Supramolecular assembly of Polydopamine@Fe nanoparticles with near-infrared light-accelerated cascade catalysis applied for synergistic photothermal-enhanced chemodynamic therapy

Chemodynamic therapy (CDT) via Fenton-like reaction is greatly attractive owing to its capability to generate highly cytotoxic center dot OH radicals from tumoral hydrogen peroxide (H2O2). However, the antitumor efficacy of CDT is often challenged by the relatively low radical generation efficiency and the high levels of antioxidative glutathione (GSH) in tumor microenvironment. Herein, an innovative photothermal Fenton-like catalyst, Fechelated polydopamine (PDA@Fe) nanoparticle, with excellent GSH-depleting capability is constructed via one-step molecular assembly strategy for dual-modal imaging-guided synergetic photothermal-enhanced chemodynamic therapy. Fe(III) ions in PDA@Fe nanoparticles can consume the GSH overexpressed in tumor microenvironment to avoid the potential center dot OH consumption, while the as-produced Fe(II) ions subsequently convert tumoral H2O2 into cytotoxic center dot OH radicals through the Fenton reaction. Notably, PDA@Fe nanoparticles demonstrate excellent near-infrared light absorption that results in superior photothermal conversion ability, which further boosts above-mentioned cascade catalysis to yield more center dot OH radicals for enhanced CDT. Taken together with T1-weighted magnetic resonance imaging (MRI) contrast enhancement (r1 = 8.13 mM- 1 s- 1) and