A hydrogen-releasing polydopamine palladium hydride nanocoating protects airway mucosal injury induced by endotracheal tube cuff compression.

Endotracheal tube (ETT) cuff compression can induce severe airway mucosal injury through ischemia-reperfusion mechanisms, wherein oxidative stress plays a critical pathogenic role. Despite its clinical significance, effective protective strategies remain limited. Here, we developed a hydrogen-releasing nanocoating for ETT cuffs to mitigate airway injury. The coating was fabricated by integrating palladium hydride (PdH) nanoparticles into a polydopamine (PDA) matrix, creating a stable, uniform layer capable of sustained hydrogen release. Characterization confirmed successful PdH incorporation through UV-vis spectroscopy and X-ray diffraction analysis. In in vitro oxygen-glucose deprivation/reoxygenation (OGD/R) cell models using BEAS-2B human bronchial epithelial cells, the PDA-PdH coating (12.25 μg/mL) demonstrated selective scavenging of hydroxyl radicals and hydrogen peroxide while preserving beneficial superoxide species. The coating significantly reduced malondialdehyde and nitric oxide levels, enhanced superoxide dismutase activity, and protected mitochondrial integrity and cytoskeletal structure. Flow cytometry and TUNEL assays revealed marked reductions in intracellular reactive oxygen species and apoptosis rates. In in vivo evaluation using a rabbit tracheal intubation model with high cuff pressure (40 cmH2O) showed that PDA-PdH-coated ETTs effectively preserved tracheal mucosal integrity and attenuated inflammatory infiltration, as confirmed by histological examination and Western blot analysis of apoptosis-related proteins. Importantly, the coating exhibited acceptable short-term biocompatibility, with no observable cytotoxicity in vitro or gross histological organ damage within the 3-day observation window; however, comprehensive long-term biosafety evaluation remains to be conducted. These findings demonstrate that the PDA-PdH nanocoating represents a promising prophylactic strategy for preventing airway mucosal injury during endotracheal intubation.