Bioorthogonal Anchor‐and‐Lock of Probiotic Biofilms on Diverse Biomaterials to Combat Delayed Implant‐Associated Infection

Abstract

ABSTRACT Bacterial adhesion and biofilm formation on implants remain a leading cause of device failure, and delayed‐onset infections become refractory to antibiotics once mature biofilms form. Probiotic biofilms offer a promising alternative to conventional antimicrobial coatings, but clinical translation is hindered by the lack of a stable, substrate‐generalizable immobilization method. Here we presented a broadly applicable “anchor‐and‐lock” strategy that covalently tethered probiotic biofilms to diverse implants via bioorthogonal SPAAC reaction. A mussel‐inspired adhesive peptide functionalized with DBCO served as the surface anchor, while L. casei metabolically labeled with azide groups became the click‐ready lock. The resulting coatings formed uniformly on titanium, polyurethane, silicone rubber, and polypropylene, exhibiting long‐term stability. The biofilm operated through a dual‐phase antimicrobial mechanism, including an initial bactericidal phase (≥96% killing of S. aureus ) mediated by lactic acid and hydrogen peroxide release, followed by a sustained anti‐adhesive phase that prevented pathogen colonization. RNA‐sequencing revealed that the coating downregulated S. aureus adhesion‐associated genes while suppressing carbohydrate transport and metabolic pathways. In clinically relevant delayed‐infection models in bone and bladder, functionalized implants prevented infection, mitigated inflammation, and promoted tissue integration, effects absent on unmodified controls. This SPAAC‐mediated strategy offers a broad approach to mitigating implant‐associated infections.