Abstract: Bacterial biofilms pose a significant challenge in healthcare, particularly due to their role in persistent infections associated with medical implants and devices. Existing therapeutic strategies often fail to eradicate mature biofilms, highlighting the urgent need for preventive surface engineering techniques capable of effectively inhibiting biofilm formation. This study presents a dual-target antibiofilm coating developed through coordination-driven assembly of tannic acid with Ga³⁺ and Cu²⁺ ions. The coating exploits the intrinsic adhesive properties of metal-phenolic networks, enabling substrate-independent deposition via simple aqueous processing. It remains stable under physiological conditions while releasing therapeutic ions in response to the acidic microenvironment created by biofilm formation. Cu²⁺ ions induce rapid bactericidal activity through membrane disruption, while Ga³⁺ ions target bacterial iron metabolism via a “Trojan horse” mechanism, circumventing conventional antimicrobial resistance pathways. The synergistic action of these ions ensures sustained antibiofilm efficacy for three days against Pseudomonas aeruginosa and Staphylococcus aureus, two clinically significant pathogens. Furthermore, the coating exhibits excellent cytocompatibility with mammalian cells and strong environmental stability, meeting key requirements for practical application. This dual-target approach establishes a new paradigm for broad-spectrum, long-term biofilm prevention and provides a scalable solution for infection-resistant medical device coatings.

Key words: Biofilm, Antibiofilm coatings, Metal-phenolic networks, Iron metabolism