Polymeric mixed micelles with triple stimuli-responsive characteristics and forster resonance energy transfer phenomenon for drug delivery system of chemotherapy and photodynamic therapy

In recent years, chemotherapy has been used in cancer treatment commonly. However, the hydrophobic property and non-selective apoptosis still limit its application. Recently, drug delivery systems (DDS) such as polymer micelles, liposomes, and dendrimers have been widely developed to improve the efficiency of chemotherapy. In this work, the amphiphilic polymer was used to encapsulate the Doxorubicin (DOX) through the self-assembly process to form the polymer micelles, and the drug release of DOX was controlled by the temperature-sensitive monomer (triethylene glycol methyl ether methacrylate, TEGMA) and redox-responsive group (disulfide bond, S-S). On the other hand, the intracellular internalization was improved by the photosensitizer drug (protoporphyrin IX, PpIX) through the photochemical internalization (PCI) process. The lower critical solution temperature (LCST) of micelles in this work was 37.6 degrees C, and the in-vitro test showed that 96% of DOX was released under acid conditions with the high level of redox agent. Finally, the chemotherapy was confirmed by the cytotoxicity assays and confocal laser scanning microscope (CLSM).