Crossflow microfiltration of animal cells

Abstract

Laminar shear is the primary mechanism of cell damage, limiting flow rate (and hence flux) in crossflow microfiltration of animal cells. Sensitivity to hydrodynamic and interfacial stress is reduced by the addition of 0.1% Pluronic polyol. A critical average wall shear rate of 3000 s(-1) (above which damage occurs) is found for several cell types, including mammalian and insect cells. Hydrodynamic stress also limits the maximum tip speed in a rotary lobe pump to less than 350 cm/s. Turbulent flow in the recirculation loop piping at Reynolds numbers of up to 71,000 does not cause cell damage. Maximum sustainable flux decreases with cell concentration and increases with cell size (in qualitative agreement with the hydrodynamic lift model). A flux of 30 to 75 L/m(2) h (depending on cell size) can be sustained during 20-fold concentration from 2.5 x 10(6) cells/ml, while maintaining high cell viability.

Rapid Sample Processing for Detection of Food-Borne Pathogens via Cross-Flow Microfiltration

“…The surfactant lowers the interfacial tension between the membrane surface and the attached cells and hence enhances their recovery. The possibility that microfiltration may damage cells due to stress induced by the laminar shear field or by deformation of the cell in filter pores under the transmembrane pressure was also examined in our work (30). The extent of shear damage depends on the intensity, duration, and type of shear force and also on the cell type and growth stage (31).…”

Mammalian cell retention devices for stirred perfusion bioreactors

“…Maiorella et al (1991) reported that cells were damaged at wall shear rates over 6000 s −1 , while Zhang et al (1993) observed a drop in culture viability at a shear rate of 1300 s −1 during perfusion using a hollow-fiber cartridge. Higher shear rates require higher inlet pressures and thus also increase the transmembrane pressure difference at the filter inlet.…”

Optimal feeding strategy of diafiltration buffer in batch membrane processes

“…The improvement for more complex scenarios can be significant enough to invest in better models and advanced control configuration. 3 where ith order time derivatives will be considered with i = {1, 2, . .…”

“…Consider now a case where we want to arrive at final point [5,3.97] (square in Fig. 4) starting from the same initial point.…”

“…These are normally preferred when unfavourable effects such as enhanced fouling or product quality deterioration are associated with high concentration of retained species at the membrane wall. For instance, when animal cell damage [3] or denaturation/adsorption of high-value protein pharmaceuticals [4] are of major concern. The work presented here examines the constant pressure approach.…”