RESUMEN
Magnetic nanoparticles in a variable magnetic field are able to produce heat. This heat [42-45[degree sign]C] has more selective effect on fast dividing cancer cells than normal tissues. In this work magnetite nanoparticles have been prepared via coprecipitation and phase identification was performed by powder x-ray diffraction [XRD]. Magnetic parameters of the prepared nanoparticles were measured by a Vibrating Sample Magnetometer [VSM]. A sensitive thermometer has been used to measure the increase of temperature in the presence of an alternating magnetic field. To evaluate the cytotoxicity of nanoparticles, the suspended magnetite nanoparticles in liquid paraffin, doxorubicin and a mixture of both were added to the MDA-MB-468 cells in separate 15 ml tubes and left either in the RT or in the magnetic field for 30 min. Cell survival was measured by trypan blue exclusion assay and flow cytometer. Particle size distribution of the nanoparticles was homogeneous with a mean particles size of 10 nm. A 15[degree sign]C temperature increase was achieved in presence of an AC magnetic field after 15 min irradiation. Biological results showed that magnetite nanoparticles alone were not cytotoxic at RT, while in the alternative magnetic filed more than 50% of cells were dead. Doxorubicin alone was not cytotoxic during 30 min, but in combination with magnetite more than 80% of the cells were killed. It could be concluded that doxorubicin and magnetite nanoparticles in an AC magnetic field had combinatory effects against cells