Self-assembled multicomponent prodrugs with GSH/ROS site-responsiveness enable spatiotemporally controlled release for treating resistant NSCLC.

The resistance of non-small cell lung cancer (NSCLC) to Paclitaxel (PTX) stems from the enhanced drug efflux mediated by ATP-binding cassette (ABC) transporters and the upregulated PARP1-dependent DNA repair pathway. To address this challenge, the present study constructed a self-assembled nanoprodrug, PSOTNs, featuring covalent conjugation of three therapeutic agents. Structurally, PTX was functionalized with a disulfide bond to confer GSH-responsive release, whereas Olaparib (OLP) was tethered via a thioketal linker for ROS-triggered liberation, and tetramethylpyrazine (TMP) was hydrophobically modified to drive self-assembly and facilitated mitochondria-specific targeting under acidic conditions. The delicate PSOTNs exhibited high drug loading, favorable colloidal stability, and enhanced tumor accumulation via the EPR effect. Upon cellular internalization, the elevated GSH level prompted rapid release of PTX, effectively inhibiting microtubule dynamics. Concurrently, TMP-mediated mitochondrial enrichment and the subsequent ROS-triggered cleavage released OLP along with cinnamaldehyde, which synergistically amplified oxidative stress, induced mitochondrial dysfunction, and suppressed P-glycoprotein-mediated drug efflux. In vitro assays demonstrated that PSOTNs significantly enhanced drug accumulation, induced DNA damage, provoked G2/M cell cycle arrest, and promoted apoptosis, outperforming both individual agents and the non-responsive control. Furthermore, PSOTNs revealed potent tumor growth inhibition in A549/Tax xenograft models, prolonged systemic circulation, and excellent biocompatibility. In summary, PSOTNs represent a novel nanotherapeutic strategy that overcomes PTX resistance through a triple synergistic mechanism of "microtubule disruption-DNA repair inhibition-mitochondrial function intervention," offering a promising paradigm for the treatment of drug-resistant malignancies.