Partial and Total Cell Retention in a Filtration‐Based Homogeneous Perfusion Reactor

Abstract

Suspended mammalian cells can be cultivated in a variety of operational modes (pure chemostat, total cell retention, or partial cell retention) in a homogeneous perfusion bioreactor by varying the cell bleed rate. Hybridomas were grown in the reactor at a perfusion rate of 2.0 day-1 for over 10 weeks at different specific growth rates and viable cell densities achieved by varying the extent of cell retention. Cell metabolism in the reactor was found to vary with the extent of cell retention, which determined both cell density and specific growth rate. With partial cell retention, the nutrient consumption and metabolite production rates decreased with both increasing growth rate and increasing cell density. The specific and volumetric antibody production rates, however, increased dramatically with cell density (and to a lesser extent with decreasing growth rate). The specific MAb production rate was lower with total cell retention than with partial retention at the same growth rate. Since the reactor can be operated over a range of perfusion rates and extents of cell retention, the system can be used to culture cell lines with widely different productivity patterns.

Comparison of Batch and Perfusion Culture in Combination with Pilot‐Scale Expanded Bed Purification for the Production of Soluble Recombinant β‐Secretase

“…Perfusion offers a number of advantages over batch cultivation, such as increased volumetric productivity. Perfusion cultures using suspension cells operated under conditions of total or partial cell retention have been characterized as being homogeneous (18)(19)(20). One of the key operating parameters using perfusion is the rate of medium replacement.…”

In situ cell retention of a CHO culture by a reverse‐flow diafiltration membrane bioreactor

“…Cultures were incubated in 50 mL disposable bioreactors (TPP, Trasadingen, Switzerland) with a working volume of 10 mL at 180 rpm, 37 C, 5% CO 2 in a K€ uhner ISF1-C-CO 2 incubator (K€ uhner AG, Basel, Switzerland). Pre-cultures used for inoculation of the perfusion bioreactor were cultivated accordingly but in disposable 500 mL Erlenmeyer shake flasks (Sigma Aldrich Chemie GmbH, Steinheim, Germany), and typically reached cell densities of 1 3 10 6 cells mL 21 .…”

“…The set-point of the dissolved oxygen tension (DOT) was 40% and maintained by pulsed aeration. The bioreactor was inoculated with a cell density of 1 3 10 5 cells mL 21 .…”

“…Separation by means of size exclusion is conducted most often using filtration. State of the art technologies are hollow-fiber modules, 21,22 cross-flow filtration devices [23][24][25] and rotating or spin-filters. 26,27 The most recent studies in the literature often apply the ATF module (Alternating tangential flow technology), which is commercially available in several scales.…”

Kinetics independent multivariable robust control of animal cell cultures

“…Among them, operation in perfusion mode leads to higher cells density and higher productivity [2]. However, it requires also tight control to avoid nutrient limitation, accumulation of inhibitory metabolites, retardation in cells growth or even cells wash-out through the cell-containing flow (the bleed), which is necessary to maintain culture viability and to reach a steady state [3], [4], [5].…”