Molecular interaction forces generated during protein adsorption to well-defined polymer brush surfaces

Area of Science:

• Surface Science
• Materials Science
• Biophysics

Background:

• Protein adsorption to surfaces is a critical phenomenon in biomaterials and biosensing.
• Understanding molecular interactions at interfaces is key to controlling surface properties.

Purpose of the Study:

• To investigate molecular interaction forces during protein adsorption.
• To evaluate the protein-repellency of various polymer brush surfaces.

Main Methods:

• Atomic force microscopy (AFM) for force-distance (f-d) curve measurements.
• Surface-initiated atom transfer radical polymerization to create polymer brush substrates.
• Surface plasmon resonance (SPR) to quantify protein adsorption.

Main Results:

• Cationic and anionic polymer brushes exhibited electrostatic repulsion, while hydrophobic brushes showed strong adhesion.
• Zwitterionic polymer brushes demonstrated minimal interaction forces.
• Protein adsorption was high on oppositely charged polyelectrolyte brushes and hydrophobic brushes.
• Zwitterionic brushes effectively suppressed protein adsorption.

Conclusions:

• Surface-induced direct interaction forces significantly influence protein adsorption.
• Zwitterionic polymer brush layers are promising for developing protein-repellent surfaces.
• Minimizing interfacial interactions is crucial for preventing unwanted protein adhesion.