The Cytotoxic Effects of Sio2 Nanoparticles on Human Blood Mononuclear Cells

Regarding the increasing use of silicon dioxide nanoparticles in medical biotechnology and probable side effects and diseases resulting from its usage, this study was performed to assess the toxic effects of different concentrations of SiO2 nanoparticles on human blood mononuclear leukocytes using the MTT assay. In this laboratory trial study, we prepared suspensions of blood mononuclear cells from 10 young healthy men and also different concentrations of the nanoparticles (1, 10, 100, 500, 1000 and 1500µg/mL). The cells were then incubated with these nanoparticles for 24 hours at 37 °c, and finally the percent of dead cells were measured by MTT assay kit using spectrophotometer reading at 490 nm after 6 and 24 hours of incubation. Positive and negative controls and blanking were applied, too. A significant difference was found in percent of dead cells between the different concentrations of SiO2 nanoparticles and also between the exposed cells and control group (p<0.05). There was increasing cytotoxicity in 6 hours as well as 24 hours exposure with higher concentrations of the nanoparticles. Cytotoxicity after 24 hours exposure to 10 µg/mL of nanoparticles was about 6 times that of the 1 µg/mL. This study showed for the first time that SiO2 with a concentration of 1 µg/mL has cytotoxicity on human blood mononuclear cells. Cytotoxic effects of this nanoparticle are time- and concentration-dependent.