Cytotoxicity and Genotoxicity of Ceria Nanoparticles on Different Cell Lines in Vitro

Abstract

Owing to their radical scavenging and UV-filtering properties, ceria nanoparticles (CeO2-NPs) are currently used for various applications, including as catalysts in diesel particulate filters. Because of their ability to filter UV light, CeO2-NPs have garnered significant interest in the medical field and, consequently, are poised for use in various applications. The aim of this work was to investigate the effects of short-term (24 h) and long-term (10 days) CeO2-NP exposure to A549, CaCo2 and HepG2 cell lines. Cytotoxicity assays tested CeO2-NPs over a concentration range of 0.5 μg/mL to 5000 μg/mL, whereas genotoxicity assays tested CeO2-NPs over a concentration range of 0.5 μg/mL to 5000 μg/mL. In vitro assays showed almost no short-term exposure toxicity on any of the tested cell lines. Conversely, long-term CeO2-NP exposure proved toxic for all tested cell lines. NP genotoxicity was detectable even at 24-h exposure. HepG2 was the most sensitive cell line overall; however, the A549 line was most sensitive to the lowest concentration tested. Moreover, the results confirmed the ceria nanoparticles’ capacity to protect cells when they are exposed to well-known oxidants such as H2O2. A Comet assay was performed in the presence of both H2O2 and CeO2-NPs. When hydrogen peroxide was maintained at 25 μM, NPs at 0.5 μg/mL, 50 μg/mL, and 500 μg/mL protected the cells from oxidative damage. Thus, the NPs prevented H2O2-induced genotoxic damage.

Toxicity and Protective Effects of Cerium Oxide Nanoparticles (Nanoceria) Depending on Their Preparation Method, Particle Size, Cell Type, and Exposure Route

“…In fact, they observed that ceria had different effects according to the cell line of interest, the human adenocarcinomic alveolar basal epithelial A549 cell line being the most sensitive to the presence of ceria at low concentrations. Three different studies on nanoceria toxicity against A549 cells (Table 1) all demonstrated adverse effects [12,41,42] and are thus in accordance with the observations of De Marzi et al, [22] who did not observe any toxic effect of ceria after 24 hours of exposure but reported a genotoxic effect for all cell lines after 10 days.…”

“…[20] This leads to the protection of eukaryotic cells against oxidative stress, as it was previously reported in many studies. [21,22] Niu et al [23] and Korsvik et al [24] have proposed a mechanism, shown in Equations (2) and (3), by which ceria can scavenge radicals thanks to its redox potential.…”

“…[37] Some publications reported a time-and dose-dependent toxicity of ceria nanomaterials. [38][39][40] De Marzi et al, [22] who studied the one-day and ten-day effects of ceria exposure on different cell lines, found that the toxicity assays are greatly dependent on the systems being studied. In fact, they observed that ceria had different effects according to the cell line of interest, the human adenocarcinomic alveolar basal epithelial A549 cell line being the most sensitive to the presence of ceria at low concentrations.…”

Cerium dioxide nanoparticles selectively up-regulate C-C chemokine receptor 2 and CD16 expression on human monocytes

“…Indeed, our results in the present work (Fig S1), as well as many of the previously cited reports, show no toxicity in different cell lines, even at high concentrations. Often, toxic or not toxic effects have been observed in different cell types (Chen, 2013;Hussain, 2012;Sabella 2014) and different time of nanoparticle exposure (De Marzi, 2013). Their involvement in anti-inflammatory (Hirst, 2009) or pro-inflammatory immune responses has been also shown, even if a pro-inflammatory role in vivo is becoming evident by several studies (Demokritou, 2013;Peng, 2013;Poma, 2014;Xue, 2013).…”

Immunotoxicological impact of occupational and environmental nanoparticles exposure: The influence of physical, chemical, and combined characteristics of the particles

“…Consequently, the smaller the NPS, the higher the oxidative stress they induce. 85,86 Moon et al examined acute pulmonary responses in an animal study after intraperitoneal administration of TiO 2 NPs, at rest or in lungs primed with lipopolysaccharide. TiO 2 exposure increased neutrophil influx, protein levels in bronchoalveolar lavage fluid, ROS activity of BAL cells 4 h after exposure.…”