ROS-responsive cyclodextrin nanoplatform for combined photodynamic therapy and chemotherapy of cancer

Cyclodextrin (CD) has special spatial structure and well biological safety, so it has been widely used for constructing CD-based nanoplatforms. Through functionalization, cyclodextrin can form various stimulus-response nanoplatforms, such as pH, temperature, redox, light and magnetic fields. In this study, we designed a highly sensitive reactive oxygen species (ROS)-responsive polymer PCP which encapsulated doxorubicin (DOX) and purpurin 18 (P18) to achieve the synergy of photodynamic and chemotherapy. The high content of reactive oxygen species (ROS) in the tumor microenvironment (TME) triggers the cleavage of the borate bond of MPEG-CD-PHB (PCP), thereby promoting the release of drugs. When irradiated with near-infrared laser, the photosensitizer P18 released by polymer micelles can produce reactive oxygen species to promote cell apoptosis. Compared with monotherapy, a series of experiments confirmed that our micelles had enhanced anti-cancer activity. This work was beneficial to the design of ROS-responsive materials and provides an effective strategy for the application of collaborative anti-tumor therapy.