Hybrid membrane vesicle-enabled sonodynamic therapy using ciprofloxacin for treating biofilm-associated infections.

Biofilm-associated infections on indwelling medical devices pose significant clinical challenges due to antibiotic resistance and poor drug penetration. Sonodynamic therapy (SDT) is a promising strategy utilizing ultrasound to activate sonosensitizers for generating reactive oxygen species (ROS). However, the lack of safe and effective sonosensitizers and bacterial-targeting delivery systems limits its application in treating biofilm infection. To address these limitations, we developed antibiotic ciprofloxacin-loaded hybrid membrane vesicles (CIP@HMVs), where ciprofloxacin acts as a safe sonosensitizer and HMVs serve as a detoxified bacterial-targeted delivery system. HMVs were engineered by fusing Pseudomonas aeruginosa-derived outer membrane vesicles (PAEVs) with macrophage membrane vesicles (MMVs), creating a dual-functional nanoplatform with homotypic bacteria-targeting and detoxification capabilities. CIP@HMVs exploited ciprofloxacin's sonosensitizer properties to generate singlet oxygen (1O2) under ultrasound, while HMVs enhanced bacterial uptake in P. aeruginosa. This enabled synergistic bactericidal effects against planktonic bacteria via membrane disruption and intracellular ROS burst, achieving a 5.7-log bacterial reduction in catheter biofilms in vitro. Crucially, HMVs neutralized PAEVs' LPS toxicity in vitro and demonstrated negligible systemic toxicity in vivo. In a murine catheter-infection model, CIP@HMVs under ultrasound achieved 99.8% bacterial eradication and reduced inflammation. This bacterial-targeting sonodynamic platform provides a transformative strategy for treating device-associated biofilm infections with high efficacy and biosafety.