An ultra scale‐down methodology to characterize aspects of the response of human cells to processing by membrane separation operations

Abstract

Tools that allow cost‐effective screening of the susceptibility of cell lines to operating conditions which may apply during full scale processing are central to the rapid development of robust processes for cell‐based therapies. In this paper, an ultra scale‐down (USD) device has been developed for the characterization of the response of a human cell line to membrane‐based processing, using just a small quantity of cells that is often all that is available at the early discovery stage. The cell line used to develop the measurements was a clinically relevant human fibroblast cell line. The impact was evaluated by cell damage on completion of membrane processing as assessed by trypan blue exclusion and release of intracellular lactate dehydrogenase (LDH). Similar insight was gained from both methods and this allowed the extension of the use of the LDH measurements to examine cell damage as it occurs during processing by a combination of LDH appearance in the permeate and mass balancing of the overall operation. Transmission of LDH was investigated with time of operation and for the two disc speeds investigated (6,000 and 10,000 rpm or ϵ max ≈ 1.9 and 13.5 W mL−1, respectively). As expected, increased energy dissipation rate led to increased transmission as well as significant increases in rate and extent of cell damage. The method developed can be used to test the impact of varying operating conditions and cell lines on cell damage and morphological changes. Biotechnol. Bioeng. 2017;114: 1241–1251. © 2017 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc.

Bioprocess engineering strategies for autologous human MSC-based therapies: one size does not fit all

“…The impact of such shear magnitudes on cells destined for cell therapy has been carried out in small (µL) volumes [69,70] showing that fluid flow conditions could be fine-tuned to minimizing cell loss and cell property degeneration. Scale down strategies aiming to mimic the effects of specific downstream processes were also recently shown by Delahaye et al [71] for dead-end centrifugation, and by Masri et al [72] for a membrane separation and recovery bioprocess. We could therefore suggest that such scale down tools could provide a first solid basis for evaluating optimal bioprocess integration scenario at a low cost and low risk environment.…”

Challenges and advances in scale-up of label-free downstream processing for allogeneic cell therapies

“…Both scenarios present challenges for traditional downstream processing systems. Processing 200 L of cells with current technologies can take hours, compromising cell health by holding the cells priorand post-processing which can lead to increased cell death [4]. Processing a smaller volume with very high cell density (i.e., highly viscous cell suspension) will inevitably be harder to handle.…”

An ultra scale‐down method to investigate monoclonal antibody processing during tangential flow filtration using ultrafiltration membranes

“…This latter form of the USD device allows the flow over the membrane to be varied independently of the transmembrane flux or pressure. It has been used to study microfiltration for antibody fragment recovery from clarified Escherichia coli lysates (Ma et al, ) and human cell recovery (Masri, Lawrence, Wall, & Hoare, ). This article addresses the challenge of characterizing the shear rate over the membrane in such a way that it can be related to shear rate in full‐scale operations.…”