A dual-nanozyme-loaded black phosphorus multifunctional therapeutic platform for combined photothermal/photodynamic/starvation cancer therapy.

The typical hypoxia of tumor microenvironments seriously affects the efficacy of starvation therapy (ST) and photodynamic therapy (PDT). Therefore, it is of great significance to prepare a multimodal combined therapy nanocomposite with the ability to relieve tumor hypoxia. It is an effective method to release oxygen into the tumor microenvironment using a nanoenzyme. In this work, two-dimensional black phosphorus nanosheets (BPNSs) were used as photothermal reagents and photosensitized agents due to the unique physical properties and also used as nano-carriers for the in situ reduction deposition of Au nanoparticles and fragmented MnO 2 coatings. Finally, polyethylene glycol was introduced to obtain the nanocomposite BP@Au@MnO 2 -PEG ( i.e. , AMGP). In the tumor microenvironment, MnO 2 can catalyze endogenous H 2 O 2 to produce oxygen, improving the effect of ST and PDT. H 2 O 2 generated via the catalytic oxidation of glucose by Au nanoparticles can continue to be used as the substrate catalyzed by MnO 2 . Meanwhile, black phosphorus nanosheets have excellent photothermal properties for photothermal treatment. The results of in vitro and in vivo experiments indicated that AMGP nanocomposites have good combined antitumor efficacies and biosafety.