Visualization of the features of the distribution and accumulation of iron nanoparticles in human breast cancer cells sensitive and resistant to antitumor drugs after cultivation with liposomal ferromagnetic during various time intervals

MCF-7 human breast cancer cells sensitive and resistant to cisplatin and doxorubicin were used in experiments. Various cultivation times of these cells in the presence of iron nanoparticles were used for the study. The potentialities of light optical visualization and also the peculiarities of the distribution, localization, and the dynamics of the accumulation of the liposomal form of ferromagnetic in cells have been studied. Based on an analysis of the data obtained in the experiments, we supposed that the most possible route for the inflow of iron nanoparticles into the examined cells is receptor mediated endocytosis, because after a 24-h incubation period, the incorporated iron is in the shape of separated granules localized near the cytoplasmic membrane. In addition, after 24 and 48 hours of cultivation, we discovered an increase in the number of ironpositive cells, as well as an increase in the percentage of tumor cells with a high ferromagnetic content due to the formation of dense structures characterized by cytoplasmic and perinuclear localization. It has been proved that the dynamics of the ferromagnetic accumulation and release from the cells are connected with their resistance to antitumor drugs and with their cultivation time in the presence of iron nanoparticles.