Environmental responsive drug carrier is a nanodrug delivery system able to change the structure or function of the tumor microenvironment, thus achieving targeted release of drugs and enhancing therapeutic effects. Environmental responsive drug carriers can be divided into different types, such as pH response, reduction responsiveness, enzyme response, temperature response, and light responsiveness, according to different stimuli. Tumor photochemotherapy combination therapy refers to the use of photosensitizer or photothermal agent and chemotherapy drugs combined to use, through the irradiation of light source, activate photosensitizer or photothermal agent to produce photodynamic effect or photothermal effect, thus killing tumor cells, and enhance the anti-tumor effect of chemotherapy drugs. Tumor photochemotherapy combination therapy has the advantages of high selectivity, low toxic side effects, and synergistic efficiency.

A pH responsive nanopedicine carrier was synthesized to load docetaxel (DTX), which was stable at pH=7.4 but rapidly released DTX under weakly acidic conditions (pH=5.5). The nanodrug carrier is combined with the photosensitizer copper zinc sulfide (CuS) to achieve efficient killing of breast cancer cells through near-infrared light (NIR) irradiation.