Low-Frequency Dynamic Magnetic Fields Decrease Cellular Uptake of Magnetic Nanoparticles

Magnetic nanoparticles have gained attention as a potential structure for therapy and diagnosing oncological diseases. The key property of the magnetic nanoparticles is the ability to respond to an external magnetic field. It is known that magnetofection causes an increase in the cellular uptake of RNA and DNA in complexes with magnetic nanoparticles in the presence of a permanent magnetic field. However, the influence of a dynamic magnetic field on the internalization of MNPs is not clear. In this work, we propose the idea that applying external low-frequency dynamic magnetic fields may decrease the cellular uptake, such as macrophages and malignant neuroblastoma. Using fluorescence microscopy and atomic emission spectroscopy, we found that oscillating magnetic fields decreased the cellular uptake of magnetic nanoparticles compared to untreated cells by up to 46%. In SH-SY5Y tumor cells and macrophage RAW264.7 cells, the absolute values of Fe per cell differed by 0.10 pg/cell and 0.33 pg/cell between treated and untreated cells, respectively. These results can be applied in the control of the cellular uptake in different areas of biomedicine.