粒特异性”机制没有争议，而是同一枚硬币的两个面。
It is generally accepted that antibacterial properties of Ag nanoparticles (AgNPs) are dictated by their dissolved fraction. However, dissolution-based concept alone does not fully explain the toxic potency of nanoparticulate silver compared to silver ions. Herein, we demonstrated that the direct contact between bacterial cell and AgNPs' surface enhanced the toxicity of nanosilver. More specifically, cell-NP contact increased the cellular uptake of particle-associated Ag ions – the single and ultimate cause of toxicity. To prove that, we evaluated the toxicity of three different AgNPs (uncoated, PVP-coated and protein-coated) to six bacterial strains: Gram-negative Escherichia coli, Pseudomonas fluorescens, P. putida and P. aeruginosa and Gram-positive Bacillus subtilis and Staphylococcus aureus. While the toxicity of AgNO3 to these bacteria varied only slightly (the 4-h EC50 ranged from 0.3 to 1.2 mg Ag/l), the 4-h EC50 values of protein-coated AgNPs for various bacterial strains differed remarkably, from 0.35 to 46 mg Ag/l. By systematically comparing the intracellular and extracellular free Ag+ liberated from AgNPs, we demonstrated that not only extracellular dissolution in the bacterial test environment but also additional dissolution taking place at the particle-cell interface played an essential role in antibacterial action of AgNPs. The role of the NP-cell contact in dictating the antibacterial activity of Ag-NPs was additionally proven by the following observations: (i) separation of bacterial cells from AgNPs by particle-impermeable membrane (cut-off 20 kDa, ∼4 nm) significantly reduced the toxicity of AgNPs and (ii) P. aeruginosa cells which tended to attach onto AgNPs, exhibited the highest sensitivity to all forms of nanoparticulate Ag. Our findings provide new insights into the mode of antibacterial action of nanosilver and explain some discrepancies in this field, showing that “Ag-ion” and “particle-specific” mechanisms are not controversial but, rather, are two faces of the same coin.
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影响因子：
2.8
作者：
BRAGG, PD;RAINNIE, DJ
通讯作者：
RAINNIE, DJ
影响因子：
1.1
作者：
Dror-Ehre, Avital;Adin, Avner;Mamane, Hadas
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5
作者：
Li, Wen-Ru;Xie, Xiao-Bao;Chen, Yi-Ben
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17.1
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George S;Lin S;Ji Z;Thomas CR;Li L;Mecklenburg M;Meng H;Wang X;Zhang H;Xia T;Hohman JN;Lin S;Zink JI;Weiss PS;Nel AE
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Nel AE
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