Three-Dimensional, Bifunctional Microstructured Polymer Hydrogels Made from Polyzwitterions and Antimicrobial...

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Microbiology

Background:

• Biofilm-associated infections on medical devices pose a significant global health challenge.
• Current prevention strategies involve modifying biomaterial surfaces to impede initial biofilm formation stages.

Purpose of the Study:

• To develop and characterize bifunctional polymer surfaces combining chemical and topographical cues for inhibiting biofilm formation.
• To establish structure-property relationships for these surfaces by investigating topographical parameter effects on bioactivity.

Main Methods:

• Utilized microcontact printing (microCP), a soft lithography technique, to create structured polymer surfaces.
• Synthesized poly(oxanorbornene)-based synthetic mimics of antimicrobial peptides (SMAMPs) and a protein-repellent polysulfobetaine hydrogel.
• Fabricated bifunctional surfaces with varying spacings (1, 2, and 8.5 micrometers) and characterized them using advanced microscopy and spectroscopy techniques.

Main Results:

• Bifunctional surfaces with 1 and 2 micrometer spacing demonstrated 100% antimicrobial activity against Escherichia coli and Staphylococcus aureus.
• These surfaces also exhibited 100% fibrinogen repellency and were non-toxic to human gingival mucosal keratinocytes.
• Compromised antimicrobial activity and protein repellency were observed at 8.5 micrometer spacing, indicating an upper limit for effectiveness.

Conclusions:

• Bifunctional surfaces integrating chemical and topographical cues effectively inhibit bacterial adhesion, proliferation, and protein adsorption.
• Optimized surface topography, specifically 1-2 micrometer spacing, is crucial for achieving simultaneous broad-spectrum antimicrobial activity and protein repellency.
• The developed material presents a promising strategy for preventing biofilm-associated infections on medical devices.