Tungsten carbide nanoparticles show a broad spectrum virucidal activity against enveloped and nonenveloped model viruses using a guideline‐standardized in vitro test

Abstract

Five tungsten carbide nanoparticle preparations (denoted WC1‐WC5) were investigated for broad spectrum virucidal activity against four recommended model viruses. These are modified vaccinia virus Ankara (MVA), human adenovirus type 5 (HAdV‐5), poliovirus type 1 (PV‐1) and murine norovirus (MNV). All virucidal tests were performed two to five times using the quantitative suspension test, which is a highly standardized test method to evaluate the virucidal efficacy of disinfectants in accordance with the European norm EN 14476+A1 and the German DVV/RKI guidelines. Quantitative detection of viruses was conducted by endpoint titration and quantitative real‐time PCR. Results showed that three of the five tested compounds (WC1‐WC3) were able to reduce the infectivity of all model viruses by at least four log10 of tissue culture infective dose 50% per ml after 15 min, whereas the other two compounds exhibited only limited efficacy (WC4) or showed cytotoxicity (WC5). Virucidal activity of nanoparticles increased with incubation time and a dose‐effect curve showed dependence of virucidal activity with particle concentration. Whereas WC1‐WC4 showed little cytotoxicity, WC5 which was doped with copper exhibited a significant cytotoxic effect. These findings propose tungsten carbide nanoparticles to be very promising in terms of new disinfection techniques. Significance and Impact of the Study The present study investigates the virucidal activity of tungsten carbide nanoparticles using the quantitative suspension test in accordance with the European norm EN 14476+A1 and the German DVV/RKI guidelines. Due to highly standardized assay conditions, results of this test are considered very reliable for evaluation of the virucidal activity of disinfectants. Broad‐spectrum activity and high efficacy of three different tungsten carbide nanoparticles preparations is concluded.

Metal Nanoparticles: a Promising Treatment for Viral and Arboviral Infections

“…Therefore, the NPs could easily interact with the viral particles to inhibit viral binding to the host cells and replication. Pfaff et al [49] also reported that exposure to tungsten carbide NPs caused a 3.5-log reduction in poliovirus infectivity within 15 min. However, it is unfortunate that research on the use of metal NPs for poliovirus treatment is scanty and warrants further investigation.…”

“…Both types of NPs showed to be effective against adenovirus with 96% and 100% inhibition. Pfaff et al [49] showed that tungsten carbide NPs could reduce the infectivity of adenovirus type 5 by 50% in 15 min. These NPs also displayed significant antiviral activity against other types of viruses such as modified vaccina virus Ankara (MVA), poliovirus, and norovirus.…”

“…These NPs also displayed significant antiviral activity against other types of viruses such as modified vaccina virus Ankara (MVA), poliovirus, and norovirus. In this regard, these NPs might be utilized as an effective nanotechnology-based disinfectant [49]. μg/mL for 12 h reduced plaque formation unit (PFU) from 3.8 × 10 5 to 2.5 × 10 2 per mL.…”

“…Agnihothram et al [155] showed that anatase titanium dioxide NPs (20 μg/mL) reduced cell viability of murine norovirus (MNV)-infected RAW 264.7 macrophages by 50% and 75%, at 24 h and 48 h post-infection respectively. Pfaff et al [49] reported that exposure to tungsten carbide NPs caused a four-log reduction of MNV within 15 min. Ultimately, their findings also suggested that tungsten carbide NPs may be a promising antiviral agent against norovirus, other non-enveloped, and enveloped viruses [49].…”

“…Pfaff et al [49] reported that exposure to tungsten carbide NPs caused a four-log reduction of MNV within 15 min. Ultimately, their findings also suggested that tungsten carbide NPs may be a promising antiviral agent against norovirus, other non-enveloped, and enveloped viruses [49].…”