Superparamagnetic iron oxide nanoparticles (SPIONs): Green preparation, characterization and their cytotoxicity effects

Superparamagnetic iron oxide nanoparticles (SPIONs; Fe3O4) were prepared by the covalent binding of starch onto the surface of magnetic Fe3O4 nanoparticles, by a “green” co–precipitation method. The scanning electron microscopy (SEM) illustrated the regular spheres of Fe3O4 particles that were coated by starch molecules to be regular spheres with a mean diameter of about 40 nm. Powder X–ray diffraction patterns (PXRD) indicated that the prepared samples were pure Fe3O4 with a spinel structure while the coating of starch did not result in a phase change. The starch coating onto the Fe3O4 nanoparticles was also demonstrated by Fourier transform infrared (FTIR) spectra. Magnetic measurements revealed that the saturated magnetization of the starch–SPIONs reached 42.1 emu/g, having nanoparticles with the characteristics of superparamagnetism, while a dose dependent toxicity with non–toxic effect of concentration below 62.5 µg/mL was observed in the studies of in vitro cytotoxicity on neuro2A cells.