Solution structure and direct imaging of fibronectin adsorption to solid surfaces by scanning force microscopy and...

Area of Science:

• Biophysics
• Materials Science
• Nanotechnology

Background:

• Understanding protein adsorption is crucial for biomaterial development and biosensor design.
• Fibronectin is a key extracellular matrix protein involved in cell adhesion and tissue repair.
• Characterizing protein behavior at interfaces requires high-resolution imaging techniques.

Purpose of the Study:

• To visualize single fibronectin molecules using scanning force microscopy (SFM) and electron microscopy.
• To investigate the influence of surface properties (chemical composition, surface tension) on fibronectin adsorption and spreading.
• To demonstrate SFM's capability in mapping nanoscale protein organization and orientation on diverse surfaces.

Main Methods:

• Single fibronectin molecules were visualized using scanning force microscopy (SFM) and electron microscopy.
• Surface characterization involved dynamic contact angle measurements, X-ray photoemission spectroscopy (XPS), and SFM.
• Protein adsorption and film formation were studied using surface plasmon resonance spectroscopy.

Main Results:

• Fibronectin spreading on surfaces was dependent on the substrate's chemical composition and surface tension.
• SFM and electron microscopy revealed fibronectin adopts an extended, straight strand conformation in solution and on surfaces.
• SFM accuracy was validated by imaging DNA, with measured contour lengths being accurate.

Conclusions:

• SFM is a powerful tool for nanoscale imaging of protein adsorption and organization.
• Surface properties significantly influence fibronectin adsorption behavior and molecular conformation.
• This study provides insights into protein-surface interactions relevant to biomaterials and nanotechnology.