The Mobius CellReady family of products includes the bench-scale (3-L), small-scale (50-L) and pilot-scale (200-L) bioreactor
systems that enable cell growth in volumes appropriate for early process development through clinical batch production. The
small-scale Mobius CellReady 3-L bioreactor is a rigid, stirred-tank bioreactor (see Figure 1A) while the Mobius CellReady 50-L and 200-L bioreactor systems (see Figures 1B and 1C) are inflatable stirred-tank bioreactor process containers used in stainless-steel vessels. Table I outlines the features of all three. Both the Mobius CellReady 50-L and 200-L bioreactor process containers use the Mobius
SensorReady technology for process monitoring and control. The Mobius SensorReady assembly is an external loop that is connected
to the bioreactor process container that allows for a configurable number of probes and sensors to be used.
Figure 1: (A) 3-L Mobius CellReady bioreactor; (B) 50-L; and (C) 200-L Mobius CellReady bioreactor process containers.
The ability to scale up a biomanufacturing process is essential for process development and the production of biologics. Bioreactor
process set points, acceptable ranges, and general operating parameters used at the large scale are commonly based on those
developed at the benchtop or small scale where experimentation is more cost effective and efficient. Large-scale performance
and production expectations are often established based on results obtained at smaller scales. It is, therefore, important
that the process parameters developed at the small scale are readily transferrable to the larger scale.
Table I: Comparison of the features of 3-L, 50-L, and 200-L CellReady bioreactors.
Challenges to bioreactor scale-up occur because even when two geometrically similar tanks are used, it is not possible to
simultaneously maintain key bioreactor characteristics such as shear, mixing time, and oxygen mass transfer coefficient (kLa) identical in both the large and small tanks (1). Other variables, such as bubble size and distribution, nutrient regulation
and delivery, and process control capabilities may also contribute to variable performance results across scales. Ultimately,
successful scale-up is determined when comparable process performance endpoints such as cell growth, cell viability, protein
production, and product quality are achieved. The probability of meeting these criteria can be increased when the bioreactor
systems are well-characterized and the process design space is better understood.
In this study, several key engineering parameters kLa, power-per-unit volume, Reynolds number (Re), mixing time, and tip speed were characterized for the three different sized
single-use bioreactor process containers. Chinese hamster ovary (CHO) cells were then cultured in each of these bioreactor
systems based on maintaining equivalent power per unit volume as the primary scaling parameter. The results of this study
define the characterization and process design space offered by the bioreactor systems and demonstrates the capability to
achieve expected cell culture performance results across scales, thus demonstrating the scalability of the family of Mobius
CellReady bioreactor systems.