Platelet adhesion on the gradient surfaces grafted with phospholipid polymer

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Surface Chemistry

Background:

• Blood-compatible materials are crucial for medical devices.
• Existing materials often trigger adverse biological responses.
• Omega-methacryloyloxyalkyl phosphorylcholine (MAPC) polymers show promise due to their phospholipid affinity.

Purpose of the Study:

• To synthesize and evaluate MAPC polymers for blood compatibility.
• To investigate the effect of MAPC chemical structure on blood compatibility.
• To create a gradient poly(MAPC)-grafted polyethylene surface to study these effects.

Main Methods:

• Synthesis of MAPC polymers.
• Corona discharge treatment to graft poly(MAPC) onto polyethylene (PE).
• X-ray photoelectron spectroscopy (XPS) for surface composition (P/C ratio).
• Contact angle measurements for surface hydrophilicity.
• Platelet adhesion tests.

Main Results:

• Gradient poly(MAPC) grafting on PE was achieved, confirmed by increasing P/C ratio and decreasing water contact angle with corona irradiation energy.
• Surface density of MAPC units increased and plateaued, indicating complete surface coverage.
• Longer methylene chains in MAPC enhanced phospholipid exposure and surface hydrophobicity.
• Platelet adhesion significantly reduced on surfaces with constant P/C ratio.

Conclusions:

• MAPC polymers exhibit excellent blood compatibility due to biomembrane-like surface formation via phospholipid adsorption.
• Surface modification of PE with MAPC, controlled by corona discharge, effectively improves blood compatibility.
• The chemical structure, specifically methylene chain length, influences surface properties and blood interaction.