Catch the WAVE – A Review of our Ask the Expert Session on using the WAVE Bioreactor for Research and Manufacturing Operations

By on July 17, 2013
GE Healthcare's WAVE Bioreactor 2050, courtesy of GE Healthcare.

Last week, we finished our Ask the Expert discussion on using the WAVE bioreactor for research and manufacturing operations. Several questions were asked about culturing specific cell lines using the WAVE bioreactor including HEK, BHK, Vero, NS0 and Insect cell lines. Other questions involved unique features of the WAVE system, use of WAVE in perfusion mode and addressing specific culture conditions including pH and hypoxic conditions.

An early pioneer in the area of disposable bioreactors, the WAVE Bioreactor was the first single-use bioreactor system when it was presented to the bioprocessing community in 1996. Since then, the range of products has expanded to include larger scale systems and advanced optical sensor and control technologies. WAVE Bioreactor systems are today widely used in both research and manufacturing operations. The latest WAVE bioreactor, ReadyToProcess WAVE 25, combines the ease-of use that comes with the rocking technology as such, with intelligent control and advanced sensor technology. These were the topics covered last week’s Ask the Expert Session.

The session, hosted by Christian Kaisermayer, who currently holds the position of senior scientist at GE Healthcare, received several questions across a wide range of topics and cell lines. Mr. Kaisermayer, provided insightful answers based on his extensive experience with the WAVE bioreactor system.

Question topics included:

  • HEK Culture
  • BHK Culture
  • Cultivating NS0 Cells
  • Insect Cell Culture
  • Virus Manufacturing
  • Banking Vero Cells
  • Controlling pH
  • WAVE System in perfusion mode
  • Hypoxic Culture Conditions
  • Unique Features of the WAVE Bioreactor

I have selected a few of the submitted questions and answers to include below. For a full list of questions and answers, please see Ask the Expert discussion on using the WAVE bioreactor for research and manufacturing operations

Question:

We want to cultivate cholesterol dependent NS0 cells in a Wave reactor. It is said that cholesterol is adsorbed to the bag film. What can be done to achieve a sufficient concentration of the lipid in the culture?

The Answer:

The problem of cholesterol delivery to NS0 cells was investigated when differences in cell growth were observed in serum containing culture and serum free medium supplemented with lipids and synthetic cholesterol. The conclusion of the authors was that the interaction of the lipid carrier, in this case methyl-beta-cyclodextrin, with the bag film led to cholesterol depletion of the culture. This problem was solved by reducing the excess ratio of lipid carrier to cholesterol, which allowed successful cultivation of NS0 cells in the WAVE Bioreactor. Details: Okonkowski J et al. 2007 J. Biosci Bioeng 103(1):50-59.

Question:

In my lab we are working on producing antibody using hybridoma for both in-vivo studies and also pre-clinical work. We are using shake flask, but now need to produce more volume. I am wondering what system you would suggest for smaller scale production and if you would recommend perfusion culture or not.

The Answer:

Multiple hybridoma cell lines have been successfully cultivated in WAVE Bioreactor systems. Using different Cellbag bioreactors, cultivation volumes from < 0.5 L to 25 L can be run on the same instrument. After an initial characterization of the cultivation process in batch mode, a process optimization targeting perfusion is a viable option to increase the volumetric productivity of hybridomacultures.

An example for such a perfusion process can be found in: Tang Y. et al. 2007. Biotechnol. Prog. 23(1):255-264. The study showed a 10-fold increase of the viable cell concentration when switching from batch to perfusion culture. This resulted in a substantially higher volumetric productivity and an overall 7-fold increase in the amount of antibody produced in perfusion culture.

Question:

I am interested in a flexible perfusion setup to achieve high cell concentrations in insect cell culture. I am using SF 9 cells and would like to run initial experiments at small volumes of 1 to 3 L. Furthermore I am interested in an option for scale-up at a later time.

The Answer:

Perfusion cultures can be run using Cellbag bioreactors with integrated filter for cell retention. Harvest can be withdrawn directly through the filter, using a harvest line that ends in a luer connector at the bag wall. The filter has a nominal pore size of 7 µm and floats on top of the culture liquid. The lateral movement during the rocking of the bioreactor delays cell attachment thus, improving filter lifetime. In WAVE 25 an improved perfusion control is available, which allows continuous harvest and has an auto-calibration function to accurately maintain the perfusion rate. The fact that no recirculation loop is required makes this option quick and simple to set up. The integrated cell retention filter is available for culture volumes from 1 to 25 L.

Such a setup has been tested for insect cells, resulting in very high cell concentrations and recombinant protein production. Details can be found in: Wang L. et al. 2012 Mol. Biotechnol. 52(2):170-179

For an option that allows an exchange of the filter during the perfusion process, an external hollow fiber cartridge can be used to retain the cells. A study on the use of this cell retention can be found in: Clincke M. et al. 2013 Biotechnol. Prog. 29(3):754-767.

Please visit this week’s Ask the Expert session

How to Ensure Integrity and Sterility of Single-Use Assemblies in Manufacturing,” hosted by Carla Conant, Global Product Manager, ATMI LifeSciences.

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