Gadolinium-Coated Mesoporous Silica Nanoparticle for Magnetic Resonance Imaging

Magnetic resonance molecular imaging can provide anatomic, functional and molecular information. However, because of the intrinsically low sensitivity of magnetic resonance imaging (MRI), high-performance MRI contrast agents are required to generate powerful image information for image diagnosis. Herein, we describe a novel T 1 contrast agent with magnetic-imaging properties facilitated by the gadolinium oxide (Gd 2 O 3 ) doping of mesoporous silica nanoparticles (MSN). The size, morphology, composition, MRI relaxivity ( r 1 ), surface area and pore size of these nanoparticles were evaluated following their conjugation with Gd 2 O 3 to produce Gd 2 O 3 @MSN. This unique structure led to a significant enhancement in T 1 contrast with longitudinal relaxivity ( r 1 ) as high as 51.85 ± 1.38 mM −1 s −1 . Gd 2 O 3 @MSN has a larger T 1 relaxivity than commercial gadolinium diethylene triamine pentaacetate (Gd-DTPA), likely due to the geometrical confinement effect of silica nanoparticles. These results suggest that we could successfully prepare a novel high-performance T 1 contrast agent, which may be a potential candidate for in-vivo MRI.