Antibacterial mechanism of silver nanoparticles: a dose-dependent promotion of cell apoptosis

doi:10.3969/j.issn.2095-4344.2015.38.019

Abstract

Abstract:

BACKGROUND: Silver nanoparticles (AgNPs) show strong antibacterial effect and are not easy to have drug resistance. But the antibacterial mechanisms of AgNPs have not been well developed.
OBJECTIVE: To explain the antibacterial mechanisms of AgNPs.
METHODS: We investigated the influence of Ti, TiO₂ and TiO₂ containing AgNPs on Escherichia coli and Staphylococcus aureus by bacterial inhibition ring test. Escherichia coli was cultured in LB liquid medium with 0, 5, 10 mg/L AgNPs. We measured the absorbance value of bacterial culture. DNA gel electrophoresis was used to study the effect of AgNPs on Escherichia coli DNA. Then we researched the character of apoptosis on Escherichia coli by Annexin V and PI staining, using flow cytometry.
RESULTS AND CONCLUSION: The inhibiting effect of Ti and TiO₂ on Escherichia coli and Staphylococcus aureus was not obvious. But the inhibition rings of TiO₂ containing AgNPs to bacteria appeared. The absorbance value of Escherichia coli culture was reduced when Escherichia coli was co-cultured with AgNPs. And this decrease tendency was in direct proportion with AgNPs concentration. AgNPs reduced the amount of DNA of Escherichia coli and this tendency was directly proportional with AgNPs concentration. The Escherichia coli apoptosis rate induced by AgNPs was increased and this tendency was positively correlated to the AgNPs concentration. These results indicate that AgNPs can induce bacterial apoptosis to influence the growth of bacteria.

中国组织工程研究杂志出版内容重点：生物材料；骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性；组织工程

Key words: Silver, Escherichia coli, Nanoparticles

CLC Number:

R318

Yu Xiao-xu, Bao Hui-jing, Xu Chen, Li Xue, Li Zhao-yang, Zhang Yue-xiang, Liu Yun-de, Wei Dian-jun. Antibacterial mechanism of silver nanoparticles: a dose-dependent promotion of cell apoptosis[J]. Chinese Journal of Tissue Engineering Research, 2015, 19(38): 6173-6178.

Figures/Tables 3

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