Precisely controlled and deeply penetrated micro-nano hybrid multifunctional motors with enhanced antibacterial activity against refractory biofilm infections.

The biofilm resistance of microorganisms has severe economic and environmental implications, especially the contamination of facilities associated with human life, including medical implants, air-conditioning systems, water supply systems, and food-processing equipment, resulting in the prevalence of infectious diseases. Once bacteria form biofilms, their antibiotic resistance can increase by 10–1,000-fold, posing a great challenge to the treatment of related diseases. In order to overcome the contamination of bacterial biofilm, destroying the biofilm's matrix so as to solve the penetration depth dilemma of antibacterial agents is the most effective way. Here, a magnetically controlled multifunctional micromotor was developed by using H 2 O 2 as the fuel and MnO 2 as the catalyst to treat bacterial biofilm infection. In the presence of H 2 O 2 , the as-prepared motors could be self-propelled by the generated oxygen microbubbles. Thereby, the remotely controlled motors could drill into the EPS of biofilm and disrupt them completely with the help of bubbles. Finally, the generated highly toxic •OH could efficiently kill the unprotected bacteria. This strategy combined the mechanical damage, highly toxic •OH, and precise magnetic guidance in one system, which could effectively eliminate biologically infectious fouling in microchannels within 10 min, possessing a wide range of practical application prospects especially in large scale and complex infection sites. [Display omitted] • Mechanical damage, highly toxic •OH, and precise magnetic guidance were integrated in one antimicrobial system. • H 2 O 2 was used as the fuel to trigger the high-speed movement of motor and serve as the source of high toxic •OH. • Enhanced antibacterial activities were obtained even for the treatment of drug-resistant bacteria MRSA. • The micro-nano hybrid multifunctional motors developed here are precisely controlled and deeply penetrated. • Motors have strong destructive ability for the treatment of large-scale biofilm EPS even at complex infection sites. [ABSTRACT FROM AUTHOR]