Acid‐sensitive reactive oxygen species triggered dual‐drug delivery systems for chemo‐photodynamic therapy to overcome multidrug resistance

In clinical treatment, multidrug resistance (MDR) is one of the major obstacles resulting in the failure of chemotherapy. It is still a challenge to overcome MDR. Herein, we fabricated intelligent dextran‐based dual‐drug delivery systems histidine modified dextran conjugated doxorubicin/zinc porphyrin/paclitaxel (DHTD/Zn‐TPP/PTX) via supramolecular metallo‐coordination for synergistic chemo‐photodynamic therapy to overcome cancer drug resistance. In this designed DHTD/Zn‐TPP/PTX, one anticancer drug (doxorubicin, DOX) was conjugated on the dextran backbone through a reactive oxygen species sensitive linker and the other drug PTX was encapsulated into the acid responsive supramolecular micelles formed by the photosensitizer Zn‐TPP and histidine grafted on dextran. DHTD/Zn‐TPP/PTX with excellent stability could be effectively internalized by tumour cells. In the acidic tumour environment, the loaded PTX and Zn‐TPP as photosensitizer could be released; moreover, when irradiated with light the conjugated DOX could be specifically released because the linker broke. As the obtained data indicate, DHTD/Zn‐TPP/PTX exhibited not only an enhanced anticancer therapeutic effect but also significant growth inhibition for drug‐resistant MCF‐7/ADR cells to reverse MDR, having great potential for synergistic treatments of cancer to overcome MDR. © 2020 Society of Chemical Industry