Evaluation of the Toxicity of Silver/Silica and Titanium Dioxide Particles in Mammalian Cells

Abstract

The increasing concern over the spread of diseases has lead to a high consumption of antimicrobial additives in the medical and industrial fields. Since these particles can lixiviate from loaded materials, the contact between this additive and mammalian cells can occur during manufacture, use and disposal of the products. Silver on fumed silica (AgNP_SiO2) and titanium dioxide (TiO2) can be used as antimicrobial additives that are applied in polymeric formulation. While these additives can inhibit bacteria, fungus and virus proliferation; they may also be harmful to humans. Standard toxicological studies were undertaken using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide), CBPI (cytokinesis-block proliferation index) and micronucleus assay using different sets of additive concentrations. The nanosize of the samples evaluated was confirmed by transmission electronic microscopy. No significant micronucleus frequency increase or cell viability reduction were observed with the exposure of L-929 murine fibroblast cells to AgNP_SiO2 and TiO2 particles at any of the tested concentrations. The non toxic effect of the analyzed particles can be explained by considering its agglomeration tendency, composition, and crystalline form. Further investigations should be done to understand the interference of agglomeration and how it affects the toxicological study.

Behaviour of Titanium Dioxide Particles in Artificial Body Fluids and Human Blood Plasma

“…Of these, Pittol et al, for example, observed no significant reduction in viability after the exposure of mouse fibroblast cells (L929) to TiO 2 particles, even at the highest concentrations of 10,000 μg/g. The authors attributed the non-toxic effect of the particles to their agglomeration tendency, composition, and crystalline form, together with their interaction in culture media [ 61 ]. Similarly, Rosłon et al observed only a slight effect of TiO 2 NPs on the viability of mouse fibroblasts (L929)—however, at a notably lower range of tested concentrations (10–200 μg/mL) [ 62 ].…”

SiO2–TiO2 Nanoparticle Aqueous Foam for Volatile Organic Compounds’ Suppression

“…The hydrophobic property of nanosilica after surface modification is strongly related to its lipophilicity, and the degree of lipophilicity, which is related to methanol consumption, is a common index used to evaluate the abundance of hydrophobic functional groups on the surface of nanosilica. A higher lipophilic degree means more methanol consumption, reflecting a strong lipophilicity and outstanding hydrophobic performance [ 35 , 36 ]. According to the relative experimental method, 0.2 g of well-prepared hydrophobic nanosilica particles were added into a beaker containing 50 mL of deionized water.…”

“…In a bench-scale experiment, a SiO 2 core–TiO 2 shell composite nanoparticle was shown to enhance the photocatalysis of nano-TiO 2 [ 34 ]. These composite particles are widely used in the environmental or medical fields, have been proven to contain no toxicity, and have no risk of causing secondary pollution [ 35 ]. When assembled with the nanoparticle described above, the stabilizing aqueous foam demonstrates a bi-functional property that involves a mass barrier of molecular VOCs, as well as VOC degradation.…”

An Updated Review on Silver Nanoparticles in Biomedicine

“…No toxic or genotoxic effects were identified in fibroblast cultures treated with nanoparticles coated with silica (SiO 2 ) [ 56 ]. In a comparative study, Verkhovskii et al reported that highly stable AgNPs coated with PVA and sodium carboxymethyl cellulose (CMC) are safe for dermal fibroblasts, while nanoparticles coated with sodium dodecyl sulfate and sodium oleate proved cytotoxic [ 57 ].…”