Platelet adhesion onto segmented polyurethane surfaces modified by PEO- and sulfonated PEO-containing block copolymer...

Area of Science:

• Materials Science
• Biomaterials Engineering
• Polymer Chemistry

Background:

• Segmented polyurethanes (PU) are widely used biomaterials.
• Surface modification is crucial for improving biocompatibility and reducing adverse biological responses.
• Polyethylene oxide (PEO) is known for its protein-repellent and biocompatible properties.

Purpose of the Study:

• To investigate the surface modification of PU films using amphiphilic block copolymers containing polyethylene oxide (PEO).
• To evaluate the effect of PEO chain length and sulfonation on surface properties and platelet adhesion.
• To understand the relationship between PEO additive characteristics and polyurethane film performance.

Main Methods:

• Preparation of PU films with varying PEO-containing amphiphilic block copolymers (PEO-PPO-PEO triblock copolymers).
• Characterization using dynamic water contact angle measurements and electron spectroscopy for chemical analysis.
• Assessment of mechanical properties (tensile strength, elongation) and water absorption.
• Evaluation of platelet adhesion on modified surfaces.

Main Results:

• PU films with 10 wt% PEO additives achieved surface saturation, with longer PEO chains projecting further.
• Water absorption increased significantly with longer PEO chains, creating a gel-like surface state.
• Platelet adhesion decreased as PEO chain length increased; long PEO chains (length 80) were highly effective in prevention.
• The anti-adhesion effect of sulfonate groups was observed only with short PEO chains, with chain mobility being dominant for longer chains.

Conclusions:

• Polyethylene oxide additives effectively modify polyurethane surfaces, enhancing biocompatibility by reducing platelet adhesion.
• The length of the PEO chains in the additives plays a critical role in surface properties and anti-thrombogenic performance.
• Surface chain mobility, influenced by PEO chain length, is a key factor in preventing platelet adhesion, often outweighing the effect of surface charge.