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

作者：Avinash Sonawnae, Jena, Soumitra Mohanty, Mallick, Jacob · 发表于：International Journal of Nanomedicine · 年份：2012 · DOI：10.2147/ijn.s28077 · 被引用次数：220 · 研究领域：Nanoparticles: synthesis and applications、Nanocomposite Films for Food Packaging、Antimicrobial agents and applications

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 th...