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Due to the emergence of wide-spread infectious diseases, there is a heightened need for antimicrobial and/or antifouling coatings that can be used to prevent infection and transmission in a variety of applications, ranging from healthcare devices to public facilities. While antimicrobial coatings kill pathogenic bacteria upon contact with the surface, the antimicrobial function alone often lacks long-term effectiveness due to the accumulation of dead cells and their debris on the surface, thus reducing the performance of the coating over time. Therefore, it is desirable to develop coatings with the dual functions of antimicrobial efficacy and fouling resistance, in which antifouling coatings provide the added benefit of preventing the adhesion of dead cells and debris. Leveraging the outstanding antifouling properties of zwitterionic coatings, we synthesized copolymers with this antimicrobial-antifouling dual function by immobilizing lysozyme, a common antimicrobial enzyme, to the surface of a pyridinium-based zwitterionic copolymer. Specifically, poly(4-vinylpyridine- co -pentaflurophenyl methacrylate- co -divinyl benzene) [P(4VP-PFPMA-DVB)] thin films were synthesized by an all-dry vapor deposition technique, initiated Chemical Vapor Deposition, and derivatized using 1,3-propane sultone to obtain sulfobetaine moieties. Lysozyme, known to hydrolyze polysaccharides in the cell wall of Gram-positive bacteria, was immobilized by forming amide bonds with the copolymer coating via nucleophilic substitution of the pentafluorophenyl group. The antifouling and antibacterial performance of the novel lysozyme-zwitterionic coating was tested against Gram-positive Bacillus subtilis and Gram-negative Pseudomonas aeruginosa . A reduction in surface adhesion of 87% was achieved for P. aeruginosa , and of 75% for B. subtilis , when compared to a common poly(vinyl chloride) surface. The lysozyme-zwitterionic coating also deactivated 67% of surface-attached Gram-positive bacteria, B. subtilis . This novel dual-function material can produce anti -infection surfaces for medical devices and surgical tools, personal care products, and surfaces in public facilities.
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Dynamic Antimicrobial Poly(disulfide) Coatings Exfoliate Biofilms On Demand Via Triggered Depolymerization
Abstract Bacterial biofilms are notoriously problematic in applications ranging from biomedical implants to ship hulls. Cationic, amphiphilic antibacterial surface coatings delay the onset of biofilm formation by killing microbes on contact, but they lose effectiveness over time due to non‐specific binding of biomass and biofilm formation. Harsh treatment methods are required to forcibly expel the biomass and regenerate a clean surface. Here, a simple, dynamically reversible method of polymer surface coating that enables both chemical killing on contact, and on‐demand mechanical delamination of surface‐bound biofilms, by triggered depolymerization of the underlying antimicrobial coating layer, is developed. Antimicrobial polymer derivatives based on α‐lipoic acid (LA) undergo dynamic and reversible polymerization into polydisulfides functionalized with biocidal quaternary ammonium salt groups. These coatings kill >99.9% ofStaphylococcus aureuscells, repeatedly for 15 cycles without loss of activity, for moderate microbial challenges (≈105colony‐forming units (CFU) mL−1, 1 h), but they ultimately foul under intense challenges (≈107CFU mL−1, 5 days). The attached biofilms are then exfoliated from the polymer surface by UV‐triggered degradation in an aqueous solution at neutral pH. This work provides a simple strategy for antimicrobial coatings that can kill bacteria on contact for extended timescales, followed by triggered biofilm removal under mild conditions.
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- PAR ID:
- 10641123
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Healthcare Materials
- Volume:
- 13
- Issue:
- 11
- ISSN:
- 2192-2640
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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