Protein adsorption on surfaces with grafted polymers: a theoretical approach

Area of Science:

• Surface Science
• Polymer Science
• Biophysics

Background:

• Protein adsorption on surfaces is crucial in biomedical applications.
• Understanding the role of grafted polymers in modulating protein adsorption is essential.
• Existing theories often simplify the complex interactions at the polymer-surface interface.

Purpose of the Study:

• To present a general theoretical framework for protein adsorption on surfaces with grafted polymers.
• To investigate the influence of polymer surface coverage, protein concentration, and solvent type on adsorption.
• To calculate protein-surface potentials of mean force as a function of polymer properties.

Main Methods:

• Generalization of single-chain mean-field theory.
• Modeling the grafted polymer-protein-solvent layer as inhomogeneous perpendicular to the surface.
• Application to lysozyme adsorption on polyethylene oxide-grafted surfaces.

Main Results:

• Adsorption isotherms are calculable based on polymer coverage, protein concentration, and solvent.
• For neutral surfaces, lysozyme adsorption is independent of polymer length above 50 units.
• Attractive surface-monomer interactions qualitatively alter adsorption behavior; longer polymers are more effective at repulsion.

Conclusions:

• The developed theory provides a framework for predicting protein adsorption on grafted polymer surfaces.
• Polymer chain length and surface-monomer interactions significantly impact protein adsorption behavior.
• The structure and deformation of the polymer layer are critical factors in protein adsorption.