Ultrasound Activatable Microbombs via Co-Loading CaO2/Perfluorohexane for Cascade Catalytic Biofilm Disruption and Caries Prevention

Biofilms are the chief culprits of most intractable infections and pose great threat to human health. Developing effective strategies to sweep away the detrimental microbe and stubborn biofilm still remains a challenge. Here, an ultrasound (US) activated microbomb is constructed by encapsulating perfluorohexane (PFH) and iron-tannin modified calcium peroxide (CaO2-TA-Fe) in poly(lactide-co-glycolide) (PLGA) vesicles as the reactive oxygen species (ROS) generating reactors for dental biofilm elimination. Upon the US irradiation by ultrasonic toothbrush, the swiftly vaporized PFH can not only promptly explode the PLGA shell to facilitate the generation of H2O2 from CaO2, but also blast the tight biofilm for effective delivery of the lethal hydroxyl free radicals (center dot OH) caused by degradative Fe3+ from iron-tannin network, thereby proceeding cascade catalysis eradication of biofilm. As a proof-of-concept, this study demonstrates the proposed synergetic paradigm that integrates the US-triggered explosion with ROS-induced sterilization for stubborn biofilm elimination, and is a promising tactic for the costly and prevalent caries prevention as well as the biofilm-associated diseases treatments.