Surface reactivity and in vitro toxicity on human bronchial epithelial cells (BEAS-2B) of nanomaterials intermediates of the production of titania-based composites

Abstract

Titanium dioxide (TiO2) nanoparticles (NPs) are manufactured worldwide in large quantities for use in a wide range of applications. Evaluating the hazards associated with TiO2 NPs is crucial as it enables risk assessment related to human and environmental exposure. In this study the in vitro human toxicity of a set of TiO2 NPs modified with acetic, oleic and boric acids were studied in order to assess the hazard in view of a future scale-up of the synthesis. The surface reactivity of the powders under simulated solar illumination and in the dark has been evaluated by means of EPR spectroscopy. Human bronchial epithelial cells (BEAS-2B) have been chosen as a model for lung epithelium. Cytotoxicity has been assessed by measuring the cells membrane integrity by lactate dehydrogenase (LDH) assay, and the inflammatory response evaluated as nitric oxide (NO) and TNF-α production, and oxidative stress measured as intracellular reduced glutathione (GSH) levels, and induced lipoperoxidation. Aeroxide P25 was used for comparison. The results demonstrated a low photoreactivity and toxic effects lower than Aeroxide P25 of the nano-TiO2 powders, probably as a consequence of the presence of acidic moieties at the surface.

Synthesis and Applications of Nano Titania Particles: A Review

“…This method may be further be classified in to non-hydrolytic and non-aqueous methods. The prior one is based upon the formation of metal oxides by reaction of oxygen containing organic molecules such as organic ethers or metal alkoxide molecules without any involvement of the water molecules in the process, whereas in the later the water molecules are produced insitu and take part in the hydrolysis [23,29,30]. The synthesis of metal oxides from their chlorides such as titanium tetrachloride (TiCl 4 ), vanadium oxytrichloride (VOCl 3 ) and tungsten hexachloride (WCl 6 ) by using anhydrous benzyl alcohol was firstly reported by Niederberger et al [31].…”

Human lung epithelial BEAS-2B cells exhibit characteristics of mesenchymal stem cells

“…Since being labeled as a bronchial epithelial cell line, BEAS-2B has been extensively used to study cellular and molecular mechanisms involved in lung carcinogenesis, including the role of epithelial-mesenchymal transition (EMT) in lung carcinogenesis [2][3][4], as well as pneumococcal infections [5]. In addition, the BEAS-2B cell line has been utilized as an in vitro cell model for assaying or screening various chemicals and biological agents with potential pulmonary toxicity or lung carcinogenicity [6][7][8]. While very few of these studies provided further evidence regarding the expression of proteins, such as vimentin, cytokeratin 8 and E-cadherin [9], to support epithelial essence of BEAS-2B, the vast majority of the studies did not even present concern about the epithelial features of BEAS-2B.…”

The Secretory Response of Rat Peritoneal Mast Cells on Exposure to Mineral Fibers

“…However, recent studies have reported that the degree of toxicity of TiO 2 can depend on physicochemical parameters, such as the morphology of TiO 2 NPs, size, aggregation, crystal phase, and surface modifications [ 3 , 4 , 5 ]. They have been shown to be cytotoxic for both epithelial and inflammatory cells [ 3 , 6 , 7 , 8 ] and induce the production of reactive oxygen species (ROS) from phagocytic cells [ 5 , 6 , 8 , 9 , 10 ]. A cytotoxic effect of TiO 2 NPs for these cells (and fibroblasts) was also shown in other studies [ 11 , 12 , 13 , 14 ].…”

“…It is noteworthy that these experimental models have examined different administration routes, doses employed, time of exposure, and types of TiO 2 NPs [ 20 , 27 ]. Apart from quantitative effects, the qualitative effects of TiO 2 particles of different morphology and structure are very similar in terms of pro-inflammatory (i.e., ROS production, cytokine production, ingestion path) and cytotoxic activity [ 3 , 4 , 8 , 10 , 13 ], even independently of the administration route [ 4 , 12 , 13 , 20 , 27 ]. Interestingly, TiO 2 NPs and nanowires appear to be taken up by inflammatory and epithelial cells through two pathways: endocytosis and penetration, with the latter being suggested by the presence of free cytosolic TiO 2 NPs in the absence of a limiting endosome membrane [ 4 , 6 , 11 , 14 , 28 , 29 ].…”