PDA-Based Nanoplatform with High Ligustilide Loading for Simultaneous Elimination of Breast Cancer Cells and Stem Cells Via BAX/BCL-2/Caspase-3 Pathway Activation.

Breast cancer (BC) remains the most prevalent and deadly malignancy among women worldwide. While photothermal therapy (PTT) and chemodynamic therapy (CDT) offer tumor-specific and minimally invasive advantages, their standalone efficacy is limited. Ligustilide (LIG) can exert antitumor effects by generating •O2-, but its bioavailability is poor, thus necessitating improved delivery strategies. Here, we reported a multifunctional nanoplatform (FeD@LIG) integrating PTT, CDT, and chemotherapy for the simultaneous elimination of breast cancer stem cells (BCSCs) and non-BCSCs. FeD@LIG was synthesized via one-step oxidative polymerization of dopamine, co-loading Fe3+ and LIG. The nanospheres exhibited excellent photothermal conversion efficiency (52.8%) and pH/GSH-responsive drug release. Upon near-infrared (NIR) irradiation, FeD@LIG triggered ROS generation via Fenton-like reactions and elevated local temperature, leading to enhanced oxidative stress, apoptosis, and LIG release. In vitro, FeD@LIG reduced cell viabilities of MCF-7 and MDA-MB-231 cells to 12.5 and 7.9%, respectively, and significantly inhibited BCSCs' self-renewal. In vivo, FeD@LIG achieved a tumor inhibition rate of 92.8% with minimal toxicity. Mechanistic studies revealed activation of the BAX/BCL-2/Caspase-3 pathway and suppression of Hedgehog signaling. Overall, FeD@LIG represents a promising nanotherapeutic strategy for overcoming drug resistance and recurrence by inhibiting both BCSCs and non-BCSCs through multimodal synergistic therapy.