Co-delivery of dihydroartemisinin and docetaxel in pH-sensitive nanoparticles for treating metastatic breast cancer via the NF-κB/MMP-2 signal pathway

Metastasis is a major barrier in cancer chemotherapy. Prolonged circulation and rapid, specific intracellular drug release are two main goals in the development of nanoscale drug delivery systems to treat metastatic breast cancer. In this study, we investigated the anti-metastasis effect of docetaxel (DTX) in combination with dihydroartemisinin (DHA) in metastatic breast cancer 4T1 cells. We synthesized a pH-sensitive material 4-arm-PEG-DTX with a hydrazone bond and used it to construct nanoparticles that co-deliver DTX and DHA (D/D NPs). The D/D NPs had a mean size of 142.5 nm and approximately neutral zeta potential. The pH-sensitive nanoparticles allowed acid-triggered drug release at the tumor site, showing excellent cytotoxicity (IC50 = 7.0 μg mL(−1)), cell cycle arrest and suppression of cell migration and invasion. The mechanisms underlying the anti-metastasis effect of the D/D NPs involved downregulation of the expression of p-AKT, NF-κB and MMP-2. Therefore, D/D NPs represent a new nanoscale drug delivery system for treating metastatic breast cancer, responding to the acidic tumor microenvironment to release the chemotherapeutic drugs.