Bioinspired and eco-friendly high efficacy cinnamaldehyde antibacterial surfaces

Area of Science:

• Materials Science
• Biotechnology
• Chemistry

Background:

• Antimicrobial coatings are crucial for preventing infections.
• Essential oils offer natural antimicrobial properties but require effective delivery systems.
• Mussel-inspired and plant polyphenol coatings provide a versatile platform for incorporating active agents.

Purpose of the Study:

• To develop a single-step fabrication process for antimicrobial coatings using mussel-inspired and natural plant polyphenols.
• To evaluate the antibacterial efficacy of these coatings against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria.
• To assess the durability and reusability of the impregnated materials.

Main Methods:

• Incorporation of cinnamaldehyde (an antimicrobial essential oil component) into mussel-inspired (polydopamine, polyethyleneimine) and natural plant polyphenol (tannic acid) coatings.
• Fabrication of coatings on various substrates including polypropylene cloth, polytetrafluoroethylene membrane, and cotton cloth.
• Testing antibacterial activity using log10 reduction values against E. coli and S. aureus.
• Evaluating antibacterial efficacy over 17 recycle tests for impregnated non-woven polypropylene cloth.

Main Results:

• Polydopamine-cinnamaldehyde, polyethyleneimine-cinnamaldehyde, and tannic acid-cinnamaldehyde coatings demonstrated significant antibacterial activity.
• Both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus showed high susceptibility, with log10 Reduction = 8 for polydopamine- and tannic acid-based systems.
• Cinnamaldehyde impregnation into polypropylene cloth, PTFE membrane, and cotton cloth also resulted in high antibacterial activity (log10 Reduction = 8).
• Non-woven polypropylene cloth impregnated with cinnamaldehyde retained its antibacterial efficacy after 17 recycling tests.

Conclusions:

• A facile single-step method effectively created robust antimicrobial coatings.
• The developed coatings exhibit excellent broad-spectrum antibacterial activity.
• The materials demonstrate high durability and reusability, suggesting potential for long-term applications in preventing microbial contamination.