Synthesis and characterization of multifunctional iron oxide nanoparticles

In order to get high water solubility, monodisperse, superparamagnetic nanoparticles, poly (acrylic acid) was employed to modify Fe3O4 by a high-temperature solution-phase hydrolysis approach. Then, folic acid (FA) and fluorescein isothiocyanate were successively conjugated with prepared magnetic nanoparticles (MNPs). The functional MNPs were characterized by X-ray diffraction (XRD), dynamic light scattering (DLS), transmission electron microscope (TEM), inductively coupled plasma-atomic emission spectrometer (ICP-AES), and vibrating sample magnetometer (VSM), respectively. The toxicity of the materials was evaluated by selecting NIH/3T3 fibroblast cells and no toxic effect was observed. The fluorescent imaging and targeting property of the MNPs were also realized in vitro and in vivo experiments by confocal laser scanning microscopy (CLSM) and Kodak In-Vivo FX Professional Imaging System, respectively. The results indicated that the final products exhibited interesting magnetic, optical and targeting properties for further potential applications in biological and biomedical fields.