The main advantages of using the perfusion system are ease of use, scalability, and cost. [1] First, perfusion bioreactors are typically smaller in size compared to other forms of bioreactors yet produce the same product yield. For example a 50L perfusion bioreactor can produce the same amount of product as a 1,000L fed-batch bioreactor.5 Furthermore, due to the intrinsic nature of creating a system that maintains constant chemical conditions, cells can continuously grow without the need of constantly passaging cells and replacing media - thus it is less labor intensive. The next advantage is scalability. Due to the smaller size of perfusion bioreactors, less labor intensive, and ease of operation, perfusion systems can be scaled by adding more reactors to the system. This does not drastically require more man power or occupies more space. Lastly, since a 50L perfusion bioreactor can produce the same amount of product as a 1000L fed-batch bioreactor, it is more cost effective. As a result, perfusion bioreactors can be advantageous regarding cost savings.
Typical CSTRs follow this similar growth pattern shown on the left. Once the cells are confluent and steady state flow is maintained, the cell density remains constant with time. Furthermore, feed stock and waste concentrations remain constant since the influx and efflux remain constant [2].
Key Assumptions:
Constant Volume (dV/dt = 0)
Constant Flow Rate (F_in = F_out & dF/dt = 0)
No initial product (Po = 0)
Monod Kinetics
Negligable endogenous metabolism (kd =0)
The perfusion bioreactor on the left cultivates a 3D cell culture by using polycarbonate chambers and a multichannel peristaltic pump.
The image is of WuXi Biologics' perfusion processing of cell cultures.
“Hybrid System Aims to Streamline Cell Culture.” GEN - Genetic Engineering and Biotechnology News, 1 May 2010, https://www.genengnews.com/magazine/133/hybrid-system-aims-to-streamline-cell-culture/.
Perfusion – Making the Most out of Your Working Volume - Eppendorf Handling Solutions. https://handling-solutions.eppendorf.com/cell-handling/bioprocess/processes-and-applications/detailview/news/perfusion-making-the-most-out-of-your-working-volume/. Accessed 19 May 2020.
3D Perfusion Bioreactor System [3DB-10] : Zen Cart!, The Art of E-Commerce. http://www.3dbiotekstore.com/index.php?main_page=product_info&cPath=16&products_id=129. Accessed 14 May 2020.
4 - Pharmaceutical Technology. https://www.pharmaceutical-technology.com/projects/wuxi-biologics-perfusion-biologics-manufacturing-facility-wuxi-city/attachment/wuxi-biologics-perfusion-biologics-manufacturing-facility-wuxi-city4/. Accessed 19 May 2020.