Preparation of highly dispersed γ-Fe2O3 and GdPO4 co-functionalized mesoporous carbon spheres for dual-mode MR imaging and anti-cancer drug carrying.

There is great interest in integration of paramagnetic gadolinium compounds and superparamagnetic iron oxide-based nanoparticles into ordered mesoporous carbon spheres (OMCSs) as a combined platform for T1- and T2-weighted magnetic resonance (MR) imaging and drug carrying. In this work, highly dispersed γ-Fe2O3 and GdPO4 nanoparticle co-functionalized mesoporous carbon spheres were successfully prepared using a 3d-4f heterometallic cluster of [Fe6Gd6(μ3-O)2(CO3)(O3PPh)6(O2CtBu)18] as the precursor. The study reveals that multi-scale confinement effects play a role in concurrent generation of Fe and Gd nanoparticles in the carbon matrix. In addition, dual-mode MR imaging and drug carrying properties were evaluated by in vitro experiments, showing satisfactory r1 and r2 relaxivity values of 8.2 and 94.3 mM-1 s-1, respectively, and doxorubicin hydrochloride (DOX) carrying amount of 132 mg g-1, suggesting potential as a combined system for diagnosis and therapy.