Neutrophil membrane-encapsulated nanosonosensitizer with ultrasound-reinforced ferroptosis in Pseudomonas aeruginosa pneumonia

Pneumonia caused by Pseudomonas aeruginosa (P. aeruginosa) infection remains a formidable clinical challenge due to persistent biofilm formation and intrinsic antibiotic resistance, exacerbated by bacterial iron homeostasis that stabilizes biofilm architecture and neutralizes oxidative stress. Herein, we present Fe/TNT@NM, a biomimetic nanosonosensitizer activated by ultrasound (US) to dismantle biofilms through dual extracellular-intracellular mechanisms. The nanosonosensitizer features an iron-doped titanate nanotube (Fe/TNT) core encapsulated within a neutrophil membrane (NM). Under US irradiation, Fe/TNT@NM generates sonodynamic reactive oxygen species (ROS) extracellularly and enhances Fe³⁺ release. These ions catalyze the Fenton reaction extracellularly to amplify chemodynamic effects and disrupt intracellular iron homeostasis, triggering bacterial ferroptosis. The NM coating enables immune evasion and biofilm-targeted delivery. This ultrasound-reinforced ferroptosis strategy synchronizes extracellular ROS storms with intracellular iron dyshomeostasis, achieving dual-action biofilm dismantling and eradication of drug-resistant P. aeruginosa. In a murine pneumonia model, Fe/TNT@NM suppresses biofilms and mitigates pulmonary injury. By converging biomimetic targeting, sonodynamic-chemodynamic cascades, and ultrasound-augmented ferroptosis, this nanosonosensitizer presents a paradigm-shifting approach to combat refractory biofilm infections and antibiotic resistance.