Prodrug-based combinational nanomedicine remodels lipid metabolism for reinforced ferroptosis and immune activation

Ferroptosis is a form of programmed cell death characterized by overwhelmed lipid oxidation, and it has emerged as a promising strategy for cancer therapy. Enhanced ferroptosis could overcome the limitations of conventional therapeutic modalities, particularly in difficult-to-treat tumors. In this study, we developed a dual-modality therapy in nanomedicine by combining paclitaxel (PTX) chemotherapy and pyropheophorbide-a (Ppa) phototherapy. Heparin (HP) was grafted with poly(N-(2'-hydroxy) propyl methacrylamide) (pHPMA) using reversible addition-fragmentation chain transfer polymerization to form HP-pHPMA (HH), which was utilized to deliver Ppa and PTX, yielding HP-pHPMA-Ppa (HH-Ppa) and HP-pHPMA-PTX (HH-PTX), respectively. The prodrug-based combinational nanomedicine (HH-PP) was formed by co-assembly of HH-PTX and HH-Ppa. It was found that HH-PP treatment significantly disrupted lipid metabolism in triple-negative breast cancer (TNBC) cells, induced extensive lipid oxidation, and promoted ferroptosis. In vivo, HH-PP intervention achieved a tumor growth inhibition rate of 86.63% and activated adaptive immunity with an elevated CD8⁺ cytotoxic T cell infiltration level. This combinational nanomedicine offers a promising platform for co-delivery of multiple therapeutic agents. It exerts a promising anti-tumor effect via enhanced ferroptosis and ferroptosis-induced immune activation by disrupting lipid metabolism in TNBC cancer cells.