Cytotoxicity and biointeractions of nanosilver in macrophages

A. Pratsinis, P. Hervella, J.-C. Leroux, S.E. Pratsinis, G.A. Sotiriou
ETH Zurich, CH

Keywords: Ag nanoparticles, Ag+ ion, dissolution, RAW 264.7, hyperspectral imaging


Silver nanoparticles (nanosilver) are broadly used today in textiles, food packaging, household devices and bioapplications, prompting a better understanding of their toxicity and biological interactions. Here, nanosilver of well-defined size (5.7 to 20.4 nm) supported on inert nanostructured silica was produced using flame aerosol technology. The cytotoxicity of the prepared nanosilver with respect to murine macrophages was assessed in vitro because these cells are among the first to confront nanosilver upon its intake by mammals. The size of the nanosilver dictated its mode of cytotoxicity (Ag+ ion-specific and/or particle-specific). The toxicity of small nanosilver (< 10 nm) was mostly mediated by the released Ag+ ions. The influence of such ions on the toxicity of nanosilver decreased with increasing nanosilver size (> 10 nm). Direct silver nanoparticle-macrophage interactions dominated the nanosilver toxicity at sizes larger than 10 nm.