Back to Journals » International Journal of Nanomedicine » Volume 7

Toxicity and antibacterial assessment of chitosan-coated silver nanoparticles on human pathogens and macrophage cells

Authors Jena, Mohanty, Mallick, Jacob, Sonawnae A

Received 9 November 2011

Accepted for publication 11 December 2011

Published 3 April 2012 Volume 2012:7 Pages 1805—1818


Review by Single anonymous peer review

Peer reviewer comments 2

Prajna Jena1, Soumitra Mohanty1, Rojee Mallick1, Biju Jacob2, Avinash Sonawane1
1School of Biotechnology, KIIT University, Bhubaneswar, Orissa, India; 2Center for Innovation, Technopark Technology Business Incubator, Bangalore, Karnataka, India

Background: Pathogenic bacteria are able to develop various strategies to counteract the bactericidal action of antibiotics. Silver nanoparticles (AgNPs) have emerged as a potential alternative to conventional antibiotics because of their potent antimicrobial properties. The purpose of this study was to synthesize chitosan-stabilized AgNPs (CS-AgNPs) and test for their cytotoxic, genotoxic, macrophage cell uptake, antibacterial, and antibiofilm activities.
Methods: AgNPs were synthesized using chitosan as both a stabilizing and a reducing agent. Antibacterial activity was determined by colony-forming unit assay and scanning electron microscopy. Genotoxic and cytotoxic activity were determined by DNA fragmentation, comet, and MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assays. Cellular uptake and intracellular antibacterial activity were tested on macrophages.
Results: CS-AgNPs exhibited potent antibacterial activity against different human pathogens and also impeded bacterial biofilm formation. Scanning electron microscopy analysis indicated that CS-AgNPs kill bacteria by disrupting the cell membrane. CS-AgNPs showed no significant cytotoxic or DNA damage effect on macrophages at the bactericidal dose. Propidium iodide staining indicated active endocytosis of CS-AgNPs resulting in reduced intracellular bacterial survival in macrophages.
Conclusion: The present study concludes that at a specific dose, chitosan-based AgNPs kill bacteria without harming the host cells, thus representing a potential template for the design of antibacterial agents to decrease bacterial colonization and to overcome the problem of drug resistance.

Keywords: chitosan-silver nanoparticles, antibiofilm, cytotoxicity, genotoxicity

A Letter to the Editor has been received and published for this article.

Creative Commons License This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.

Download Article [PDF]  View Full Text [HTML][Machine readable]