A fundamental study of Starling flow and protein redistribution within a cell-free rectilinear membrane flow device.

The efficiency of hollow fiber bioreactors depends on design and operations parameters. Protein redistribution, a consequence of Starling flow, can result in poor cell distribution and reductions in performance. Hydrodynamic investigations require consideration of design and sampling. A simplified rectilinear flow system was developed and modeled. A 2D (SIMPLER) model incorporating gravity, and correlations for density, viscosity, diffusivities, and osmotic pressures was coded in FORTRAN 77. Experiments with bovine serum albumin (BSA) and a cellulose acetate membrane were carried out to validate the model. Further validation was obtained with a 1D simulator. Simulations show the effects of run duration, initial BSA concentration, channel velocity, and Dextran 70 loading on BSA polarization. The results indicate noticeable BSA polarization only in long duration runs, BSA redistribution in the transverse direction, and the importance of buoyancy. Simulations with fluid flowing against gravity suggest that this orientation can be used to eliminate protein polarization