Immobilization of amphiphilic polycations by catechol functionality for antimicrobial coatings

Area of Science:

• Materials Science
• Polymer Chemistry
• Surface Chemistry
• Antimicrobial Technology

Background:

• Development of effective antimicrobial surfaces is crucial for preventing infections.
• Existing methods often involve complex procedures or lack long-term efficacy.
• Need for robust, easily prepared surfaces with tunable antimicrobial properties.

Purpose of the Study:

• To report a novel, simple dip-coating strategy for preparing antimicrobial polymer surfaces.
• To synthesize and characterize amphiphilic polycations with specific functional groups for surface immobilization and antimicrobial activity.
• To evaluate the antibacterial efficacy and surface properties of the developed coatings.

Main Methods:

• Synthesis of amphiphilic polycations via free-radical polymerization, incorporating dodecyl quaternary ammonium, methoxyethyl, and catechol groups.
• Preparation of polymer coatings on glass slides using a dip-coating procedure, followed by drying and heating.
• Assessment of antibacterial activity using dynamic contact assays against Escherichia coli, Staphylococcus aureus, and Acinetobacter baumannii.
• Surface characterization using Atomic Force Microscopy (AFM) and Sum-Frequency Generation (SFG) vibrational spectroscopy.

Main Results:

• The synthesized polycations formed stable, smooth antimicrobial coatings with potent bactericidal activity.
• Surfaces effectively prevented the accumulation of viable bacteria (E. coli, S. aureus, A. baumannii) for up to 96 hours.
• AFM and SFG analyses confirmed surface structure, demonstrating the localization of functional groups and the impact of hydrophobicity on surface roughness.
• Catechol groups promoted immobilization, preventing polymer leaching and enabling tunable amphiphilic balance for enhanced biocidal activity.

Conclusions:

• The dip-coating method provides a facile route to robust antimicrobial surfaces.
• Amphiphilic polycations with quaternary ammonium and catechol groups offer tunable properties and long-lasting antibacterial efficacy.
• This strategy holds promise for applications requiring infection control and prevention of microbial contamination.