A pH-responsive AIE nanoprobe as a drug delivery system for bioimaging and cancer therapy

To construct a smart drug delivery system for simultaneous cellular imaging and cancer therapy, a pH-responsive amphiphilic polymer (MPEG-hyd-TPE) with aggregation-induced emission (AIE) character was designed and successfully synthesized. Polymeric micelles self-assembled from MPEG-hyd-TPE exhibited a significant AIE effect in an aqueous solution with excellent biocompatibility; thus, it can be used for potential bioimaging applications. Moreover, the drug-loaded micelles showed typical pH-regulated drug release behavior. DOX was released more rapidly after the drug-loaded micelles were internalized into cancer cells due to the cleavage of the hydrazone bond under acidic endosomal/lysosomal conditions. In addition, in vitro results demonstrated that the drug-loaded micelles exhibited dose-dependent cytotoxicity to HeLa cells.