Bovine Serum Albumin Interaction with Polyanionic and Polycationic Brushes: The Case Theoretical Study

Area of Science:

• Biophysics
• Polymer Science
• Surface Chemistry

Background:

• Understanding protein-surface interactions is crucial for biomaterials and drug delivery.
• Polyelectrolyte brushes are widely used in surface modification due to their tunable properties.
• Bovine Serum Albumin (BSA) is a model globular protein for studying protein adsorption.

Purpose of the Study:

• To develop a theoretical framework for predicting Bovine Serum Albumin (BSA) adsorption onto polyelectrolyte brushes.
• To investigate the influence of brush charge, pH, and ionic strength on protein-brush interactions.
• To elucidate the mechanisms governing protein absorption and expulsion.

Main Methods:

• Coarse-grained self-consistent field Poisson-Boltzmann framework.
• Incorporation of re-ionization free energy, osmotic forces, and hydrophobic interactions.
• Calculation of position-dependent insertion free energy.

Main Results:

• Predicts conditions for thermodynamically favorable BSA absorption or hindered absorption (expulsion).
• Demonstrates that polyanionic brushes offer broader pH range for BSA absorption compared to polycationic brushes.
• Highlights the role of BSA re-ionization within the brush in modulating absorption.

Conclusions:

• The developed model accurately predicts BSA-polyelectrolyte brush interactions.
• Re-ionization of protein residues significantly impacts adsorption behavior.
• The findings are applicable to designing surfaces for controlled protein interaction.