Purpose: The purpose of this study was to closely investigate the effects of heat dissipation of superparamagnetic nanoparticles on HCT-116 human cancer cell lines cultured under laboratory conditions and also to examine important parameters including size and concentration of nanoparticles, magnetic field frequency, magnetic field intensity, and exposure time.
Materials and methods: Conducting experimental tests required special hardware capable of producing an AC magnetic field with various frequencies. The design and construction process for such an experimental set-up is presented here. First, three different Fe3O4 nanoparticle sizes (8, 15 and 20 nm) with different concentrations (d = 10, 20, 40, 80, 160 and 200 µg/ml) were added to cell culture medium and the resulting mixture was exposed to an AC magnetic field with maximum amplitude of 10 kOe for 30 min under three operating frequencies (f = 80, 120 and 180 kHz). The level of intracellular iron was estimated by the ferrozine-based colorimetric assay. Three concentrations including 20, 40 and 80 µg/ml from each of the three nanoparticles sizes were chosen for the study.
Results: It was shown that the power dissipation is a function of frequency, time, nanoparticles size and dose. It was also found that the alternating magnetic field with three different frequencies (f = 80, 120 and 180 kHz) and the maximum amplitude of 10 kOe did not have any adverse effect on cell survival.
Conclusions: Our results demonstrate that where thermal dose is equal to 4.5 ± 0.5 °C/30 min from a starting temperature of 37 °C, HCT-116 cell death is initiated when a magnetic nanoparticle electromagnetic field induced.
Keywords: Cancer cell line; electromagnetic field; hyperthermia; magnetic nanoparticles; thermal dose.