Abstract Background Multi-drug delivery system based on polymer carrier is emerging for alleviating dose-limiting toxicities of first-line cytotoxic anticancer drugs, such as doxorubicin (DOX) breast cancer chemotherapy. By co-loading the premium natural antioxidant salvianolic acid A (SAA) through colloidal self-assembly amphiphilic copolymer, we herein developed CPMSD, a complex polymeric mic...