In Vitro Studies of Silica Nanomaterials-Induced Toxicity

1 In Vitro Studies of Silica Nanomaterials-induced Toxicity 

The MTT ]3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] and LDH (lactate dehydrogenase) assays are commonly used to evaluate the cytotoxidty of nanomaterials, while measurements of ROS, glutathione (GSH) and hOggl are used to evaluate nanomaterial-induced oxidative stress. The different cell Unes 

Although the toxidties of silica nanomaterials have been investigated widely in vitro, these studies may not reflect the true scenario, as would occur with in vivo exposure. For example, a low efficiency of endocytosis might lead to a low cyto-toxidty in vitro, while severe chronic toxicity may be induced in the evacuation process. Therefore, in vivo studies are necessary in order to evaluate silica nanomaterials-induced toxicity. 

Pulmonary exposure is the most popular route for in vivo investigations of nanomaterials-induced toxidty. In order to better understand the toxic effect of amorphous silica nanomaterials, the nanomaterials were instilled into the respiratory tract [38, 44—46, 100] and, after a period of treatmenf the acute and subacute pulmonary toxic effects were monitored. However, this phenomenon was an induced transient toxicity, and pulmonary function was fully recovered after several days post-exposure. Compared to the persistent pulmonary inflammation caused by crystalline silica nanomaterials, the negative effect of amorphous silica nanomaterials was considered insignificant. 

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