The biopharmaceutical landscape is evolving, necessitating innovative chromatographic techniques that surpass traditional methodologies like hydrophobic interaction chromatography (HIC), ion exchange chromatography, and affinity chromatography. As protein expression levels and feedstock volumes have surged, especially with fermenters capable of handling 12,000 to 15,000 liters, there is a pressing need for solutions that enhance efficiency and reduce costs in protein purification.
Shifting Industry Demands
Sylvio Bengio, a scientific communications manager at Pall Life Sciences, emphasizes that many established technologies from three decades ago are inadequate for current challenges. Although conventional Protein A affinity chromatography remains effective, its cost implications have led to a growing interest in alternatives, particularly mixed-mode chromatography sorbents and custom-designed ligands that can optimize purification processes.
Mixed-mode chromatography, while not a new concept, has seen significant advancements in the precise tailoring of its hydrophobic components, enabling researchers to enhance its application across various scenarios. This technique generally incorporates three key steps: capture, intermediate purification, and polishing. Traditional methods often fall short when faced with large feedstream volumes, necessitating dilution of feedstock that can complicate logistics at industrial scales.
Cost Challenges in Conventional Techniques
Monoclonal antibodies (mAbs) currently comprise over 35% of proteins in clinical trials, with Protein A chromatography being the go-to method for their purification. While its high selectivity allows for effective antibody capture from complex mixtures, the cost associated with Protein A sorbents is substantial. As antibodies are required in large quantities for therapeutic use, the pressure to reduce purification costs is mounting. Mixed-mode chromatography offers a potential solution by minimizing the number of steps and costs involved in the purification process.
Advantages of Mixed-Mode Resin Technology
Mixed-mode chromatography has been successfully integrated with HIC methods to create more efficient purification protocols. Conventional HIC requires the addition of substantial amounts of lyotropic salts, such as ammonium sulfate, to facilitate protein binding. This practice becomes problematic on a large scale due to the high costs and logistical issues associated with salt handling and disposal.
The introduction of new mixed-mode resins, such as Pall Life Sciences’ MEP HyperCel, offers a promising alternative. This resin allows for antibody binding at neutral pH directly from the feedstock, eliminating the need for extensive dilution and high salt concentrations. The binding mechanism of MEP HyperCel is versatile, accommodating various antibody isotypes and enabling elution at higher pH levels, which is beneficial for maintaining protein integrity.
Targeting Impurities in E. coli-Derived Proteins
MEP HyperCel is also effective for purifying recombinant proteins expressed in Escherichia coli. In this context, it binds proteins predominantly through hydrophobic interactions, requiring lower concentrations of lyotropic salts compared to conventional methods. The resin’s affinity for hydrophobic and negatively charged contaminants, such as lipopolysaccharides (LPS) and host-cell proteins, further enhances its utility. By selectively retaining these contaminants during elution, MEP HyperCel improves the overall purity of the target protein.
Innovations in Ligand Design
Advancements in mixed-mode chromatography are not limited to existing resins. Companies like GE Healthcare Bio-Sciences are leveraging combinatorial chemistry to create libraries of chromatographic ligands with diverse properties. This approach enables the fine-tuning of ligand characteristics to optimize selectivity for specific protein targets. By screening these libraries using high-throughput formats, researchers can rapidly identify promising candidates for various purification challenges.
Streamlining Processes with New Technologies
The advent of multimodal cation exchangers within GE’s Capto platform exemplifies the industry’s shift towards more efficient purification strategies. These media facilitate binding under high-salt conditions, reducing the need for feedstock dilution and streamlining purification processes. This innovation aligns with the broader goal of enhancing process economy and shortening time to market for biopharmaceutical products.
The Future of Protein Purification
The growing interest in mixed-mode chromatography underscores the need for more tailored and cost-effective purification strategies in biopharmaceutical manufacturing. The development of small synthetic ligands, which provide specific binding capabilities while being more stable and less expensive than traditional protein-based ligands, represents a significant evolution in the field.
These advancements offer the potential for better selectivity and increased yields in protein purification, paving the way for more efficient bioprocessing.
Key Takeaways
- Mixed-mode chromatography is evolving to address the complexities of modern biopharmaceutical production.
- Innovations in resin design, such as MEP HyperCel, enhance the purification of antibodies and recombinant proteins from challenging feedstreams.
-
High-throughput screening of chromatographic ligand libraries accelerates the discovery of tailored solutions for specific purification needs.
In conclusion, as the biopharmaceutical industry faces increasing demands for efficiency and cost-effectiveness, the integration of advanced mixed-mode chromatography technologies will play a pivotal role in shaping the future of protein purification. The potential for enhanced selectivity and reduced process steps not only promises to streamline operations but also to accelerate the delivery of critical therapeutics to the market.
Read more → www.pharmtech.com