Chitosan-stabilized iron oxide nanoparticles for magnetic resonance imaging

Abstract

Abstract The iron oxide nanoparticles were synthesized by the co-precipitation method and consequently stabilized by a chitosan coating. The characterization of the chitosan modified nanoparticles was performed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), dynamic light scattering (DLS), SQUID magnetometer and MRI analysis. The particle size and ζ-potential measurement, the measured hydrodynamic diameter of chitosan modified magnetic nanoparticles was equal to 136.1 nm, while the ζ-potential is +48 mV. The superparamagnetic behaviour of both unmodified and chitosan modified Fe3O4 nanoparticles at room temperature was confirmed using a SQUID magnetometer. Finally, the relaxation times (T1 and T2) were measured by MRI. From the result of magnetic resonance imaging (MRI) analysis, the relaxation rate (R) and relaxivity (r) have been calculated: r 1 = 0.713 mM−1 s−1, r 2 = 238.16 mM−1 s−1 and r 2 ∗ = 276.1 mM−1 s−1. An acquired high r2/r1 ratio (3 3 4) indicates that the prepared nanoparticles have a significant prevailing effect on the transversal relaxation time (T2) in comparison to the longitudinal relaxation time (T1). These results demonstrate the potential usefulness of chitosan-stabilized iron oxide nanoparticles as a contrast agent for MRI.