Antimicrobial activity and the mechanism of silver nanoparticle thermosensitive gel

Abstract

Purpose

The purpose of the present study was to elucidate the antimicrobial activity and mechanism of silver nanoparticles incorporated into thermosensitive gel (S-T-Gel) on Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa.

Patients and methods

This study investigated the growth, permeability, and morphology of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa cells in order to observe the action of S-T-Gel on the membrane structure of these three bacteria. The cell morphology of normal and treated bacteria cells was assessed by transmission electron microscopy (TEM), and the effects of S-T-Gel on genome DNA of bacterial cells were evaluated by agarose gel electrophoresis.

Results

S-T-Gel showed promising activity against Staphylococcus aureus and moderate activity against Escherichia coli and Pseudomonas aeruginosa. The observation with TEM suggested that S-T-Gel may destroy the structure of bacterial cell membranes in order to enter the bacterial cell. S-T-Gel then condensed DNA and combined and coagulated with the cytoplasm of the damaged bacteria, resulting in the leakage of the cytoplasmic component and the eventual death of these three bacteria. In addition, the analysis of agarose gel electrophoresis demonstrated that S-T-Gel could increase the decomposability of genome DNA.

Conclusion

These results about promising antimicrobial activity and mechanism of S-T-Gel may be useful for further research and development in in-vivo studies.

Keywords:

• molecule mechanism
• bacterial cells
• S-T-Gel

Acknowledgments

The work was supported by National Science and Technology Foundation of China “The Creation for Significant New Drugs” (2009ZX09501-023), the Science and Technology Planning Project of Guangdong Province, China (Project No. 2007B03070400), and the University of Macau research fund (UL016A/09-Y2/CMS/WYT01/ICMS).

Disclosure

The authors declare that they have no competing interests.