Effect of gamma irradiation on magnetic gadolinium oxide nanoparticles coated with chitosan (GdNPs-Cs) as contrast agent in magnetic resonance imaging

Abstract

This study elucidates a gamma irradiation-reduction approach in producing small gadolinium nanoparticles specifically gadolinium oxide nanoparticles coated with chitosan (GdNPs-Cs). Chitosan was used as a natural stabilizer and coating agent, whereas gadolinium (III) chloride hexahydrate (GdCl3.6H2O) was used as a precursor. The gadolinium nanoparticle was synthesized via hydrothermal method prior to chitosan coating and gamma irradiation. The properties of the synthesized GdNPs-Cs were studied in term of molecular conformation, surface plasmon resonance and particle distribution via ultraviolet–visible spectroscopy (UV–Vis), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR) characterization. Formation of two new UV–Vis peaks at 260 nm and 290 nm depicts the chemical changes of chitosan post gamma irradiation with visible surface plasmon resonance band correlating the reduction of nanoparticle size. Further analysis via TEM demonstrates that synthesized GdNPs-Cs had an average diameter size in the range of 30–45 nm post gamma irradiation, a reduction of size in comparison with control GdNPs-Cs of 120 nm particle size. Enhancement of T1 image obtained via magnetic resonance imaging (MRI) testing proved the capability of synthesized GdNPs-Cs as a contrast agent. Coherently, gamma irradiation-reduction method may be used in controlling the size of nanoparticle and potentially be applied in all major fields related to gadolinium nanoparticle.