A magnetic mucus-penetrating nanoagent boosting phlegm elimination for inhalation injury treatment

Abstract

Inhalation injuries arising from exposure to toxic gases or smoke in fires or industrial accidents pose grave risks and significant respiratory complications. The limited efficacy of current treatment strategies stems from challenges in delivering therapeutic agents across the mucus barrier to the damaged trachea and bronchus. This research explores the reparative potential and underlying mechanisms of sputum-penetrable magnetic nanoparticles (MNPs) coated with poly(N-isopropylacrylamide) (PNIPAM), combined with polyethylene glycol (PEG), and loaded with ambroxol hydrochloride (AH) (MNPs@PNIPAM-AH@PEG) as an innovative therapeutic approach for inhalation injuries. The PNIPAM coating, a thermo-responsive polymer, aims to enhance targeted drug release under an external stimulus. The PEG component is designed to mitigate hydrophobic repulsion and electrostatic forces, facilitating nanoagent penetration of the mucus barrier—an obstacle in inhalation injury treatment. PEG's hydrophilicity, combined with the magnetically attracted NPs, enables deep penetration through the mucus layer adhering to the mucus epithelium. Thermal effects break the outer thermal shell of MNPs, accelerating drug release, resolving sputum, and reducing inflammation. The results showed improved therapeutic impact by significantly reducing inflammation, enhancing mucociliary clearance, and promoting tissue repair. Moreover, the MNPs@PNIPAM-AH@PEG NPs showed good biocompatibility and biosafety both in vitro and in vivo. This research underscores the potential of MNPs@PNIPAM-AH@PEG NPs as a novel therapeutic strategy for inhalation injuries, paving the way for innovative treatments in emergency medicine and respiratory care.