Size-Dependent Protein Adsorption on a Nanoparticle

Area of Science:

• Surface Chemistry
• Nanoparticle Science
• Biophysics

Background:

• Understanding protein adsorption on charged surfaces is crucial for biomaterial design and diagnostics.
• Previous models often simplify the complex interplay between surface charge, solution chemistry, and protein behavior.

Purpose of the Study:

• To develop a comprehensive numerical model for protein adsorption onto charged silica nanoparticles.
• To investigate the influence of surface properties and solution parameters on protein adsorption mechanisms within the electrical double layer (EDL).

Main Methods:

• Coupling a charge regulation model with three protein adsorption models (Classical Langmuir, Extended Langmuir, Two-State).
• Systematic variation of parameters including ionic concentration, pH, surface charge density, and nanoparticle (NP) diameter.
• Numerical simulation of protein adsorption considering surface curvature and protein conformational changes.

Main Results:

• The model successfully simulates size-dependent protein adsorption, agreeing well with experimental data.
• Demonstrated profound influence of space charge density, surface chemistry, and NP morphology on adsorption characteristics.
• Revealed the combined effects of surface curvature, conformational changes, and pH-dependent protein behavior.

Conclusions:

• The developed numerical model provides a unified framework for studying protein adsorption on charged NPs.
• Surface properties and solution conditions significantly dictate protein adsorption mechanisms and outcomes.
• This work advances the understanding of nanoparticle-protein interactions in aqueous environments.