Evaluation of Magnetic Hyperthermia Efficiency of PEG-Coated Fe3O4 Nanoparticles

Magnetic nanoparticle hyperthermia has drawn considerable interest in cancer therapy. In this study, we report the synthesis of PEG-coated Fe3O4 nanoparticles and evaluate their suitability for magnetic hyperthermia applications. Fe3O4 nanoparticles were synthesized by the chemical coprecipitation method, which are coated with polyethylene glycol (PEG). PEG-coated Fe3O4 nanoparticles were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM), dynamic light scattering (DLS) and transmission electron microscopy (TEM). Synthesized nanoparticles possess inverse-spinel structural with a crystallite size of 9.1nm. From the M-H hysteresis loops, it was confirmed that the synthesized Fe3O4 nanoparticles were superparamagnetic. The physical size of bare Fe3O4 nanoparticles, as determined from the HR-TEM, is 9.5 +/- 0.12nm, and the corresponding hydrodynamic size of PEG-coated Fe3O4 nanoparticles is 118 +/- 0.25nm. Magnetic hyperthermia efficiency of PEG-coated Fe3O4 nanoparticles was determined as a function of magnetic field frequency (162-935.6kHz), field strength (5-12mT) and nanoparticle concentration (1-100mg/mL). Temperature rise in an aqueous dispersion of PEG-coated Fe3O4 nanoparticles was measured for 20min. The specific loss power (SLP) was calculated by the corrected slope method. SLP values of PEG-coated Fe3O4 nanoparticles increase with magnetic field frequency and field strength and decrease with nanoparticle concentration. The optimum hyperthermia performance of PEG-coated Fe3O4 nanoparticles was observed for 935.6kHz frequency, 10mT field strength and 25mg/mL concentration. Under these conditions, the measured SLP of PEG-coated Fe3O4 nanoparticles was 4.43W/g. These results show that the synthesized PEG-coated Fe3O4 nanoparticles could be a potential candidate for magnetic hyperthermia treatment of cancer.