Cytotoxicity and DNA Damage Induced by Magnetic Nanoparticle Silica in L5178Y Cell

As recent reports suggest that nanoparticles may penetrate into cell membrane and effect DNA condition, it is necessary to assay possible cytotoxic and genotoxic risk. Three different sizes of magnetic nanoparticle silica (MNP@ SiO₂ ) (50, 100 and 200 nm diameter) were tested for cytotoxicity and DNA damage using L5178Y cell. MNP@ SiO₂ had constant physicochemical characteristics confirmed by transmission electron microscope, electron spin resonance spectrometer and inductively coupled plasma-atomic emission spectrometer for 48 h. Treatment of MNP@ SiO₂ induced dose and time dependent cytotoxicity. At 6 h, 50, 100 or 200 nm MNP@ SiO₂ decreased significantly cell viability over the concentration of 125 μg/ml compared to vehicle control (p<0.05 or p<0.01). Moreover, at 24 h, 50 or 100 nm MNP@ SiO₂ decreased significantly cell viability over the concentration of 125 μg/ml (p<0.01). And treatment of 200 nm MNP@ SiO₂ decreased significantly cell viability at the concentration of 62.5 μg/ml (p<0.05) and of 125, 250, 500 μg/ml (p<0.01, respectively). Furthermore, at 48 h, 50, 100 or 200 nm MNP@ SiO₂ decreased significantly cell viability at the concentration of 62.5 μg/ml (p<0.05) and of 125, 250, 500 μg/ml (p<0.01, respectively). Cellular location detected by confocal microscope represented they were existed in cytoplasm, mainly around cell membrane at 2 h after treatment of MNP@ SiO₂ . Treatment of 50 nm MNP@ SiO₂ significantly increased DNA damage at middle and high dose (p<0.01), and treatment of 100 nm or 200 nm significantly increased DNA damage in all dose compared to control (p<0.01). Taken together, treatment of MNP@ SiO₂ induced cytotoxicity and enhanced DNA damage in L5178Y cell.