Nitric Oxide‐Actuated Titanium Dioxide Janus Nanoparticles for Enhanced Multimodal Disruption of Infectious Biofilms

Abstract

Sonodynamic therapy (SDT) is promising for combating deep‐seated infectious diseases by generating substantial reactive oxygen species (ROS) through the profound tissue penetration capabilities of ultrasound. However, the compact protective structures of bacterial biofilms present a formidable challenge, impeding ROS efficacy. Given that ROS have a limited diffusion range and current sonosensitizers struggle to infiltrate biofilms, complete eradication of pathogenic bacteria often remains unachieved. In this study, mesoporous titanium dioxide (TiO2) nanoparticles are engineered asymmetrically coated with a thin layer of Ag and loaded with L‐arginine (LA) to construct ultrasound‐propelled nanomotors. These Ag‐TiO2‐LA Janus nanoparticles demonstrate robust self‐propulsion upon ultrasonic activation, allowing for deeper penetration into biofilm matrices and enhancing localized biofilm disruption through improved SDT outcomes. Additionally, the incorporation of Ag not only broadens TiO2’s absorption spectrum but also confers photothermal capabilities upon NIR laser excitation at 808 nm. The Ag‐TiO2‐LA nanomotor amalgamates TiO2’s sonodynamic potential with Ag's photothermal properties, forging a versatile antimicrobial agent capable of efficient biofilm penetration and a synergistic antibacterial effect when subjected to dual NIR and ultrasound stimuli. This innovative, singularly‐structured nanoparticle stands out as an effective combatant against bacterial biofilms and accelerates the healing process of infected wounds, showcasing potential for multifaceted clinical applications.