Gadolinium(III)-Incorporated Nanosized Mesoporous Silica as Potential Magnetic Resonance Imaging Contrast Agents

A new class of potential magnetic resonance imaging contrast agents with nanosized mesoporous silica as the metal carrier is reported. Gadolinium-incorporated mesoporous silicas were synthesized by using long-chain surfactant as a template. The products were characterized with X-ray powder diffraction, nitrogen adsorption−desorption isotherms, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, 29Si-MAS NMR, and proton relaxivity. The materials showed much higher relaxivities, r 1 and r 2, than Gd-DTPA. The particles are nanosized and can enter cells easily. This is a completely novel biomedical application of mesoporous silica materials.