Effects of Fe(3)O(4) Magnetic Nanoparticles on A549 Cells

Fe(3)O(4) magnetic nanoparticles (MgNPs-Fe(3)O(4)) are widely used in medical applications, including magnetic resonance imaging, drug delivery, and in hyperthermia. However, the same properties that aid their utility in the clinic may potentially induce toxicity. Therefore, the purpose of this study was to investigate the cytotoxicity and genotoxicity of MgNPs-Fe(3)O(4) in A549 human lung epithelial cells. MgNPs-Fe(3)O(4) caused cell membrane damage, as assessed by the release of lactate dehydrogenase (LDH), only at a high concentration (100 μg/mL); a lower concentration (10 μg/mL) increased the production of reactive oxygen species, increased oxidative damage to DNA, and decreased the level of reduced glutathione. MgNPs-Fe(3)O(4) caused a dose-dependent increase in the CD44(+) fraction of A549 cells. MgNPs-Fe(3)O(4) induced the expression of heme oxygenase-1 at a concentration of 1 μg/mL, and in a dose-dependent manner. Despite these effects, MgNPs-Fe(3)O(4) had minimal effect on cell viability and elicited only a small increase in the number of cells undergoing apoptosis. Together, these data suggest that MgNPs-Fe(3)O(4) exert little or no cytotoxicity until a high exposure level (100 μg/mL) is reached. This dissociation between elevated indices of cell damage and a small effect on cell viability warrants further study.