The Role of Chromatography in Bioprocessing Optimization

As worldwide demand for precision medicine continues to expand to address unmet patient needs, so has the development and manufacturing of novel therapeutics within various biomedical sectors. Revenue in the pharmaceuticals market is projected to grow at a compound annual rate of 4.71 percent and reach a market volume of 1,454 billion USD by 2029 (1). However, the increase in the diversity and complexity of biopharmaceutical products, such as biologics, cell and gene therapies, and vaccines, is met with challenges in downstream bioprocessing.

Taking clinical applications, scalability, and biochemical and biophysical properties into consideration, streamlined chromatography techniques are increasingly utilized to improve bioprocessing capabilities to meet current and anticipated market demand. Accelerated production must be accomplished without compromising the yield, purity, efficacy, or safety of the end-product. Therefore, access to a range of cost-effective, high-specificity chromatography tools (e.g., resins, columns, and liquid chromatography systems) that can isolate and purify molecules of interest, and are secure in their supply, to meet both small- and large-scale production needs is essential.

Purification challenges
 

Bioprocessing often requires a series of steps, aiming to recover and purify a molecule of interest from a complex mixture of DNA, host cell proteins, protein aggregates, endotoxins, cellular debris, and other cell culture by-products. Ramping up multi-step chromatography workflows from development to manufacturing can be challenging because of differences in column size, flow rate, and resin properties. Thus, purification conditions optimized at the small scale might be suboptimal for large-scale bioprocessing efforts. To address these challenges, it is important to carefully optimize process parameters and conduct thorough scale-up studies to ensure successful implementation at manufacturing scale. Additionally, each target biomolecule presents a unique set of challenges necessitating the tailoring of purification strategies to the specific therapy in order to recover high-quality product free from impurities.

Column quality is essential for establishing a streamlined and reliable protocol. Process complexity introduces several challenges, including column preparation and quantification, resin availability, hardware availability and storage, and user expertise and training. Additionally, packing large or multiple columns may create process bottlenecks, variability in quality and performance, and lack of reproducibility.

Depending on specific biomolecule properties, different modes of interaction – such as affinity, ion exchange (IEX), size-exclusion (SEC), and hydrophobic interaction (HIC) – can be leveraged. By combining multiple interaction modes into a single resin, multimodal (mixed-mode) chromatography (MMC) is a highly selective and robust method for removing a range of impurities in fewer purification steps, making it an attractive option for time and cost savings in industry.

Along with the rise of MMC, the adoption and implementation of ready-to-use prepacked chromatography columns has played a critical role in process optimization, accelerating the speed of manufacturing biotherapeutics, and lowering costs. Columns that are manufactured under Good Manufacturing Practice (GMP) conditions, ensure consistent performance and reduce contamination risks by avoiding errors that may occur during manual packing. They also save time, increase productivity, and reduce downtime, eliminating the need for specialized equipment and expertise. Vendors offering prepacked columns can help facilitate scale-up operations by providing columns of various sizes, packed with different resins, along with detailed instructions, documentation, and the necessary hardware. Users expect prepacked columns to meet all necessary specifications to ensure straightforward scale-up. In addition, some suppliers manufacture both the resin and prepacked columns, allowing them to pack the column with a single batch of resin and provide a warranty for their columns. This offers users a single-source solution, greater consistency, and purchase security. In addition to prepacked, ready-to-use columns, automated liquid chromatography systems can save time and improve reproducibility of multi-step protocols. With preconfigured or custom configuration options as well as support for multi-dimensional workflows, automated systems meet a range of throughput and application needs. Integrated software platforms enable flexibility in process development, real-time monitoring and control, and analysis.

We have demonstrated recent examples that highlight the advantages of MMC and automated systems that are applicable to production of biopharmaceuticals. Combination HIC and IEX in a single resin has been shown to provide optimized recombinant adenovirus purification (2). Similarly, hydroxyapatite chromatography mixed-mode media can bind a wide range of viral particles and separate them from impurities through calcium affinity and cation exchange interactions. In another recent study we conducted, automated tandem immunoglobulin antibody purification with inline pH neutralization and SEC showed reductions in low pH exposure and aggregation as well as sample loss (3). The resulting increases in end-product yield and purity at tens-of-milligrams scale demonstrate key benefits for biologics production.

With numerous clinical applications for biologics and viral vectors, as well as increased interest and need for rapid development and production of vaccines, the demand for bioprocessing optimization at manufacturing-scale is on the rise. The biological/biochemical and physicochemical complexities associated with purification of biotherapeutics present several challenges to their production that necessitate innovative and cost-effective solutions. The use of MMC can offer versatility in process design and improve end-product homogeneity and purity for a wide variety of target biomolecules, while prepacked columns ensure adherence to strict performance criteria. Further, growing automation capabilities will promote the development of high-throughput purification strategies and promise to bolster large-scale biopharmaceutical manufacturing.