Polydopamine-coated manganese/copper silicate nanoparticles for imaging-guided photothermal-augmented chemodynamic therapy

Amongst the various cancer treatment methods such as surgery, radiotherapy and chemotherapy, chemodynamic therapy (CDT) is considered as a tumor-specific technique that exploits the use of highly reactive oxygen species (ROS, such as hydroxyl radical •OH generated in Fenton-like catalytic reaction) to trigger cancer cell death. Herein, a strategy for the photothermal-augmented imaging-guided CDT is proposed. The manganese/copper ions doped silicate nanoparticles (MCMSN) are firstly prepared. Polydopamine is covered on the outside of the silicate nanoparticles to give the polydopamine-coated manganese/copper silicate nanoparticles (MCMSN@PDA). After entering the tumor site, the MCMSN@PDA decomposes and releases manganese and copper ions. The Cu(II) ion is reduced by GSH to Cu(I), which further reacts with H₂O₂ to generate toxic hydroxyl radicals (•OH). And manganese ion is employed as a magnetic resonance imaging reagent to realize the imaging-guided therapy. As a traditional photothermal material, polydopamine can generate heat under 808 nm laser irradiation, which causes tumor cell apoptosis. In addition, the generated heat can also enhance the CDT effect, and be used for photothermal imaging (PTI). The material achieves excellent anti-tumor therapeutic effect both in vitro and in vivo, which provides an effective paradigm for future design of multifunctional anticancer reagents.