Synthesis, characterization and in vitro analysis of α-Fe2O3-GdFeO3 biphasic materials as therapeutic agent for magnetic hyperthermia applications

The use of gadolinium orthoferrite for biomedical application like as contrast agents for magnetic resonance imaging (MRI) has been found to be very promising due to its fascinating properties. The present study focuses on the determination of the effect of the gadolinium concentration in the formation biphasic α-Fe2O3-GdFeO3 for hyperthermia applications. An in-situ sol-gel technique was adopted for the synthesis of biphasic orthoferrites with four different gadolinium concentrations. The XRD analysis confirmed the formation of gadolinium orthoferrites after heat treatment at 1000 °C, 1100 °C, and 1200 °C. The presence of α-Fe2O3 in trace amounts was observed in the materials with low gadolinium concentrations. VSM (Vibrating-sample magnetometer) analysis was performed to ensure the magnetic properties of the materials, which were found to be weakly ferromagnetic. The biocompatibility of the materials was investigated through MTT assay and no cytotoxic effect was observed. The assessment of heating ability of the materials was performed under an alternating magnetic field using an induction heating instrument and all the samples showed temperature rise in the range of hyperthermia temperature with a maximum temperature of 55.71 °C in 6 min. The heating experiments at 44 °C in the absence of samples established the vulnerability of cancer cells as compared to normal cells.