The health risk and cytotoxic effects of nanoparticles are almost unknown. Consequently, we have launched an interdisciplinary research program to systematically investigate the toxicity of nanoparticles. An initial observation prompted us to hypothesize that SiO2 nanoparticles can traverse the plasma membranes of cells through the endocytosis mechanism and thereby exert their cellular and cytotoxic effects on cells. To test this hypothesis, we investigated the effects of silicon dioxide nanoparticles on two human brain tumor cell lines (SK-N-SH, a neuroblastoma line and U87, an astrocytoma line) employing light microscopy, lactate dehydrogenase release into the culture medium (an indicator of cell damage and necrosis) and MTT assay (an indicator of cell survival). Our results indicate exposure to SiO2 nanoparticles led to cytotoxic damage (as indicated by LDH release) and decreases in cell survival (as determined by the MTT assay) in SK-N-SH and U87 cells in a dose-related manner, their effect being more pronounced in SK-N-SH cells. The morphological changes in these two cell types upon exposing them to the nanoparticles, as observed by bright field light microscopy, were also consistent with the cytotoxicity data. Our findings therefore may have implications in nanotoxicity and health risk of exposure to metallic oxide nanoparticles.
Journal: TechConnect Briefs
Volume: 2, Technical Proceedings of the 2007 NSTI Nanotechnology Conference and Trade Show, Volume 2
Published: May 20, 2007
Pages: 741 - 743
Industry sector: Medical & Biotech