Mammalian cell damage in a novel membrane bioreactor

Abstract

The experimental study has assessed a novel membrane bioreactor for mammalian cell culture. In the absence of a gas phase, the key features of cell damage associated with laminar and turbulent flow have been identified. The bioreactor employs a dimpled membrane in order to enhance transverse mixing in a narrow channel, but a fall in viable cell density has been observed at Reynolds numbers above Re = 83. In the laminar flow regime wall shear is the critical mechanism and an accurate calculation of shear rate in a complex channel has been achieved using the Reynolds analogy. Flow generating a wall shear rate in excess of 3000 s(-1) has been shown to cause damage. Power dissipation measurements have been used to distinguish between laminar and turbulent flow and also to predict Kolmogorov eddy lengths. An additional turbulent bulk stress damage mechanism at higher Reynolds numbers (Re > 250) results in a very rapid fall in viable cell density.

Collagen matrix deposition is dramatically enhanced in vitro when crowded with charged macromolecules: The biological relevance of the excluded volume effect

“…Therefore, the application of EVE is an important tool in creating greater and more confluent ECM coverage of the supporting material. This is particularly important for the 3-D bioreactor setting, where flow rates and scaffold design can generate strong local shear forces which detach cells [19,20]. To attain suitable seeding rates onto scaffolds, incubations are usually first performed under static culture conditions for several days [21,22].…”

Hydromechanical stimulation of bioluminescent plankton

“…The analysis of a flow that interacts with suspended material is important in many industrial and engineering applications: formation and break-up of flocs (1,2), growth of biofilms (3), cell damage (4,5), etc. Bioluminescent dinoflagellates comprise part of the marine plankton and have the remarkable ability to emit visible light (6,7).…”

2‐Chlorobenzoate Biodegradation by Recombinant Burkholderia cepacia under Hypoxic Conditions in a Membrane Bioreactor

“…Many studies have reported on the impacts of shear stress on MBR performance. These include morphological alterations in bacteria, decrease in cell activity and viability, considerable shift in microbial community dynamics, release of extracellular and fine colloidal compounds, and decline in permeability (Brockmann and Seyfried, 1996;Klatt and LaPara, 2003;Millward and Bellhouse, 1994;Shimuzu et al, 1996). Figure 6 shows the size distribution of B. cepacia strain DNT floc size before recirculation through the membrane filter unit and after 156 days of MBR operation.…”