PGP and neoplasm: The acidic environment of the endosome caused the degradation of PDA on the surface and exposed the black phosphorus nanosheets; under NIR irradiation, the black phosphorus nanosheets rapidly achieved photothermal conversion, increased the local temperature, and promoted the release of DOX and P-gp siRNA, inducing immunogenic death of tumor cells and inhibiting the expression of permeable glycoproteins.