Mixture Effects of Diesel Exhaust and Metal Oxide Nanoparticles in Human Lung A549 Cells

Abstract

Airborne ultrafine particles (UFP) mainly derive from combustion sources (e.g., diesel exhaust particles—DEP), abrasion sources (non-exhaust particles) or from the unintentional release of engineered nanoparticles (e.g., metal oxide nanoparticles—NPs), determining human exposure to UFP mixtures. The aim of the present study was to analyse the combined in vitro effects of DEP and metal oxide NPs (ZnO, CuO) on human lung A549 cells. The mixtures and the relative single NPs (DEP, ZnO, CuO) were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS) and inductively coupled plasma-optic emission spectroscopy (ICP-OES). Cells were exposed for different times (3–72 h) to mixtures of standard DEP at a subcytotoxic concentration and ZnO and CuO at increasing concentrations. At the end of the exposure, the cytotoxicity was assessed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) and clonogenic tests, the pro-inflammatory potential was evaluated by interleukin-8 (IL-8) release and the cell morphology was investigated by fluorescence and transmission electron microscopy. The obtained results suggest that the presence of DEP may introduce new physico-chemical interactions able to increase the cytotoxicity of ZnO and to reduce that of CuO NPs.

Assessment of SnFe2O4 Nanoparticles for Potential Application in Theranostics: Synthesis, Characterization, In Vitro, and In Vivo Toxicity

“…Zerboni and colleagues reported a significant concentration-dependent decrease in the number of viable A549 cells after 24 h and 48 h exposed to CuO NPs at concentrations of 15, 20, and 25 µg/mL. In contrast, ZnO NPs were not able to induce such cytotoxic effects at concentrations less than 25 µg/mL [ 17 ]. Li et al showed that low concentrations of iron oxide-based magnetic NPs markedly diminished the cell viability of A549 cells and exerted noticeable synergistic effects against malignant cells [ 18 ].…”

Czego dowiedzieliśmy się o COVID-19 w 2020 roku? 10 hipotez wyjaśniających różnice w zachorowalności i śmiertelności z powodu COVID-19 między krajami

“…It seems that an atmosphere with a high PM2.5 and PM10 content favours the transmission of the virus by transporting it on dust particles over long distances. PM2.5 and PM10 particles also induce inflammation in the lungs, which may increase the risk of infection and exacerbate the course of COVID-19 [47][48][49][50][51]. The rapid development of the pandemic in Italian Lombardy may also have depended on air pollution in Italian cities in the region [21].…”

Cellular Mechanisms Involved in the Combined Toxic Effects of Diesel Exhaust and Metal Oxide Nanoparticles

“…Commercial CuO (<50 nm, CAS 1317-38-0), ZnO (<50 nm, CAS 1314-13-2), NPs, and diesel exhaust particles (DEPs; NIST SRM ® 2975) were purchased from Sigma-Aldrich (Milan, Italy). Particle suspensions and mixtures were prepared as previously described [8] and characterized (Tables S1 and S2 and Figure S1). The mixtures were freshly prepared before use.…”

“…Human alveolar epithelial cells, A549 (ATCC ® CCL-185, American Type Culture Collection, Manassas, VA, USA), were grown and maintained as previously reported [8]. For the experiments, the cells were seeded at a concentration of 1.6 × 10 4 cells/cm 2 on 6-well plates (Corning ® , Pero (MI), Italy) and grown for 24 h. At the optimal confluence (80-90%), the culture medium was replaced with fresh OptiMEM supplemented with 1% foetal bovine serum (FBS) (Gibco, Life Technologies, Monza, Italy), and the cells were treated by directly adding the different particle suspensions (ZnO, ZnO + DEP, CuO, CuO + DEP, or DEP) into the medium.…”

“…From a perspective of cumulative risk assessment (CRA), it will be important to evaluate the possible interactions between different pollutants, acting on multiple pathways, which could lead to common or different health outcomes. Recently, we presented a study on the combined in vitro effects of DEPs and CuO and ZnO NPs on A549 human lung cells [8]. The data showed that co-exposure to DEPs and NPs may induce physico-chemical interactions between the particles, with consequent increased cytotoxicity for ZnO NPs mixed with DEPs, and reduced effects for CuO NPs when mixed with DEPs.…”