Protein A chromatography at high titers

Area of Science:

• Biopharmaceutical Manufacturing
• Chromatographic Separation Science
• Chemical Engineering

Background:

• Increasing monoclonal antibody (mAb) titers present downstream processing challenges.
• Protein A chromatography is a critical step in mAb purification.
• Quantitative data on feed concentration effects on dynamic binding capacity (DBC) are lacking.

Purpose of the Study:

• To investigate the impact of feed concentration on Protein A chromatography DBC.
• To understand the underlying mechanisms of DBC reduction at high mAb titers.
• To provide a framework for optimizing Protein A capture steps for high-titer products.

Main Methods:

• Small-scale experiments using ProSep® Ultra Plus columns.
• Systematic variation of feed flow rates and mAb concentrations.
• Mathematical modeling based on linear driving force and solid phase diffusion.

Main Results:

• Dynamic binding capacity (DBC) significantly decreases with increasing mAb concentration at short residence times.
• Observed DBC reduction is attributed to non-equilibrium mass transfer effects within the resin pores.
• Experimental data align with predictions from a mathematical model incorporating solid phase diffusion.

Conclusions:

• Feed concentration is a critical parameter affecting Protein A chromatography performance.
• Non-equilibrium mass transfer limits DBC in high-titer mAb purification.
• The findings offer guidance for designing efficient Protein A capture steps for large-scale bioprocessing.