Wüstite-type Fe0.78Mn0.22O nanocubes:A new class for high-sensitive T2-weighted magnetic resonance imaging agent

摘要

Wüstite-type Fe(0.78)Mn(0.22)O nanocubes,with a uniform size of^10 nm in edge length,have been synthesized by thermal-decomposition approach.The nanocubes exhibited superparamagnetic properties at room temperature,associated with a magnetization of 12.6 emu/g.These Fe(0.78)Mn(0.22)O nanocubes present transversal(r2)and longitudinal(r1)relaxivities of 325.9 and 0.518 mM^-1 s^-1 at 7 T for water protons.The ratio of the r2/r1(629.2)ranks them being the highest sensitivity(r2/r1)comparable to currently reported T2-weighted magnetic resonance imaging(MRI)agents.Meanwhile,the Fe(0.78)Mn(0.22)O nanocubes were functionalized and demonstrated to be biocompatible when attached to the surface of mesenchymal stem cells,therefore showing the promise as a new class of MRI agents in clinic applications.