Redox dual-responsive paclitaxel-doxorubicin heterodimeric prodrug self-delivery nanoaggregates for more effective breast cancer synergistic combination chemotherapy.

A single nanodrug delivery system for combined delivery of paclitaxel and doxorubicin that integrates high co-loading efficiency, synchronous co-delivery of combined drugs, controllable drug release, and maintains the drug combination at fixed synergistic ratios has been proven to be challenging. Here, we report a redox dual-responsive prodrug nanosystem consisting of a paclitaxel-doxorubicin heterodimeric prodrug with a thioether bond linkage to effectively co-deliver two therapeutic drugs. The heterodimeric prodrug could self-assemble into uniform nanoaggregates containing DSPE-PEG2K with a precise drug co-loading ratio in water, and possessed a high co-loading content. We demonstrated that this nanosystem provided strong synergistic effects in MCF-7 and 4 T1 cells. In vivo, this nanosystem results in a long blood circulation, high accumulation in the tumor, and significant inhibition of tumor growth in BALB/c mice bearing 4 T1 tumors. Such a simple, safe, and efficient heterodimeric prodrug nanosystem exhibits great potential for clinical translation in future combination chemotherapy treatments.