Coordination-driven robust antibacterial coatings using catechol-conjugated carboxymethyl chitosan

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Antimicrobial Coatings

Background:

• Bacterial contamination on solid surfaces poses significant risks, especially for medical devices.
• Developing effective, substrate-independent antibacterial coatings is crucial for infection control.

Purpose of the Study:

• To develop a simple and efficient antibacterial coating using catechol-conjugated carboxymethyl chitosan (CMC-DOPA).
• To evaluate the coating's performance on various substrates and its stability across different pH environments.

Main Methods:

• Synthesis of CMC-DOPA via aza-Michael reaction and acyl substitution with dopamine.
• Fabrication of multilayered films using spin-coating and coordination-driven crosslinking with Fe³⁺ ions.
• Assessment of bacterial adhesion reduction for E. coli and S. aureus on coated substrates.

Main Results:

• CMC-DOPA coatings significantly reduced bacterial adhesion by up to 99.8% for E. coli and 96.2% for S. aureus.
• The coating demonstrated robustness across acidic, physiological, and alkaline pH conditions, maintaining high antibacterial efficacy after 7 days.
• The coating was successfully applied to diverse substrates including silicon dioxide, titanium dioxide, and polyurethane.

Conclusions:

• The coordination-driven CMC-DOPA coating offers a versatile and effective solution for preventing bacterial contamination.
• This antibacterial coating technology holds promise for applications in medical devices and implants.
• The substrate-independent nature and pH stability make CMC-DOPA a highly adaptable antimicrobial surface treatment.