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