کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5861049 | 1562710 | 2016 | 14 صفحه PDF | دانلود رایگان |
- Toxicity of AgNPs to Saccharomyces cerevisiae wild-type (wt) and its 9 isogenic mutants was compared.
- AgNPs were internalized by end3p-mediated endocytosis.
- Endocytosis mutant end3Î was more sensitive than wt to AgNPs, Ag-ions, SDS and H2O2.
- Toxicity of AgNPs and Ag-ions was not caused by the ROS or cell's membrane permeabilization.
The widespread use of nanosilver in various antibacterial, antifungal, and antiviral products warrants the studies of the toxicity pathways of nanosilver-enabled materials toward microbes and viruses. We profiled the toxicity mechanisms of uncoated, casein-coated, and polyvinylpyrrolidone-coated silver nanoparticles (AgNPs) using Saccharomyces cerevisiae wild-type (wt) and its 9 single-gene deletion mutants defective in oxidative stress (OS) defense, cell wall/membrane integrity, and endocytosis. The 48-h growth inhibition assay in organic-rich growth medium and 24-h cell viability assay in deionized (DI) water were applied whereas AgNO3, H2O2, and SDS served as positive controls. Both coated AgNPs (primary size 8-12Â nm) were significantly more toxic than the uncoated (~Â 85Â nm) AgNPs. All studied AgNPs were ~Â 30 times more toxic if exposed to yeast cells in DI water than in the rich growth medium: the IC50 based on nominal concentration of AgNPs in the growth inhibition test ranged from 77 to 576Â mg Ag/L and in the cell viability test from 2.7 to 18.7Â mg Ag/L, respectively. Confocal microscopy showed that wt but not endocytosis mutant (end3Î) internalized AgNPs. Comparison of toxicity patterns of wt and mutant strains defective in OS defense and membrane integrity revealed that the toxicity of the studied AgNPs to S. cerevisiae was not caused by the OS or cell wall/membrane permeabilization.
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Journal: Toxicology in Vitro - Volume 35, September 2016, Pages 149-162