Antibacterial performance of polydopamine-modified polymer surfaces containing passive and active components

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Infectious Disease Research

Background:

• Device-related nosocomial infections pose a significant clinical challenge, increasing costs and patient morbidity.
• Existing antibacterial strategies for medical devices often lack comprehensive antifouling capabilities.
• Polydopamine (PDA) coatings offer a versatile platform for surface functionalization.

Purpose of the Study:

• To develop a novel coating strategy for medical devices with combined antifouling and antimicrobial properties.
• To utilize polydopamine's ability to immobilize polymers and form metal nanoparticles.
• To create a robust and adaptable surface modification for clinical applications.

Main Methods:

• Polydopamine thin films (4 nm) were deposited on polycarbonate substrates via an aqueous dip-coating method.
• Antifouling polyethylene glycol (PEG) brushes were grafted onto PDA-coated surfaces.
• Silver nanoparticles (AgNPs) were formed in situ on the PDA-coated substrates using silver nitrate solutions.

Main Results:

• Surface analyses confirmed successful PEG grafting and spontaneous AgNP formation.
• Sustained silver release over 7 days was observed, with tunable kinetics via PDA overlayers.
• The developed coating demonstrated dual fouling resistance (from PEG) and antibacterial efficacy (from AgNPs) against Gram-negative and Gram-positive bacteria.
• Compared to commercial silver-only coatings, this method inhibited bacterial attachment more effectively.

Conclusions:

• The polydopamine-based strategy enables simultaneous antifouling and antimicrobial surface functionalization.
• This approach offers a promising solution for reducing device-related infections and improving clinical device performance.
• The versatility of polydopamine suggests broad applicability across various substrate materials.