Continuous aqueous two-phase extraction of human antibodies using a packed column

Area of Science:

• Biochemical Engineering
• Separation Science
• Biotechnology

Background:

• Continuous counter-current aqueous two-phase extraction (ATPE) is crucial for biopharmaceutical purification.
• Optimizing ATPE systems for high recovery and purity of therapeutic proteins like human immunoglobulin G (IgG) remains a challenge.

Purpose of the Study:

• Evaluate a pilot-scale packed differential contactor for continuous IgG extraction from Chinese hamster ovary (CHO) cell supernatant.
• Select optimal dispersed phase and column packing material for efficient IgG ATPE.

Main Methods:

• Screening of phosphate-rich versus polyethylene glycol (PEG)-rich phases and stainless steel packing material.
• Hydrodynamic studies using Richardson-Zaki and Mísek equations.
• Performance evaluation of a packed column integrated with a pump mixer-settler stage.

Main Results:

• Selected PEG-rich phase as dispersed and stainless steel as packing material due to favorable wetting properties.
• Achieved 85% IgG recovery with over 85% removal of contaminant proteins.
• Mass transfer was found to be controlled by the PEG-rich phase.

Conclusions:

• The pilot-scale packed differential contactor with a PEG-rich dispersed phase and stainless steel packing is effective for continuous IgG ATPE.
• Integration with a pump mixer-settler stage enhances performance, offering advantages over batch extraction.
• Further efficiency gains are possible with additional mixer-settler stages and higher flow rates.