Microfluidic programmable sequential-release nanoparticles enhancing Icariside II–cisplatin synergy via cholesterol modulation in NSCLC

Combination chemotherapy is a cornerstone of non-small cell lung cancer (NSCLC) treatment, with cisplatin (CDDP) serving as a frontline agent, but its clinical utility is severely compromised by resistance and systemic toxicity. Overcoming these limitations requires both effective CDDP-sensitizing agents and delivery systems capable of precisely controlling drug ratios and release sequence. Here, we identified Icariside II (IS), a bioactive flavonoid from Epimedium species, as a potent CDDP sensitizer. Synergy analyses confirmed that IS and CDDP exert strong cooperative effects at a 1:2 molar ratio. Mechanistically, IS downregulated 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR)/sterol regulatory element-binding transcription factor 2 (SREBF2), reduced intracellular cholesterol, and enhanced CDDP uptake and DNA damage, with IS pretreatment followed by CDDP producing the strongest antitumor effects. Guided by this mechanism, we engineered dual-drug polymer–lipid hybrid nanoparticles using a custom TrH microfluidic chip. Distinct from conventional methods, the TrH platform enabled programmable co-encapsulation with precise ratio control and intrinsic, stimulus-independent sequential release. Among the formulations, CDDP-IS@MNPs—programmed to release IS prior to CDDP—most effectively recapitulated the optimal sequence, inducing robust apoptosis in vitro, > 70% tumor growth inhibition in xenografts, prolonged survival in orthotopic models, and reduced cisplatin-induced hepatic and renal toxicity. Collectively, compared with our previous formulation-oriented work, this study achieves a substantial conceptual advance by integrating mechanistic insight with programmable microfluidic design, transforming the TrH chip into a preclinically validated platform for stepwise nanomedicine delivery, while also providing a promising therapeutic strategy to address the long-standing challenges of cisplatin-based combination chemotherapy.