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.