Synthesis of Gd-functionalized Fe3O4@polydopamine nanocomposites for T1/T2 dual-modal magnetic resonance imaging-guided photothermal therapy

Abstract

A safe, efficient and inexpensive multifunctional nanoplatform is urgently needed for cancer diagnosis and treatment. Herein, we report the first example of fabrication of gadolinium-functionalized Fe₃O₄@polydopamine nanocomposites and evaluate their potential application in T₁/T₂ dual-modal magnetic resonance imaging-guided photothermal therapy in vitro. This was achieved by encapsulating iron oxide nanoparticles with polydopamine, and then grafting gadolinium chelates onto the surface of Fe₃O₄@polydopamine nanocomposites. The as-prepared nanocomposites, composed of low cost Fe₃O₄, polydopamine and gadolinium complexes, showed high stability and good biocompatibility. More importantly, these nanocomposites exhibited high photothermal conversion efficiency, with the temperature reaching 43.0 °C at a concentration of 0.35 mg mL⁻¹ under near-infrared irradiation for a few minutes. Furthermore, according to the magnetic resonance imaging results, these nanocomposites could induce an efficient contrast enhancement for both T₁ and T₂ imaging at low concentrations of Gd and Fe. This provides a new platform for the development of new diagnosis and therapeutic agents.