Surface Chemistry Influences Interfacial Fibrinogen Self-Association

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Protein Dynamics

Background:

• Surface chemistry modifications are crucial for controlling protein adsorption and aggregation in various applications.
• Understanding the kinetics of how surface properties influence protein behavior is essential but remains challenging.

Purpose of the Study:

• To investigate the influence of surface chemistry on the dynamics of fibrinogen (Fg) self-association and aggregation.
• To compare protein dynamics on hydrophobic (trimethyl silane - TMS) versus hydrophilic (oligoethylene glycol - OEG) surfaces.

Main Methods:

• Utilized intermolecular resonance energy transfer (RET) combined with high-throughput single-molecule tracking.
• Directly observed and quantified fibrinogen-fibrinogen associations and dissociations on modified surfaces.

Main Results:

• Fibrinogen desorption was slower from hydrophobic TMS surfaces than hydrophilic OEG surfaces at higher concentrations.
• Unassociated molecules showed a higher propensity to associate on TMS surfaces, indicating promotion of protein-protein interactions.
• Protein contact times and overall surface residence times increased more significantly with concentration on TMS surfaces compared to OEG surfaces.

Conclusions:

• Surface chemistry significantly influences not only protein-surface interactions but also promotes interfacial protein aggregation.
• Hydrophobic surfaces (TMS) appear to promote protein aggregation more effectively than hydrophilic surfaces (OEG), especially at higher protein concentrations.