Surface properties and platelet reactivity of segmented poly(etherurethanes) and poly(etherurethaneureas).

Area of Science:

• Polymer Science
• Materials Science
• Biomaterials

Background:

• Segmented poly(etherurethanes) (SPUs) and poly(etherurethaneureas) (SPUUs) are advanced polymers with tunable properties.
• Understanding their surface behavior in different environments is critical for biomaterial applications.

Purpose of the Study:

• To investigate the surface characteristics of SPUs and SPUUs in both air-equilibrated and hydrated states.
• To correlate surface reorganization with interfacial free energy minimization and contact angle hysteresis.
• To assess the impact of surface structure on blood compatibility, specifically platelet adhesion.

Main Methods:

• Preparation of segmented poly(etherurethanes) (SPUs) and poly(etherurethaneureas) (SPUUs) with varied hard and soft segments.
• Surface characterization using X-ray photoelectron spectroscopy (XPS) in air and hydrated states.
• Dynamic contact angle measurements to assess surface wettability and hysteresis.
• Platelet adhesion tests to evaluate blood compatibility.

Main Results:

• XPS analysis showed enrichment of low surface free energy components in air and high surface free energy components in water.
• Significant surface reorganization was observed upon transition from air to water, driven by interfacial free energy minimization.
• Large contact angle hysteresis was detected, primarily attributed to this surface reorganization process.
• Platelet adhesion was significantly influenced by the presence of surface microphase separated structures.

Conclusions:

• SPUs and SPUUs exhibit environment-dependent surface reorganization to minimize interfacial free energy.
• Contact angle hysteresis is a key indicator of this dynamic surface behavior.
• The microphase separated surface structure of these polymers is vital for achieving good blood compatibility.