Pore-blocking steric mass-action model for adsorption of bioparticles

Area of Science:

• Biochemical Engineering
• Separation Science
• Chromatography

Background:

• Steric mass-action (SMA) model is standard for protein adsorption in chromatography.
• Large bioparticles exhibit unique pore-blocking behavior, limiting ligand accessibility.

Purpose of the Study:

• Develop a pore-blocking steric mass-action (PB-SMA) model for large bioparticle adsorption.
• Improve accuracy in describing bioparticle-ligand interactions in chromatography.

Main Methods:

• Introduced an inaccessible ligand density parameter (L_in) to the SMA model.
• Developed the PB-SMA model for inactivated foot-and-mouth disease virus (iFMDV) on IMAC adsorbents.
• Validated the model with hepatitis B surface antigen virus-like particles (HBsAg VLPs) on ion exchange adsorbents.

Main Results:

• PB-SMA model yielded significantly smaller steric factors (σ) compared to conventional SMA.
• PB-SMA steric factors more accurately reflected theoretical ligand shielding by adsorbed bioparticles.
• Model demonstrated improved accuracy for both iFMDV and HBsAg VLPs adsorption.

Conclusions:

• The PB-SMA model provides a more accurate description of large bioparticle adsorption in chromatography.
• Accounting for pore-blocking is crucial for precise modeling of bioparticle-adsorbent interactions.
• The PB-SMA model is applicable to various bioparticles and chromatographic adsorbents.