Synthesis and characterization of maghemite nanoparticles for hyperthermia applications

Magnetic nanoparticles for hyperthermic treatment of cancers have gained significant attention in recent years. In this work, biocompatible maghemite nanoparticles were synthesized by the oxidation of magnetite nanoparticles, using a coprecipitation method followed by heat treatment at different temperatures ranging from 200 to 300 °C for 3, 5 and 8 hours. The samples were analyzed by X-ray diffraction, vibrating sample magnetometry and transmission electron microscopy. The heating ability was evaluated under a magnetic field using a solid state induction heating equipment. Additionally, hemolysis test was performed. The obtained nanoferrites showed a particle size within the range of 10–11 nm and superparamagnetic behavior. The maghemite obtained at 250 °C for 5 hours was able to heat in concentrations of 13 mg/2 ml under a magnetic field (10.2 kAm−1 and frequency 362 kHz), increasing the temperature up to 49 °C. Hemolysis test, evaluated as release of hemoglobin, revealed that all the samples showed no hemolytic effects up to 3 mg/ml, indicating no damage of the red blood cell membranes. The results indicated that the maghemite nanoparticles obtained might be potential materials for cancer treatment by hyperthermia.