Cerium dioxide (CeO2) nanoparticles decrease arsenite (As(III)) cytotoxicity to 16HBE14o- human bronchial epithelial cells

Abstract

The production and application of engineered nanoparticles (NPs) are increasing in demand with the rapid development of nanotechnology. However, there are concerns that some of these novel materials could lead to emerging environmental and health problems. Some NPs are able to facilitate the transport of contaminants into cells/organisms via a “Trojan Horse” effect which enhances the toxicity of the adsorbed materials. In this work, we evaluated the toxicity of arsenite (As(III)) adsorbed onto cerium dioxide (CeO2) NPs to human bronchial epithelial cells (16HBE14o-) using the xCELLigence real time cell analyzing system (RTCA). Application of 0.5 mg/L As(III) resulted in 81.3% reduction of cell index (CI, an RTCA measure of cell toxicity) over 24 h when compared to control cells exposed to medium lacking As(III). However, when the cells were exposed to 0.5 mg/L As(III) in the presence of CeO2 NPs (250 mg/L), the CI was only reduced by 12.9% compared to the control. The CeO2 NPs had a high capacity for As(III) adsorption (20.2 mg/g) in the bioassay medium, effectively reducing dissolved As(III) in the aqueous solution and resulting in reduced toxicity. Transmission electron microscopy was used to study the transport of CeO2 NPs into 16HBE14o- cells. NP uptake via engulfment was observed and the internalized NPs accumulated in vesicles. The results demonstrate that dissolved As(III) in the aqueous solution was the decisive factor controlling As(III) toxicity of 16HBE14o- cells, and that CeO2 NPs effectively reduced available As(III) through adsorption. These data emphasize the evaluation of mixtures when assaying toxicity.

Unravelling the Potential Cytotoxic Effects of Metal Oxide Nanoparticles and Metal(Loid) Mixtures on A549 Human Cell Line

“…It is noteworthy to mention that, according to the results presented in Figure 10A, the sub-G1 phase caused by exposure to a concentration of 20 µg/L Hg alone is significantly decreased by co-exposure with CeO 2 NP, indicating a possible long-term protective effect of this material in A549 cells. CeO 2 NP, at low concentration, have been described to exert a cytoprotective effect by other authors [37,38].…”

“…Cell viability was first assessed after exposure of A549 cells to the individual substances. The range of concentrations chosen intends to be realistic, based on current estimations of these contaminants in the environment [37,38].…”

Genetic Variation in Surfactant Protein-A2 Delays Resolution of Eosinophilia in Asthma

“…Cytotoxicity assay by real-time impedance tracing. Real-time monitoring of eosinophil detachment and cell death were assessed by measuring electrical impedance using the xCELLigence Real-Time Cell Analyzer (ACEA Biosciences, San Diego, CA) as previously described (26,27). Briefly, media were placed in 96-well gold electrode-coated plates (E-plates; ACEA Biosciences)and allowed to equilibrate, and a background reading was obtained.…”

“…Eosinophils were then seeded at 1 3 10 6 cells/100 ml and allowed to settle for ∼ 5 h. SP-A was added at various concentrations, and changes in electrical impedance were measured over time. Impedance measurements, presented as a normalized "cell index," are calculated as detailed (26,27). Under these conditions, a loss of cell index is associated with eosinophil detachment and cytotoxicity.…”

Cytotoxicity Assessment of Gallium- and Indium-Based Nanoparticles Toward Human Bronchial Epithelial Cells Using an Impedance-Based Real-Time Cell Analyzer

“…20,40,41 The cells were initially grown as previously described. 34,42 Firstly, cells were grown in tissue culture flasks coated with a collagen/fibronectin/ bovine serum albumin (CFB) matrix in a controlled growth medium that contains minimum essential medium (MEM) supplemented with 10% (vol/vol) fetal bovine serum (FBS), 2 mM GlutaMAX, penicillin, and streptomycin at 37 C in a 5% CO 2 atmosphere. Next, the cells were transferred to RTCA assay plates coated with CFB and maintained with a reduced serum (5% FBS) medium.…”