An intelligent tumor microenvironment responsive nanotheranostic agent for T1/T2 dual-modal magnetic resonance...

Photothermal therapy (PTT), as a promising antineoplastic therapeutic strategy, has been harnessed to restrain tumor growth through near-infrared (NIR) irradiation mediated thermal ablation. Nevertheless, its biological applications are hampered by thermal diffusion and up-regulated heat shock proteins (HSPs). Herein, a versatile nanotheranostic agent is developed via integrating Zn_0.2Fe_2.8O₄ nanoparticles (NPs), polydopamine (PDA), and MnO₂ NPs for T1/T2 dual-modal magnetic resonance (MR) imaging-guided and self-augmented PTT. The as-designed Zn_0.2Fe_2.8O₄@PDA@MnO₂ NPs adequately serve as a PTT agent to realize effective photothermal conversion and obtain local hyperthermia. Additionally, the Zn_0.2Fe_2.8O₄@PDA@MnO₂ NPs can significantly consume overexpressed glutathione (GSH) and generate Mn²⁺ in the tumor microenvironment (TME), thus destroying redox homeostasis and catalytically generating hydroxyl radicals (˙OH) for HSP suppression and PTT enhancement. Meanwhile, Mn²⁺ and Zn_0.2Fe_2.8O₄ NPs significantly strengthen T1- and T2-weighted MR contrast for tumor imaging and PTT guidance. Hence, this study offers proof of concept for self-augmented PTT and T1/T2 dual-modal MR imaging for tumor elimination.