A CONTINUUM HARD-SPHERE MODEL OF PROTEIN ADSORPTION

Area of Science:

• Biophysics
• Surface Science
• Computational Fluid Dynamics

Background:

• Protein adsorption is crucial for biological processes like cell interactions and blood coagulation.
• Traditional models like random sequential adsorption (RSA) and continuum equations have limitations in predicting adsorption kinetics.
• Brownian dynamics (BD) simulations offer a powerful tool for modeling protein adsorption at the mesoscale.

Purpose of the Study:

• To develop a continuum model that incorporates results from Brownian dynamics simulations for protein adsorption.
• To enable the integration of mesoscale simulation data into micro- or macro-scale computational fluid dynamics (CFD) simulations.
• To accurately predict the kinetics of protein adsorption in practical devices.

Main Methods:

• Developed a continuum model using Brownian dynamics simulations to define boundary conditions for CFD simulations.
• Modeled diffusive transport and adsorption of hard-sphere particles using BD simulations.
• Analyzed particle configuration to quantify near-surface chemical potential as a function of distance and surface coverage.
• Derived a continuum adsorption model based on the quantified chemical potential.
• Discretized and coupled the continuum model equations with CFD simulations for diffusive transport.

Main Results:

• The near-surface chemical potential was found to be dependent on distance from the surface and fractional surface coverage.
• The derived continuum model accurately incorporated BD simulation results.
• The continuum model's predicted adsorption kinetics closely matched the outcomes of the BD simulations.

Conclusions:

• The developed continuum model successfully bridges mesoscale BD simulations with macroscale CFD simulations for protein adsorption.
• This integrated approach enhances the predictive capability for protein adsorption kinetics in various applications.
• The model facilitates the simulation of protein adsorption in practical devices by linking different scales of simulation.