A small-molecule self-assembled nano-prodrug for enhanced therapy of cancer stem cell-enriched pancreatic ductal adenocarcinoma

Cancer stem cells (CSCs) play a pivotal role in the initiation, metastasis, and recurrence of pancreatic tumors, significantly contributing to drug resistance and reducing the efficacy of traditional chemotherapy. To address these challenges, we developed an amphipathic self-assembled nano-prodrug to co-deliver all-trans retinoic acid (ATRA), gemcitabine (GEM), and ferroptosis inducer (RSL3) for the combined therapy of pancreatic ductal adenocarcinoma (PDAC). The amphipathic prodrug (ATRA-GEM) was synthesized by conjugating ATRA and GEM via an ester bond, enabling good self-assembly and the simultaneous loading of the ferroptosis inducer RSL3. In tumor microenvironment, this combinational nano-prodrug disassembles in response to high level of esterase, triggering the controlled release of ATRA, RSL3, and GEM. The released drugs exhibited a combinational therapeutic effect in vitro by combining apoptosis, ferroptosis, and differentiation therapy. For in vivo application, the nano-prodrug was modified with DSPE-PEG-RGD to enhance tumor-targeting capability and prolong blood circulation. This nano-prodrug demonstrated significant anti-PDAC efficacy and good biosafety in both cell-derived xenograft and patient-derived xenograft models. STATEMENT OF SIGNIFICANCE: Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest cancers due to drug resistance and tumor relapse driven by cancer stem cells (CSCs). Here, we report an amphipathic self-assembled nano-prodrug that simultaneously delivers a differentiation agent (ATRA), a chemotherapeutic (gemcitabine), and a ferroptosis inducer (RSL3). Unlike existing therapies that target only one tumor population, this strategy integrates CSC differentiation, ferroptosis-induced cell death, and chemotherapy into a single platform, enabling coordinated elimination of both CSCs and bulk tumor cells. This nano-prodrug also features high drug-loading capacity and tumor-targeted, stimulus-responsive release. This work provides a new strategy for overcoming resistance and achieving more durable therapeutic outcomes in PDAC, with broad implications for treating other refractory cancers.