Non-aqueous to aqueous phase transfer of oleic acid coated iron oxide nanoparticles for hyperthermia application

Iron oxide magnetic nanoparticles (MNPs) alone are suitable for a broad spectrum of applications, but the low stability and heterogeneous size distribution in aqueous medium represent major setbacks. These setbacks can however be reduced or diminished through functionalization of MNPs with various biocompatible surfactants. In this study, magnetite (Fe3O4) nanoparticles were modified using oleic acid (OA) to reduce their agglomeration. To render hydrophilicity and to increase the colloidal stability of the MNPs, they were further functionalized with betaine-HCl (BTH). The physiochemical properties were well characterized using X-ray diffraction, Fourier transform infrared, thermogravimetric analysis, transmission electron microscopy and superconducting quantum interference device of the OA-BTH coated Fe3O4 MNPs in order to use them for hyperthermia application. Zeta potential study and size distribution of nanoparticles showed increased stability of the nanoparticles. The coated MNPs show increase in specific absorption rate value of 91.03 W g(-1) at 335.2 Oe, making them more suitable for hyperthermia application. Cytotoxicity study was performed by MTT assay on L929 cell line for 24 h incubation period.