Bacterial adhesion onto azidated poly(vinyl chloride) surfaces

Area of Science:

• Polymer Chemistry
• Biomaterials Science
• Microbiology

Background:

• Bacterial adhesion to medical devices is a major cause of device-associated infections.
• Developing novel antimicrobial surfaces is crucial for improving patient outcomes.
• Poly(vinyl chloride) is a common material in medical devices, but prone to biofilm formation.

Purpose of the Study:

• To modify poly(vinyl chloride) surfaces to reduce bacterial adhesion.
• To investigate the role of azide functional groups in preventing bacterial colonization.
• To assess the impact of surface hydrophilicity on bacterial adherence.

Main Methods:

• Plasticized poly(vinyl chloride) surfaces were modified via azidation using sodium azide and a phase transfer catalyst.
• Azidated surfaces were subsequently crosslinked using ultraviolet radiation.
• Contact angle measurements assessed surface hydrophilicity; bacterial adhesion assays used Staphylococcus aureus and Escherichia coli.

Main Results:

• Azidation rendered the poly(vinyl chloride) surface hydrophilic; further photoirradiation had no effect on hydrophilicity.
• Azidated surfaces exhibited significantly reduced adhesion of both Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) bacteria.
• Control and photocrosslinked surfaces showed no significant difference in bacterial adhesion compared to azidated surfaces.

Conclusions:

• The presence of intact azide functional groups on the polymer surface is responsible for the observed reduction in bacterial adherence.
• Surface hydrophilicity/hydrophobicity did not play a significant role in bacterial adhesion in this study.
• Covalently binding azide groups to polymer surfaces presents a promising strategy for combating bacterial colonization on medical devices.