Potential dual imaging nanoparticle: Gd₂O₃ nanoparticle

Gadolinium (Gd) is a unique and powerful element in chemistry and biomedicine which can be applied simultaneously to magnetic resonance imaging (MRI), X-ray computed tomography (CT), and neutron capture therapy for cancers. This multifunctionality can be maximized using gadolinium oxide (Gd₂O₃) nanoparticles (GNPs) because of the large amount of Gd per GNP, making both diagnosis and therapy (i.e., theragnosis) for cancers possible using only GNPs. In this study, the T₁ MRI and CT dual imaging capability of GNPs is explored by synthesizing various iodine compound (IC) coated GNPs (IC-GNPs). All the IC-GNP samples showed stronger X-ray absorption and larger longitudinal water proton relaxivities (r₁ = 26-38 s^-1mM^-1 and r₂/r₁ = 1.4-1.9) than the respective commercial contrast agents. In vivo T₁ MR and CT images of mice were also acquired, supporting that the GNP is a potential dual imaging agent.