4.4.5 Rocking bioreactor design
Turbulent flows and shear forces can induce spontaneous generation of stem cells [41], so reactor configurations which produce less of these forces are of interest in cultivated meat production. Wave bioreactors, designed to provide excellent mixing and gas transfer with reduced shear stress, are well-suited to the culture of cells highly sensitive to hydrodynamic conditions. These systems consist of a bag on a rocking tray that agitates the cell culture with a back and forward wave-like movement, and they are available at working volumes up to 500 L [42]. Computational fluid dynamic modeling approaches have been applied to study fluid flow within wave bioreactor designs, with a focus on an improved understanding of the effects of agitation and rocking angle [42]. Interestingly, in their work, Zhan et al. [42] found that the lowest rocking speed (15 rpm vs. 22 and 30 rpm) produced the highest fluid velocity, mixing and shear forces due to a resonance phenomenon. We intend to use these techniques coupled with other approaches to inform a biological model, describing what happens to the cells, how their proliferation is slowed or how apoptosis is induced for some due to the forces they endure. These novel models should be particularly useful to assess the suitability of a rocking bioreactor design from Celltainer Biotech BVwhich has been promoted for use in cultivated meat production.