Long-term moxifloxacin release from a chitosan-based antibacterial coating on polyethylene for biomedical...

Area of Science:

• Biomaterials Engineering
• Infectious Disease Research
• Polymer Science

Background:

• Medical-grade polyethylene (PE) surfaces are prone to bacterial colonization and biofilm formation, contributing to hospital-associated infections (HAIs).
• Current antibacterial coatings often suffer from limited efficacy duration and poor substrate adhesion.
• Natural polymers offer an alternative to systemic antibiotics for preventing biofilm formation.

Purpose of the Study:

• To develop a robust antibacterial coating for polyethylene (PE) medical devices with prolonged antimicrobial activity and enhanced adhesion.
• To investigate a wet-chemistry functionalization strategy involving polydopamine for improved coating performance.
• To evaluate the adhesion, drug release kinetics, and antibacterial efficacy of the developed coating.

Main Methods:

• Polyethylene surfaces were functionalized using piranha solution and polydopamine deposition.
• Moxifloxacin-loaded chitosan formulations were applied as coatings.
• Surface characterization was performed using XPS to confirm chemical modifications.
• Coating adhesion was tested in phosphate-buffered saline (PBS) over 35 days.
• Antibiotic release profiles and antibacterial activity against *S. aureus* and *E. coli* were assessed over 160 days.

Main Results:

• The functionalization process enhanced surface roughness and hydrophilicity, facilitating uniform polymer coating deposition.
• XPS analysis confirmed successful surface modification with carbon oxidate species, polydopamine, and chitosan.
• The coating demonstrated stable adhesion to the PE substrate for at least 35 days.
• Moxifloxacin exhibited an initial burst release followed by sustained release over the study period.
• The antibacterial coating effectively inhibited the growth of *S. aureus* and *E. coli* for up to 160 days.

Conclusions:

• A wet-chemistry functionalization approach, including polydopamine activation, creates a strongly adhered, long-lasting antibacterial chitosan-based coating on PE.
• This strategy provides sustained moxifloxacin release and effective inhibition of clinically relevant pathogens.
• The developed coating represents a promising approach to reduce hospital-associated infections associated with medical devices.