Virucidal properties of metal oxide nanoparticles and their halogen adducts

Abstract

Selected metal oxide nanoparticles are capable of strongly adsorbing large amounts of halogens (Cl(2), Br, I(2)) and mixed halogens. These solid adducts are relatively stable thermally, and they can be stored for long periods. However, in the open environment, they are potent biocides. Herein are described studies with a number of bacteriophage MS2, phiX174, and PRD-1 (virus examples). PRD-1 is generally more resistant to chemical disinfection, but in this paper it is shown to be very susceptible to selected interhalogen and iodine adducts of CeO(2), Al(2)O(3), and TiO(2) nanoparticles. Overall, the halogen adducts of TiO(2) and Al(2)O(3) were most effective. The mechanism of disinfection by these nanoparticles is not completely clear, but could include abrasive properties, as well as oxidative powers. A hypothesis that nanoparticles damage virons or stick to them and prevent binding to the host cell is a consideration that needs to be explored. Herein are reported comparative biocidal activities of a series of adducts and electron microscope images of before and after treatment.

Perturbation of an arctic soil microbial community by metal nanoparticles

“…3). Perhaps this is not surprising considering that this order is characterized by known spore-formers, which survive under extreme conditions, and is also consistent with previous observations showing that several metal oxide NPs had little impact on spores in culture [34]. However, with that one exception, every major order, together, showed an overall 44% decrease in the relative number of recovered sequences.…”

Influence of a nanoparticle mixture on an arctic soil community

“…Over time, more resilient organisms, possibly such as spore formers [38], could proliferate as a result of reduced competition from more susceptible species. Overall, then, the structure of the microbial community was perturbed.…”

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

“…Virucidal activity of WC5 was restricted to HAdV‐5 and MNV, whereas WC4 showed insufficient virucidal activity. Comparable results have been reported with several halogenated metal oxide nanoparticles, but their virucidal activity relied primarily on the halogen component rather than the nanoparticles themselves (Koper et al ; Haggstrom et al ).…”

“…Several studies reported on silver-based nanoparticles with virucidal effects (Galdiero et al 2011;Lara et al 2011), but it is noteworthy that these nanoparticles failed to achieve a reduction of infectivity by at least four log 10 of tissue culture infective dose 50% (TCID 50 ) per ml. Virucidal activity was also shown for other nanomaterials including metal oxides and their halogen adducts (Koper et al 2002;Haggstrom et al 2010) as well as gold-and copperbased nanoparticles (Papp et al 2010;Broglie et al 2015;Rafiei et al 2016). In most cases, own test regimes were developed and virucidal tests did not follow standardized guidelines, for example, the European norm EN 14476+A1 (CEN 2015) or the German DVV/RKI guideline (Rabenau et al 2015).…”