Analysis of Interaction Between Interfacial Structure and Fibrinogen at Blood-Compatible Polymer/Water Interface

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Polymer Science

Background:

• Understanding polymer/water interfaces is crucial for developing biocompatible materials.
• Protein adsorption at interfaces can lead to adverse biological responses, such as thrombogenesis.
• Poly(2-methoxyethyl acrylate) (PMEA) is recognized for its excellent blood compatibility.

Purpose of the Study:

• To investigate the relationship between interfacial nanostructure and protein adsorption.
• To elucidate the mechanism of fibrinogen (FNG) interaction with PMEA/water interfaces.
• To determine the role of water-rich domains in preventing protein adsorption and thrombogenesis.

Main Methods:

• Atomic force microscopy (AFM) was used to probe interactions between interfacial structures and fibrinogen.
• Topographic and phase image analyses were employed to study FNG adsorption.
• Phase separation of PMEA and water was induced to create nanometer-scale structures.

Main Results:

• Nanometer-scale polymer-rich and water-rich domains were observed at the PMEA/phosphate buffered saline interface.
• Fibrinogen (FNG) showed attractive interactions with polymer-rich domains but repulsive interactions with water-rich domains.
• Adsorbed FNG on PMEA surfaces, even in polymer-rich areas, demonstrated easy desorption.
• FNG did not adsorb into the water-rich domains, confirmed by AFM imaging.

Conclusions:

• Water molecules within the water-rich domains are the primary factor preventing FNG adsorption.
• The observed interfacial structure and water domain behavior contribute to PMEA's low thrombogenesis.
• These findings highlight the importance of interfacial water structuring in designing advanced biomaterials.