Self‐Driven Janus Ga/Mg Micromotors for Reducing Deep Bacterial Infection in the Treatment of Periodontitis

A self-propulsion Janus gallium (Ga)/magnesium (Mg) bimetallic micromotor is designed with favorable biocompatibility and antimicrobial properties as a therapeutic strategy for periodontitis. The Janus Ga/Mg micromotors are fabricated by microcontact printing technique to asymmetrically modify liquid metallic gallium onto magnesium microspheres. Hydrogen bubbles produced by the magnesium-water reaction can provide the driving performance of up to 31.03 µm s^-1 (pH 6.8), prompting the micromotor to actively breakthrough the biological barrier of saliva and gingival crevice fluid (GCF) into the bottom of periodontal pockets. In addition, the Janus Ga/Mg micromotors are effectively converted by degradation into the built-in antimicrobial ion Ga(III) to eliminate deep-seated Porphyromonas gingivalis (P.gingivalis), with bactericidal efficiencies of over 99.8%. The developed Janus Ga/Mg micromotors have demonstrated potent antimicrobial and anti-inflammatory activity both in vitro and in vivo studies. Crucially, it reduces alveolar bone resorption, demonstrating the superior efficacy of liquid metal gallium in treating periodontitis. Therefore, Ga/Mg bimetallic micromotors hold great promise to be an innovative and translational drug delivery system to treat periodontitis or other inflammation-related diseases in the near future.