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

Abstract

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(O₂C^tBu)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.