NIR-II-responsive AuNRs@SiO-RB@MnO nanotheranostic for multimodal imaging-guided CDT/PTT synergistic cancer therapy.

Specific tumor-responsive capabilities and efficient synergistic therapeutic performance are the keys to effective tumor treatment. Herein, AuNRs@SiO-RB@MnO was developed as a new type of tumor-responsive nanotheranostic for multimodal imaging and synergistic chemodynamic/photothermal therapy. In AuNRs@SiO-RB@MnO, the SiO layer wraps the AuNRs, providing light absorption in the second near-infrared (NIR-II) region. The SiO layer also adsorbs the MnO nanosheets, which have Fenton-like activity, resulting in a fluorescent sensing platform based on the fluorescence quenching properties of MnO for rhodamine B dye. The fluorescence can be recovered by the consumption of MnO by glutathione, which simultaneously produces Mn in the tumor region. The recovery of fluorescence reflects the consumption of glutathione and the increase in Mn, which produces hydroxyl radicals Fenton-like reaction in the tumor microenvironment to realize chemodynamic therapy. Meanwhile, the AuNRs are a good photothermal reagent that can effectively absorb NIR-II light and convert it into heat energy to kill tumor cells photothermal therapy. The NIR-II absorption performance of the AuNRs provides good photoacoustic imaging and deep photothermal performance, which is favorable for efficient NIR-II photoacoustic imaging-guided photothermal therapy. As a result, the AuNRs@SiO-RB@MnO nanotheranostic exhibits outstanding imaging and synergistic chemodynamic/photothermal therapeutic performance for tumor imaging and treatment.