Tumor Microenvironment Responsive Biodegradable Fe-Doped MoOx Nanowires for Magnetic Resonance Imaging Guided Photothermal-Enhanced Chemodynamic Synergistic Antitumor Therapy.

Rational design of nanosystems that target tumor microenvironment have attracted widespread attention. However, it is still a great challenge to make a multifunctional nanoplatform that actively and selectively interacts with tumor microenvironment, without causing toxicity to surrounding normal tissues. Herein, the biodegradable Fe-doped MoOx (FMO) nanowires are designed as an anti-tumor nanoreagent that possesses great photothermal conversion ability (48.5%) and magnetic properties for T1 weighted magnetic resonance imaging (MRI). Also, FMO can be used as a chemodynamic therapy (CDT) reagent to effectively catalyze the decomposition of H2 O2 and produce hydroxyl radical (·OH). At the same time, the consumption of glutathione will also enhance the CDT effect. More importantly, FMO presents pH-dependent degradation behavior: rapid degradation at physiological pH, but relatively stable at acidic pH. In vivo anti-tumor experiment demonstrates that the FMO is able to effectively inhibit the tumor growth with minimal side effects. Generally speaking, these results indicate that the FMO has huge potential for MRI image-guided cancer therapy and promotes the clinical translation of nanodrugs.