C.T. Mihai, E. Puscasu, L. Secarescu, C. Nadejde, D. Gherghel, D. Creanga, G. Vochita
Alexandru Ioan Cuza University, Romania
pp. 310 - 313
Keywords: magnetite nanoparticles synthesis, DNA fragmentation, cell apoptosis
Various bioeffects of nanoparticulate matter were reported in the last decades. Herein, we present colloidal magnetic nanoparticles (MNPs), yielded by chemical route, tested for cytotoxicty with focus on cell apoptosis and DNA fragmentation. Chinese hamster lung fibroblast V79 cells were chosen for cytotoxicity assays due to relatively high plating efficiency and short generation time. Oleate ion was chosen to ensure sterical stabilization of MNPs in aqueous suspension due to its strong interactions with iron ions. Dimensional distribution of particle physical diameter revealed maximum incidence of magnetite grains with 12 nm; spinel structure was confirmed by X-ray diffractometry, while superparamagnetic features were evidenced by vibrating sample magnetometry. Small-angle X-ray scattering analysis allowed the evidence of smooth surface spherical grains. The influence of MNPs on cellular DNA was found consistent with up to 50% progressive fragmentation (p < 0.01) for MNP concentration over 100 µg/ml. Flow cytometry data showed that living cells have diminished up to 50%, while dead cells increased more than ten folds (p < 0.01). MNP uptake in the cytoplasm, their digestion with catalytic iron ion release, able of inducing apoptosis by DNA damages following peroxides formation, was the main hypothesis of phenomenological background for the recorded data.