Engineering Antibacterial and Lubricating Hydrogel Coatings via Substrate-Independent Catechol Chemistry-Catalyzed Interfacial Polymerization.

Hydrogel coatings are promising candidates for biomedical surface functionalization. However, developing multifunctional hydrogel coatings that simultaneously integrate robust lubrication, effective antibacterial capacity, and stable interfacial adhesion remains challenging. Herein, a simple, substrate-independent in situ interfacial polymerization strategy was proposed to construct multifunctional hydrogel coatings, which is driven by a catechol-Fe3+ dual self-catalytic system. The pre-coated polydopamine adhesive coating captures Fe3+ ions from monomer solution and forms redox pairs with intrinsic catechol moieties, which spontaneously triggers interfacial radical polymerization and enables precise control of hydrogel coating thickness. Zwitterionic monomer and aminoglycoside antibiotic are incorporated synergistically to endow the hydrogel coatings with significant hydrophilicity, excellent lubrication, and antibacterial performance. The obtained hydrogel coatings exhibit steady low friction coefficients over 12,000 reciprocating cycles and high antibacterial efficacy against Escherichia coli and Staphylococcus aureus. This versatile method is compatible with diverse engineering materials and medical catheters, establishing a practical pathway toward biomedical hydrogel coatings.