Bubble-Propelled Janus Gallium/Zinc Micromotors for the Active Treatment of Bacterial Infections.

We report a bubble-propelled Janus gallium/zinc (Ga/Zn) micromotor with good biocompatibility and biodegradability for active target treatment of bacteria. The Janus Ga/Zn micromotors are fabricated by asymmetrically coating liquid metal Ga on Zn microparticles and display self-propulsion in simulated gastroenteric acid (pH 0.5) at a speed of up to 383 μm s , propelled by hydrogen bubbles generated by the zinc-acid reaction. This motion of Ga/Zn micromotors is enhanced by the Ga-Zn galvanic effect. The Ga cations produced from the degradation of Ga/Zn micromotors serve as a built-in antibiotic agent. The movement improves the diffusion of Ga and results in a significant increase of the antibacterial efficiency against H. pylori, compared with passive Ga microparticles. Such Ga/Zn micromotors combine the self-propulsion, good biocompatibility and biodegradability, and Ga-based antibacterial properties, providing a proof of concept for the active treatment of bacterial infections.