Hydrophobic interaction chromatography (HIC) is an established production method for large-scale protein purification, but need to add lyotropic salts makes it costly and environmentally challenging
Peter Levison, technology development director at Pall, is presenting data on a unique new mixed-mode chromatography method combining hydrophobic and ionic components that give process chromatographers unprecedented versatility in protein purification, while also significantly reducing costs and environmental burdens.
He is presenting the results of this study as part of the scientific program at the 19th International Prep Symposia in Baltimore, Maryland.
The new Pall BioSepra PPA HyperCel and HEA HyperCel mixed-mode chromatography sorbents are capable of interacting with a range of proteins under physiological-type conditions (pH and ionic strength) without the need to add lyotropic salts at concentrations typical of those required for traditional HIC.
The added lyotropes require disposal following the adsorption and wash stages, resulting in additional expense beyond initial reagent costs, and can also significantly impact the environment, especially with large-scale production.
Dr Levison explains that the combined characteristics of HIC and ion exchange chromatography (IEX) in the new sorbents allow process chromatographers to adjust modalities to capture virtually any protein.
He shared data that shows the superior binding capacity of the new sorbents compared to conventional HIC sorbents.
For example, the mixed mode sorbents exhibited a binding capacity of ~50mg/ml for BSA in phosphate buffered saline, whereas no significant BSA binding capacity was observed for HIC chromatography under similar physiological conditions.
"HEA HyperCel and PPA HyperCel add universal protein purification tools to the Pall process chromatography toolbox," says Levison.
"These sorbents answer the need for innovation in downstream processing, the source of most of today's biopharmaceutical manufacturing bottlenecks due to increasingly larger yields produced upstream." The study evaluated the binding and elution properties of PPA and HEA HyperCel with a variety of proteins and more complex feedstreams.
It also included a comparison of PPA and HEA HyperCel with anion exchange, HIC and HCIC sorbents.
The effect of temperature on adsorption of BSA and ovalbumin was also investigated.
It was found that protein-binding capacity using the new sorbents increases as temperatures rise, demonstrating a similarity to HIC processes, even in the absence of lyotropes.
"Eliminating the need to add lyotropic salts provides a considerable economic and environmental benefit for chromatography operations," says Dr Levison.
"These sorbents also provide a higher yield and recovery under selected conditions."
