Anti-Biofouling Albumin Amyloid Coatings Enable Vancomycin-Mediated Bacterial Eradication on Medical Tubing

Abstract

Indwelling medical devices such as catheters and endotracheal tubes are major drivers of hospital-acquired morbidity and mortality due to bacterial colonization. The resulting healthcare-associated infections (HAIs) are further exacerbated by rising antimicrobial resistance, underscoring the urgent need for strategies that both prevent biofilm formation and reduce reliance on antibiotics. Polyvinyl chloride (PVC), a widely used material in medical tubing, is highly prone to bacterial attachment, making it a critical target for intervention. Here, we show that complete eradication of Staphylococcus aureus—both sessile on PVC and planktonic—can be achieved using a bovine serum albumin (BSA) amyloid-like coating in combination with vancomycin at a dose eight times lower than the MIC. While the amyloid film alone markedly reduces bacterial adhesion, the residual bacterial load still reaches infection-risk thresholds. This dual approach therefore not only prevents biofilm development but also significantly lowers antibiotic requirements, reducing the risk of resistance emergence and improving therapeutic safety. The coatings, deposited on PVC and on glass (as a model surface), were synthesized using dithiothreitol (DTT) as a reducing agent, as alternative to tris(2-carboxyethyl)phosphine (TCEP). Through optimization of the synthesis, the resulting films preserved their physicochemical and anti-biofouling properties while offering a simple, low-cost, and scalable approach. The coatings strongly adhere to both substrates, remain stable under aqueous and mechanical stress, and effectively suppress bacterial and mammalian cell adhesion without cytotoxicity. These properties are clinically relevant, reducing infection risk and mitigating tubing failure due to fibrous capsule formation, encasement, or crystallized biofilm-induced blockage. The demonstrated biocompatibility, robustness, and scalability of this coating platform underscore its translational potential as a clinically relevant strategy to mitigate HAIs, extend the functional lifetime of medical tubing, and alleviate the global burden of antimicrobial resistance.