A robust adhesive microneedle for oral infections therapy via synergistic antibacterial and neutrophil-macrophage axis immunomodulation

Oral infectious diseases are challenging to treat, as conventional therapies struggle to maintain effective drug levels and simultaneously address both Infection and immune dysregulation. To address this, we developed a mussel-inspired microneedle patch (PCA@FeCO MN) by incorporating Fe₃(CO)₁₂ into a caffeic acid-grafted polyvinyl alcohol network. This design overcomes existing barriers through a dual-adhesion mechanism: a catechol-metal coordination network for strong chemical bonding and an optimized taper geometry for mechanical interlocking in wet oral tissues. Upon near-infrared irradiation, PCA@FeCO MN activates a photothermal-ferroptosis-gas therapy cascade, synergistically eradicating pathogens. Crucially, this strategy also disrupts the inflammation cycle by steering neutrophils toward function activation, timely Apoptosis and boosting macrophage efferocytosis. In both rat and beagle dog models of oral infections, PCA@FeCO MN achieved robust tissue adhesion, highly efficient synergistic Antibacterial activity, and precise immunomodulation, demonstrating its promising therapeutic potential for future clinical translation.