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Zijno A.,Istituto Superiore di Sanita | De Angelis I.,Istituto Superiore di Sanita | De Berardis B.,Istituto Superiore di Sanita | Andreoli C.,Istituto Superiore di Sanita | And 7 more authors.
Toxicology in Vitro | Year: 2015

In this work we investigated the genotoxicity of zinc oxide and titanium dioxide nanoparticles (ZnO NPs; TiO2 NPs) induced by oxidative stress on human colon carcinoma cells (Caco-2 cells). We measured free radical production in acellular conditions by Electron Paramagnetic Resonance technique and genotoxicity by micronucleus and Comet assays. Oxidative DNA damage was assessed by modified Comet assay and by measuring 8-oxodG steady state levels. The repair kinetics of DNA oxidation as well as the expression levels of hOGG1 were also analyzed. Even if both NPs were able to produce ROS in acellular conditions and to increase 8-oxodG levels in Caco-2 cells, only ZnO NPs resulted genotoxic inducing micronuclei and DNA damage. Furthermore, Caco-2 cells exposed to ZnO NPs were not able to repair the oxidative DNA damage that was efficiently repaired after TiO2 NPs treatment, through OGG1 involvement. These results indicate that the high oxidant environment caused by ZnO NPs in our cellular model can induce DNA damage and affect the repair pathways. © 2015 Elsevier Ltd.

De Angelis I.,Istituto Superiore di Sanita | Barone F.,Istituto Superiore di Sanita | Zijno A.,Istituto Superiore di Sanita | Bizzarri L.,Istituto Superiore di Sanita | And 8 more authors.
Nanotoxicology | Year: 2013

Despite human gastrointestinal exposure to nanoparticles (NPs), data on NPs toxicity in intestinal cells are quite scanty. In this study we evaluated the toxicity induced by zinc oxide (ZnO) and titanium dioxide (TiO2) NPs on Caco-2 cells. Only ZnO NPs produced significant cytotoxicity, evaluated by two different assays. The presence of foetal calf serum in culture medium significantly reduced ZnO NPs toxicity as well as ion leakage and NP-cell interaction. The two NPs increased the intracellular amount of reactive oxygen species (ROS) after 6 h treatment. However, only ZnO NPs increased ROS and induced IL-8 release both after 6 and 24 h. Experimental data indicate a main role of chemical composition and solubility in ZnO NPs toxicity. Moreover our results suggest a key role of oxidative stress in ZnO NPs cytotoxicity induction related both to ion leakage and to cell interaction with NPs in serum-free medium. © 2013 Informa UK, Ltd.

Cresti R.,National Center for Chemicals | Cabella R.,National Center for Chemicals | Attias L.,National Center for Chemicals | Rubbiani M.,National Center for Chemicals
International Journal of Environment and Health | Year: 2011

The assessment of occupational exposure following disinfection of hard surfaces with a biocidal product based on didecyldimethylammonium chloride (DDAC) was carried out for both spraying and wiping-off applications. Several human exposure models were used, and the results were compared, in order to figure out the differences and identify the most representative model. No risk management measurements were considered. For dermal exposure, models produced similar results except for ConsExpo 4.1 ('instant application' mode) and RISKOFDERM for spraying and wiping. As regards inhalation exposure, only some models take the inhalation route into account. In these cases, levels proved to be negligible or to contribute to the total systemic dose by <2%. None of the investigated models could be concluded to be the best candidate for the assessment of professional exposure to hard surface disinfectants. This paper highlights the necessity of additional monitoring studies for the measurement of the actual exposure for the investigated scenarios. Copyright © 2011 Inderscience Enterprises Ltd.

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