New toxicity mechanism of silver nanoparticles: promoting apoptosis and inhibiting proliferation

PLoS One. 2015 Mar 30;10(3):e0122535. doi: 10.1371/journal.pone.0122535. eCollection 2015.


Silver nanoparticles are increasingly recognized for their utility in biological applications, especially antibacterial effects. Herein, we confirmed the antibacterial effect of silver nanoparticles on Escherichia coli using the conventional optical density (OD) and colony-forming units (CFU) method and used flow cytometry (FC), TEM and BrdU ELISA to investigate the mechanisms of this effect. From the results, we conclude that AgNPs can simultaneously induce apoptosis and inhibit new DNA synthesis in the cells in a positive concentration-dependent manner. This study presents the first induction of apoptosis in these bacteria by AgNPs in this field. Our findings may provide a new strategy for the use of silver nanoparticles in antibacterial applications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / chemistry*
  • Anti-Bacterial Agents / pharmacology*
  • Apoptosis / drug effects*
  • Cell Proliferation / drug effects
  • DNA, Bacterial / biosynthesis
  • Dose-Response Relationship, Drug
  • Escherichia coli / cytology
  • Escherichia coli / drug effects
  • Escherichia coli / growth & development
  • Escherichia coli / metabolism
  • Metal Nanoparticles*
  • Silver / chemistry*
  • Silver / pharmacology*


  • Anti-Bacterial Agents
  • DNA, Bacterial
  • Silver

Grant support

This work was supported by the key discipline of Tianjin medical funding (201301), Tianjin medical university funding (2011KY42). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.