title: Dose and Size-Dependent Antiviral Effects of Silver Nanoparticles on Feline Calicivirus, a Human Norovirus Surrogate.
abstract: 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.
  
  
  
  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.
  
  
  
  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.
authors.affiliation: Division of Microbiology, National Center for Toxicological Research , U.S. Food and Drug Administration, Jefferson, Arkansas.
authors.forename: Aschalew Z
authors.initials: AZ
authors.lastname: Bekele
authors.affiliation: Division of Microbiology, National Center for Toxicological Research , U.S. Food and Drug Administration, Jefferson, Arkansas.
authors.forename: Kuppan
authors.initials: K
authors.lastname: Gokulan
authors.affiliation: Division of Microbiology, National Center for Toxicological Research , U.S. Food and Drug Administration, Jefferson, Arkansas.
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Williams
authors.affiliation: Division of Microbiology, National Center for Toxicological Research , U.S. Food and Drug Administration, Jefferson, Arkansas.
authors.forename: Sangeeta
authors.initials: S
authors.lastname: Khare
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D017250:Caliciviridae Infections / Q000188:drug therapy / Q000662:veterinary*; D017927:Calicivirus, Feline / Q000187:drug effects*; D002371:Cat Diseases / Q000188:drug therapy* / Q000821:virology; D002415:Cats; D004305:Dose-Response Relationship, Drug; D004339:Drug Compounding; D053758:Nanoparticles; D012834:Silver / Q000494:pharmacology*
chemical_list: D000998:Antiviral Agents; D012834:Silver