Targeting stem-property and vasculogenic mimicry for sensitizing paclitaxel therapy of triple-negative breast cancer by biomimetic codelivery.

Triple-negative breast cancer (TNBC) is aggressive, with high recurrence rates and poor prognosis. Paclitaxel (PTX) remains a key chemotherapeutic agent for TNBC, but its efficacy diminishes due to the emergence of drug resistance, largely driven by cancer stem-like cells (CSCs), vasculogenic mimicry (VM) formation and tumor immunosuppressive microenvironment (TIME). Pyruvate kinase M2 (PKM2) is highly expressed in TNBC, and is a potential target for TNBC treatment. In this study, we developed a biomimetic codelivery system using albumin nanoparticles (termed S/P NP) to co-encapsulate PTX and shikonin (SHK), a natural inhibitor of PKM2. By inhibiting PKM2, SHK suppressed -Catenin signaling, thereby reversing CSC stemness and preventing VM formation. The S/P NP system exhibited tumor-targeting delivery effect and significantly inhibited TNBC growth and lung metastasis. Mechanistically, the treatment reversed epithelial-mesenchymal transition (EMT) and stem-like properties of TNBC cells, suppressed VM formation, and remodeled the TIME. It reduced immunosuppressive cells (M2 macrophages, MDSCs) while promoting anti-tumor immunity (M1 macrophages, dendritic cells, cytotoxic T cells, and memory T cells). This dual-action strategy holds promise for improving TNBC therapy by targeting CSCs, VM, and the immune microenvironment, and for overcoming PTX resistance and reducing metastasis.