(28b) A Cascade Nanozyme with Antimicrobial Effects against Otitis Media Pathogen

Otitis media (OM) is one of the most common reasons for pediatric antibiotic prescriptions and nontypeable Haemophilus influenzae (NTHi) is the pathogen opportunistically invading the middle ear space and casuing OM. Currently, the NTHi forms biofilm that resists conventional antimicrobials and immune clearance exhibiting a major obstacle to effective medical treatment globally. Novel treatments that are effective against the growth of NTHi and its biofilm are therefore urgently required. To address that challenge, we designed a cascade nanozyme that could generate antiseptic from non-Reactive Oxygen Species (ROS), which in turn completely eradicated the growth of NTHi. The cascade nanozyme composed of vanadium pentoxide nanowires (V₂O₅ NWs) with protection layer of dopamine (DPA) and gold nanoparticles (AuNPs) on the surface, possessing intrinsic glucose oxidase (GOx)-like activity and haloperoxidase (HPO)-mimicking activity. DPA was used to ensure adjacency of V₂O₅ NWs and AuNPs, a key to enabling their cascade catalytic activities, to protect V₂O₅ NWs from the strongly reducing synthesis environment (used for AuNPs), and to protect AuNPs from aggreation. The cascade nanozyme demonstrated strong antimicrobial efficacy against the growth of NTHi and potential of inhibiting bioiflm formation by changing biofilm morphology with relatively low toxicity to mammalian cells.