Staphylococcus epidermidis adhesion to films deposited from hydroxyethylmethacrylate plasma

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Microbiology

Background:

• Bacterial adhesion to biomaterials is a significant clinical challenge.
• Controlling surface properties is crucial for mitigating biofilm formation.

Purpose of the Study:

• To investigate the adhesion of Staphylococcus epidermidis (S. epidermidis) to polystyrene (PS) surfaces modified with hydroxyethylmethacrylate (HEMA) plasma coatings.
• To compare adhesion on HEMA-plasma-coated PS with untreated and oxygen-plasma-treated PS.

Main Methods:

• Films of HEMA were deposited onto PS disks using plasma polymerization at varying discharge powers (40-100 W).
• Surface characterization included Electron Spectroscopy for Chemical Analysis (ESCA) for chemistry, contact angle measurements for energetics, and Atomic Force Microscopy (AFM) for morphology.
• Bacterial adhesion assays were performed using S. epidermidis ATCC 35984.

Main Results:

• S. epidermidis ATCC 35984 exhibited greater adhesion to both plasma-deposited HEMA-coated and oxygen-plasma-treated PS surfaces compared to untreated PS.
• No significant differences in bacterial adhesion were observed among HEMA-coated surfaces prepared under different deposition power conditions.
• Surface energetic analysis indicated a strong Lewis-base character for plasma-modified surfaces.

Conclusions:

• Plasma-deposited HEMA coatings and oxygen plasma treatment increase S. epidermidis adhesion on polystyrene.
• Surface energetics, particularly Lewis-base character, play a critical role in bacterial adhesion.
• Electron donor-acceptor interactions are hypothesized to be a primary mechanism driving bacterial adhesion to these modified surfaces.