The mechanism of antibacterial action of silver nanoparticles (AgNp) was investigated by employing a combination of microbiology and geochemical approaches to contribute to the realistic assessment of nanotoxicity. Our studies showed that suspending AgNp in media with different levels of chloride relevant to environmental conditions produced low levels of ionic silver thereby suggesting that dissolution of silver ions from nanoparticulate surface could not be the sole mechanism of toxicity. An Escherichia coli based bioreporter strain responsive to silver ions together with mutant strains of E. coli lacking specific protective systems were tested against AgNp. Deletion mutants lacking silver ion efflux systems and resistance mechanisms against oxidative stress showed an increased sensitivity to AgNp. However, the bioreporter did not respond to silver nanoparticles. Our results suggest that oxidative stress is a major toxicity mechanism and that this is at least partially associated with ionic silver, but that bulk dissolution of silver into the medium is not sufficient to account for the observed effects. Chloride ions do not appear to offer significant protection, indicating that chloride in receiving waters will not necessarily protect environmental bacteria from the toxic effects of nanoparticles in effluents.
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http://dx.doi.org/10.1016/j.jhazmat.2014.12.066 | DOI Listing |
Int J Biol Macromol
January 2025
School of Chemical Engineering, Changchun University of Technology, Changchun 130012, China.
In this study, the dispersion behavior of MoS₂ in ionic liquids (ILs) with varying alkyl chain lengths was the primary focus of investigation, followed by the design of a novel PAM/SMA/CMC/PDA@MoS hydrogel. By optimizing the concentrations of CMC and PDA@MoS, a bifunctional hydrogel with both sensing and catalytic functions was successfully developed. Mechanical tests revealed that the PAM/SMA/CMC/0.
View Article and Find Full Text PDFJ Chromatogr A
January 2025
Office of Pharmaceutical Quality Research, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, U.S. Food and Drug Administration, Silver Spring, Maryland 20993, USA. Electronic address:
Asymmetrical flow field-flow fractionation (AF4) with multi-detection has continued to gain wider acceptance for characterizing complex drug products. An important quality attribute for these products is the measurement of the particle size distribution (PSD). Current limitations of established procedures (e.
View Article and Find Full Text PDFAntibiotics (Basel)
December 2024
Faculty of Natural Science, Pavol Jozef Safarik University in Kosice, Srobarova 2, 041 54 Kosice, Slovakia.
Introduction: Silver nanoparticles (AgNPs) are widely utilized for their exceptional antimicrobial properties, but concerns persist regarding their environmental impacts, particularly in soil and water ecosystems. This study compared the effects of chemically and biologically synthesized AgNPs and ionic silver on bacterial communities commonly present in soil and the proliferation of antibiotic resistance in the soil ecosystem.
Results And Discussion: Biologically synthesized AgNPs exhibited the strongest antimicrobial activity, significantly reducing bacterial populations within a day, and demonstrated minimal impacts on the development of antibiotic resistance in long-term.
Sci Rep
January 2025
Faculty of Marine Engineering, Gdynia Maritime University, Morska 81-87, 81-225, Gdynia, Poland.
This paper presents the effect of environmentally friendly additives on selected parameters and microbial degradation of Marine Diesel Oil (MDO). Microbiological contamination is a serious problem in MDO and other petroleum products. For this reason, it was decided to investigate the effects of environmentally friendly additives such as silver solution and colloidal nanosilver, as well as effective liquid microorganisms and ceramic tubes with different percentages of them in diesel oil (MDO) on its selected parameters and inhibition of bacterial and fungal growth.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
January 2025
Department of Chemistry, Veer Surendra Sai University of Technology, Burla, Sambalpur 768018 Odisha, India. Electronic address:
Sensing of amino acid serves as the frontier research area for early diagnosis and monitoring various diseases. Among various amino acids, the sensing of L-Cysteine is much important for detection of human diseases like neurotoxic effect and coronary heart disease which arises due to excess of L-Cysteine. To address this, we propose a very simple method of L-Cys sensing via fluorescence "TURN ON" mechanism involving silver centred Rhodamine B nanogranules (AgNPs/RhB) stabilized via electrostatic interaction.
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