Synergetic effect of silver nanoparticles and thiram on lipid bilayers

Abstract

The excessive concentration of nanomaterials and pesticides in industrial products, food, and in the environment can be a risk to human health. Exposure to these materials can occur through inhalation, dermal contact, or oral ingestion, which depends directly on the type of products we are exposed to. Extensive studies about the individual action of these compounds have been described. However, the effect of these mixtures (nanoparticles and pesticides, for instance) requires more investigation. Here, we evaluated by phase-contrast microscopy the individual and mixture effects of silver nanoparticles (AgNp) and thiram pesticide on mimetic systems of the lipid bilayer structure of the plasma membrane using DOPC (1,2-dioleoyl-sn-glycero-3-phosphocholine) giant unilamellar vesicles (GUVs). Besides, the effect of thiram pesticide on DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine) multilamellar vesicles containing AgNp (encapsulated) was also evaluated by surface-enhanced Raman scattering (SERS). The results showed a synergetic effect of the AgNp and thiram mixture, which lead to a loss of phase contrast intensity and rupture of the lipid bilayers. The synergetic effect was ascribed to the strong interaction AgNp-thiram through Ag-S bond formation.