Synthesis and characterization of glycyrrhizic acid coated iron oxide nanoparticles for hyperthermia applications.

In the present study, iron oxide magnetic nanoparticles (IONPs) were synthesized using the oxidative precipitation method for biomedical applications. Glycyrrhizic acid (GA) extracted from the roots of licorice plant was used as the coating agent for the synthesized nanoparticles (GAIONPs). The crystal phase, morphology and size were investigated by XRD, FE-SEM and TEM. The saturation magnetization (ms) value of the nanoparticles was measured by VSM indicating lowered ms of the GAIONPs with respect to that of the IONPs due to the presence of GA. In addition, the specific loss power of nanoparticles in a solution and in a tissue mimicking phantom was measured using an alternating magnetic field generator. The presence of the GA on the crystal surface was further confirmed using FT-IR and TG/DTA measurements. The specific surface area of the nanoparticles was measured by BET indicating that GA coating agent increases the available active surface area of the nanoparticles for about 25% making it more appropriate for drug loading purposes. The cytotoxicity of the nanoparticles was investigated using MTT assay on L929 fibroblast cell line and the results demonstrated that the coating agent enhances the biocompatibility of the IONPs. The effectiveness of the nanoparticles in inducing cell death was also assessed in an in vitro hyperthermia process and the results showed that the nanoparticles are appropriate to be used for cancer treatment based on hyperthermia.