The control system allows for seamless transitions between bioprocess protocols, which allows us to use a single bioprocess control station to compare the performance of batch, fed-batch, and perfusion processes. This is crucial to our research, because the ease of conversion between methods is part of our evaluation.
Through the ATF perfusion process, we reached a significant peak cell density of 7.4×10 7 cells/mL and produced 11.4 g of antibody within two weeks. Compared with our batch and fed-batch processes, this represents a 12-fold and 2.5-fold increase in product output, respectively. It is twice the amount of antibody produced during ATF perfusion using a similar MAb-producing CHO cell line, and twice as much as reported elsewhere.
The choice of culture mode for production depends on budget, available time and quantity of hMAb required. Considering the use of simple equipment and processes, minimal manual intervention in just five days, and a relatively low amount of medium, simple batch culture may be the cheapest and fastest method to produce very small amounts of hMAb. Fed-batch culture can increase the yield of hMAb by five times, but for a long time, although the medium usage rate is still very low, it requires more manual intervention and more complicated equipment.
The ATF perfusion method provides the highest yield of live cells and hMAb. However, it requires additional capital investment and laboratory space for ATF filtration units and controllers, as well as operating complex equipment, collecting multiple samples per day and monitoring the volume of the container. It also uses a lot of cell culture medium. The setup of the packed bed container only needs to connect it to the control station to perform standard monitoring of the container volume, and sampling is also very simple. In addition, the peak cell density produced by this method is close to the peak density of the ATF process, but there is no additional fixed equipment or complicated operations.
The use of disposable equipment is on the rise in bioprocess development because it reduces turnaround time and the risk of cross-contamination. We have successfully used disposable containers in our batch feeding process and two perfusion culture modes. Adding an ATF filter device and using a solid growth support matrix in a packed bed container can achieve simple cell retention and higher cell and product yields. Through long-term perfusion culture, antibodies can be collected continuously for up to two or three months after a single inoculation, which can achieve higher productivity.