Improving Protein Productivity in CHO Biomanufacturing using Media Supplementation

By on March 14, 2016
Expert Session Summaries

We recently finished our Ask the Expert discussion on “How to Improve Protein Productivity Through Scale Up, Including Single-Use Bioreactors”. During this Ask the Expert session, we discussed improving protein productivity in CHO biomanufacturing through the addition of a defined supplement/feed. Specific topics included adding lipids, purification, glycosylation profiles, and impact on CHO cell lines, transfection pools, MDCK lines and HEK cell lines.

Enhancing protein production is a common goal in the CHO biomanufacturing industry. However, scalability is a problem faced across many platforms in manufacturing. A desired outcome observed in shake flasks, such as increased protein productivity, is not always observed in large scale bioreactors. Further, the move toward single-use bioreactors has posed an additional challenge, as productivity improvements observed in glass shake flasks or stainless steel bioreactors may not be observed in plastic bioreactor bags. Availability of lipids in media is one factor to consider during CHO biomanufacturing scale-up and when moving toward single-use system.

In this Ask the Expert session, Dr. Adam Elhofy, Ph.D., CSO, discussed how Essential Pharmaceuticals is addressing these challenges with their Cell-Ess lipid supplement. Cell-Ess was used as a feed at 5% (v/v) in a small Wave bioreactor resulting in greater than 25% monoclonal antibody titer increase, which was similar to the gains seen in earlier experiments using shake flasks. Small bioreactors have been used as models to show scalability to up to 10,000-liter manufacturing runs. These new data suggest supplementing with Cell-Ess as a feed will result in increased monoclonal antibody titers for 10,000-liter bioreactor runs, including in single-use bioreactors.

Dr. Elhofy developed the core technology for the Ess line of products and aided in creating patents around novel uses of materials.  Dr. Elhofy has over 14 years of scientific research experience in the areas of immunology, neuroscience, and oncology.  He was funded by both the National Institutes of Health and the Multiple Sclerosis society as an investigator at Northwestern University Medical School. His doctoral research won him the award of the Top 5 trainee scientists by the American Association of Immunologists. Dr. Elhofy has 14 scientific publications in peer reviewed journals. He has played a variety of roles with start-up biotech companies ranging from Principal Investigator to Director of Corporate Development.

Below is a sneak peek of the discussion, for a full transcript, please see – Ask the Expert – How to Improve Protein Productivity Through Scale Up, Including Single-Use Bioreactors.

Question:

Each time we add lipids to our media, we must make fresh solution and titrate the appropriate amount to add to avoid cell death. Do we have to undergo the same process with your supplement?

The Answer:

Cell-Ess is stable in solution. There are issues with free fatty acid and free cholesterol with stability and solubility. In addition, the carrier may cause a problem. All of these issues have to be monitored and accounted for in cultures lasting over 4 days. With longer cultures, media depletion becomes a concern, and feeds are used to supplement the culture. For free fatty acids, free cholesterol, or cholesterol with a carrier in extended cultures, toxicity becomes a concern with the second or third feed and can be variable from run to run based on the break down or initial stability of the product. Cell-Ess deploys a novel method of delivery so these are not issues when optimized with Cell-Ess.

Question:

Do you know which CHO cell lines are more impacted by the addition of lipids in the media?

The Answer:

Cell-Ess has been tested on several CHO cell lines. The effect has been similar across the different genetic backgrounds. The amount of Cell-Ess used varies more based on the SFM used to grow the CHO cells. Once an optimized stragtegy is reached, the increase in titer is typically and reproducibly in the 20%-30% range.

Question:

We work with CHO transfection pools for protein production. We typically use a more complex media for this application. Have you seen your product can be helpful with transfection pools?

The Answer:

We have seen a benefit in CHO cell pools. As with isolated clones used for production, the base SFM drives the amount of Cell-Ess needed for an observed benefit. The typical time for pools grown is shorter than that for production runs so most likely an initial supplement tends to be sufficient. We can work with you to give guidelines based on our experience what will work best for your specific goals.

For more information on this topic, please see the blog “New Advances Pose New Challenges to Bioproduction

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