Evaluation of cytotoxic,genotoxic and inflammatory response in human alveolar and bronchial epithelial cells exposed to titanium dioxide nanoparticles |
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Authors: | Cinzia Lucia Ursini Delia Cavallo Anna Maria Fresegna Aureliano Ciervo Raffaele Maiello Paola Tassone Giuliana Buresti Stefano Casciardi Sergio Iavicoli |
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Affiliation: | INAIL – Italian Workers’ Compensation Authority – Research Area, Department of Occupational Medicine, Monteporzio Catone, Rome, Italy |
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Abstract: | The toxicity of titanium dioxide nanoparticles (TiO2‐NPs), used in several applications, seems to be influenced by their specific physicochemical characteristics. Cyto‐genotoxic and inflammatory effects induced by a mixture of 79% anatase/21% rutile TiO2‐NPs were investigated in human alveolar (A549) and bronchial (BEAS‐2B) cells exposed to 1–40 µg ml–1 30 min, 2 and 24 h to assess potential pulmonary toxicity. The specific physicochemical properties such as crystallinity, NP size and shape, agglomerate size, surface charge and specific surface area (SSA) were analysed. Cytotoxic effects were studied by evaluating cell viability using the WST1 assay and membrane damage using LDH analysis. Direct/oxidative DNA damage was assessed by the Fpg‐comet assay and the inflammatory potential was evaluated as interleukin (IL)‐6, IL‐8 and tumour necrosis factor (TNF)‐α release by enzyme‐linked immunosorbant assay (ELISA). In A549 cells no significant viability reduction and moderate membrane damage, only at the highest concentration, were detected, whereas BEAS‐2B cells showed a significant viability reduction and early membrane damage starting from 10 µg ml–1. Direct/oxidative DNA damage at 40 µg ml–1 and increased IL‐6 release at 5 µg ml–1 were found only in A549 cells after 2 h. The secretion of pro‐inflammatory cytokine IL‐6, involved in the early acute inflammatory response, and oxidative DNA damage indicate the promotion of early and transient oxidative‐inflammatory effects of tested TiO2‐NPs on human alveolar cells. The findings show a higher susceptibility of normal bronchial cells to cytotoxic effects and higher responsiveness of transformed alveolar cells to genotoxic, oxidative and early inflammatory effects induced by tested TiO2‐NPs. This different cell behaviour after TiO2‐NPs exposure suggests the use of both cell lines and multiple end‐points to elucidate NP toxicity on the respiratory system. Copyright © 2014 John Wiley & Sons, Ltd. |
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Keywords: | nanosized TiO2 direct‐oxidative DNA damage comet assay cytotoxicity cytokine release |
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