Abstract
Silica nanoparticles (SiO&sub2; NPs) represent environmentally born nanomaterials that are used in multiple biomedical applications. Our aim was to study the amorphous SiO&sub2; NP-induced inflammatory response in MRC-5 human lung fibroblasts up to 72 hours of exposure. The intracellular distribution of SiO&sub2; NPs was measured by transmission electron microscopy (TEM). The lactate dehydrogenase (LDH) test was used for cellular viability evaluation. We have also investigated the lysosomes formation, protein expression of interleukins (IL-1β, IL-2, IL-6, IL-8, and IL-18), COX-2, Nrf2, TNF-α, and nitric oxide (NO) production. Our results showed that the level of lysosomes increased in time after exposure to the SiO&sub2; NPs. The expressions of interleukins and COX-2 were upregulated, whereas the expressions and activities of MMP-2 and MMP-9 decreased in a time-dependent manner. Our findings demonstrated that the exposure of MRC-5 cells to 62.5 µg/mL of SiO&sub2; NPs induced an inflammatory response.