Mucopenetrative Lipid–Polymer nanoparticles show Potent Anti-Inflammatory activity in a human Lung-on-Chip model

Airway mucus presents a significant barrier to inhaled drug delivery, particularly for nanoparticle-based interventions, with this barrier exacerbated in chronic respiratory diseases (CRDs) due to hyperviscous secretions and persistent inflammation. In this study, a dual-functional lipid-polymer hybrid nanoparticle was developed to combine rapid mucolysis with sustained anti-inflammatory activity, and its performance was evaluated using both conventional in vitro assays and a physiologically relevant lung-on-a-chip model. Dipalmitoylphosphatidylcholine (DPPC)-coated PLGA nanoparticles (hydrodynamic diameter 378.1 ± 23.0 nm; 58-61 wt% lipid; ζ ≈ +3 mV) encapsulated N-acetylcysteine (NAC) within the lipid shell for rapid release and all-trans retinoic acid (ATRA) within the core for sustained delivery. NAC exhibited a burst release of 44.2-52.5% within 6 h and significantly reduced the viscosity of cystic fibrosis-mimetic mucus, enabling a 26.5-fold higher penetration across a ∼ 0.6 mm mucus plug compared to NAC-free controls. The formulation was well tolerated by pulmonary epithelial and fibroblast cells and demonstrated high cellular uptake driven by the DPPC coating. To assess efficacy under physiologically relevant airway conditions, a human lung-on-a-chip model incorporating air-liquid interface, flow, and cyclic stretch was employed. In this model, repeated dosing of NAC + ATRA nanoparticles resulted in a 2.6-fold reduction in IL-6 and a 2.3-fold reduction in IL-8 levels compared to diseased controls at 72 h, outperforming NAC-free nanoparticles at early timepoints and maintaining suppression over 9 days. These findings demonstrate the therapeutic promise of dual-functional mucopenetrative nanoparticles and establish the utility of lung disease-on-chip platforms for evaluating inhaled nanotherapeutics under physiologically relevant conditions.