Spatiotemporally programmed hybrid nano-prodrugs orchestrate multidimensionally synergistic cascade lethality in NSCLC

Rationale: Non-small cell lung cancer (NSCLC) develops a high GSH/GPX4 antioxidant phenotype under persistent oxidative pressure, which suppresses membrane lipid peroxidation and ferroptosis, constituting a core mechanism underlying chemotherapy resistance and suboptimal therapeutic efficacy. Breaking this resistance barrier demands not simply attacking the tumor but disarming the antioxidant defense to intensify oxidative damage and awaken durable antitumor immunity.

Methods: A self-assembled nano-prodrug, E-R@ISSL, was engineered by co-assembling a carbamate-linked RGD-modified etoposide (ETP) prodrug and a disulfide-bonded indole derivative conjugated to linoleic acid (LA) at an optimal 1:2 molar ratio. The system thus possesses dual αvβ5/mitochondria targeting with CES2/GSH cascade-responsive drug release. Antitumor activity and mechanisms were evaluated in vitro and in both subcutaneous and orthotopic NSCLC mouse models.

Results: E-R@ISSL exhibited efficient αvβ5-mediated internalization and mitochondria-targeted delivery. Upon sequential CES2/GSH-triggered disassembly, E-R@ISSL co-released ETP and LA, reduced the available intracellular GSH pool, and functionally dampened the GSH-dependent GPX4 antioxidant defense. ETP induced DNA double-strand breaks and elevated reactive oxygen species (ROS), while LA expanded the oxidizable lipid pool, synergistically driving lipid peroxidation and ferroptosis. Concurrently, the system activated immunogenic cell death (ICD), promoting dendritic cell maturation and enhancing CD8+ T cell infiltration. In orthotopic NSCLC models, E-R@ISSL significantly suppressed tumor progression, prolonged survival, and demonstrated a favorable safety profile with reduced systemic toxicity compared with free ETP.

Conclusions: Together, these findings demonstrate that E-R@ISSL achieved coordinated DNA damage, ferroptosis, and ICD induction through its dual-targeted and sequentially activated co-delivery of ETP and LA, concurrently dismantling the GSH/GPX4 antioxidant defense and intensifying oxidative injury. This nano-prodrug thus represents a viable strategy for overcoming treatment resistance and extending durable antitumor responses in NSCLC.