Researcher(s)
- Zachary Bernhart, Chemical Engineering, University of Delaware
Faculty Mentor(s)
- Abraham Lenhoff, Chemical and Biomolecular Engineering, University of Delaware
Abstract
Monoclonal antibodies (mAbs) are proteins produced using recombinant DNA technology that mimic the specific binding capabilities of natural antibodies and are consequently used for treating diseases such as cancer, asthma, and autoimmune diseases. However, within the harvested cell culture fluid (HCCF) that is obtained from the bioreactor are also other proteins, host-cell proteins (HCPs), that must be removed during purification to avoid deleterious effects on the mAb, the formulation, or the patient. The first step in removing HCPs from the HCCF in mAb production is typically protein A chromatography, which exploits protein A’s high affinity for the mAb. However, this step does not remove all the HCPs, especially those that form heteroaggregates with mAbs and DNA. Since these aggregates can be retained on the protein A resin surface, in this project a version of resin was generated on core-shell particles where protein A is immobilized within the core while little is expected to bind on the hydrophilic shell. This new resin was successful at reducing aggregate retention but had a low binding capacity and retained higher quantities of HCPs than expected. Since possible remaining HCP retention during protein A purification is likely due to HCP-protein A or HCP-mAb association, a second wash was added to the chromatography procedure to disrupt these interactions. Future research involves changing the protein ligand to reduce HCP retention through HCP-protein A association and increasing the ligand density to increase binding capacity and yield more mAb for each chromatography run.