FDA National Center for Toxicological Research NCTR Publications > NCTR Research Highlights
Current Highlight from April 1, 2016 http://www.fda.gov/AboutFDA/CentersOffices/OC/OfficeofScientificandMedicalPrograms/NCTR/WhatWeDo/NCTRPublications/ucm076767.htm Size- and Dose-Dependent Antiviral Effects of Silver Nanoparticles NCTR scientists have demonstrated both size- and dose-dependent antiviral effects of silver nanoparticles (AgNPs) in in vitro assays using feline calicivirus (FCV) as a surrogate for human norovirus. Treatment of cultures with 10 nanometer (nm)-sized AgNPs (at doses of 50 and 100 micrograms per milliliter [µg/mL]) completely inactivated FCV within 2-4 hours of exposure, resulting in a decrease in the viral titer, an absence of cytopathic effects in Crandell-Rees Feline Kidney cells, and a reduction in viral capsid protein levels; whereas no effect was observed with 75 and 110 nm-sized AgNPs. The use of AgNPs as antibacterial agents has increased in consumer-use products; however, its use as an antiviral agent is still an area of active research. This study is now available online at Foodborne Pathogens and Disease: http://dx.doi.org/10.1089/fpd.2015.2054 For additional information, please contact Sangeeta Khare, Ph.D., Division of Microbiology, FDA/NCTR. >>> Foodborne Pathogens and Disease - March 2016, ahead of print. Dose and Size-Dependent Antiviral Effects of Silver Nanoparticles on Feline Calicivirus, a Human Norovirus Surrogate Aschalew Z. Bekele, Kuppan Gokulan, Katherine M. Williams, and Sangeeta Khare ABSTRACT Objectives: Silver nanoparticles (AgNPs) as antibacterial agents are incorporated in many consumer products, while the use as antiviral agents is an ongoing area of research. We evaluated the antiviral properties of AgNPs of variable sizes (10, 75, and 110 nm) and doses (25, 50, and 100 µg/mL) at different contact time points against feline calicivirus (FCV), a surrogate for norovirus. Materials and Methods: Antiviral effects of the AgNPs were determined by comparing the infectivity of FCV, the appearance of cytopathic effects (CPEs), and the integrity of the viral capsid protein in viral suspension treated with AgNPs with the untreated controls. Results: The 10 nm AgNPs at 50 and 100 µg/mL concentrations inactivated the FCV beyond the limit of detection, resulting in a decrease of up to 6.5 log10 viral titer, prevented development of CPEs, and reduction in the western blot band signal of the viral capsid protein. No significant antiviral effect was observed for the 75 and 110 nm AgNPs. Conclusions and Applications: These results demonstrate that the antiviral effects of AgNPs are both size and dose dependent, thus potential applications of AgNPs as antiviral agents to prevent contamination of foodborne viruses need to consider size and dose effects. Copyright©2012 Mary Ann Liebert, Inc. publishers. All rights reserved, USA and worldwide. http://dx.doi.org/10.1089/fpd.2015.2054 >>> http://sci-hub.io/ Download the PDF: "Dose and Size-Dependent Antiviral Effects of Silver Nanoparticles on Feline Calicivirus" http://moscow.sci-hub.io/89110c87b9fd1021ebae66d5b3d4f000/bekele2016.pdf ( Link may expire - if so, reenter the search. ) Bill .. -- The Silver List is a moderated forum for discussing Colloidal Silver. Rules and Instructions: http://www.silverlist.org Unsubscribe: <mailto:[email protected]?subject=unsubscribe> Archives: http://www.mail-archive.com/[email protected]/maillist.html Off-Topic discussions: <mailto:[email protected]> List Owner: Mike Devour <mailto:[email protected]>
