Laser Processing of Polymer Films Fabricated from PHAs Differing in Their Monomer Composition

Area of Science:

• Materials Science
• Biomaterials Engineering
• Surface Chemistry

Background:

• Polyhydroxyalkanoates (PHAs) are biodegradable polymers with potential biomedical applications.
• Surface properties of PHAs, such as hydrophilicity and roughness, influence their biocompatibility.
• Controlling surface characteristics is crucial for tailoring PHA interactions with cells.

Purpose of the Study:

• To investigate the effects of CO2 laser treatment on the surface properties of various PHA films.
• To evaluate how different laser modes (continuous wave vs. quasi-pulsed) impact PHA surface characteristics.
• To assess the influence of laser-modified PHA surfaces on NIH 3T3 fibroblast attachment and proliferation.

Main Methods:

• Solvent casting was used to prepare PHA films from poly-3-hydroxybutyrate (P(3HB)) and its copolymers.
• CO2 laser treatment was applied in continuous wave and quasi-pulsed modes with specified power and speed settings.
• Surface properties including water contact angle, surface energy, and roughness were measured.
• Cell metabolic activity (MTT assay) was used to quantify fibroblast attachment on treated and untreated films.

Main Results:

• Laser treatment significantly altered PHA film surface properties, including water contact angle, surface energy, and roughness.
• Continuous wave laser treatment resulted in sintered grooves and reduced roughness, while quasi-pulsed treatment created pits.
• Quasi-pulsed laser treatment led to a more pronounced decrease in water contact angle and increased fibroblast attachment (1.26-1.76 fold increase).
• P(3HB) films showed distinct responses compared to copolymer films, highlighting the role of PHA composition.

Conclusions:

• CO2 laser treatment offers a method for targeted surface modification of PHA films.
• Quasi-pulsed laser irradiation enhances the biocompatibility of PHA films by promoting cell attachment.
• These findings provide a basis for designing PHA-based materials with controlled cellular interactions for biomedical applications.