A novel scale‐down mimic of perfusion cell culture using sedimentation in an automated microbioreactor (SAM)

Abstract

Continuous upstream processing in mammalian cell culture for recombinant protein production holds promise to increase product yield and quality. To facilitate the design and optimization of large‐scale perfusion cultures, suitable scale‐down mimics are needed which allow high‐throughput experiments to be performed with minimal raw material requirements. Automated microbioreactors are available that mimic batch and fed‐batch processes effectively but these have not yet been adapted for perfusion cell culture. This article describes how an automated microbioreactor system (ambr15) can be used to scale‐down perfusion cell cultures using cell sedimentation as the method for cell retention. The approach accurately predicts the viable cell concentration, in the range of about 1 × 107 cells/mL for a human cell line, and cell viability of larger scale cultures using a hollow fiber based cell retention system. While it was found to underpredict cell line productivity, the method accurately predicts product quality attributes, including glycosylation profiles, from cultures performed in bioreactors with working volumes between 1 L and 1,000 L. The spent media exchange method using the ambr15 was found to predict the influence of different media formulations on large‐scale perfusion cultures in contrast to batch and chemostat experiments performed in the microbioreactor system. The described experimental setup in the microbioreactor allowed an 80‐fold reduction in cell culture media requirements, half the daily operator time, which can translate into a cost reduction of approximately 2.5‐fold compared to a similar experimental setup at bench scale.

Cell culture media for recombinant protein expression in Chinese hamster ovary (CHO) cells: History, key components, and optimization strategies

“…Concentrated media formulated for precise delivery of nutrition can facilitate the manufacturing process and reduce cost . Although perfusion experiments and processes are typically executed in bench‐scale bioreactors, inexpensive and convenient scale‐down models for perfusion have been developed in deep well plates, spin tubes, and automated bioreactors, which can enable the large statistical DoE screens required to optimize perfusion media …”

Spectroscopy integration to miniature bioreactors and large scale production bioreactors–Increasing current capabilities and model transfer

“…These systems have many benefits such as being fully automated, can operate numerous bioreactors simultaneously, can mimic many of the characteristics of larger scale bioreactors, and can be used as scale-down models. 6,7 However, at small scales (<15 ml), it can be challenging to operate them in a similar manner as large scale bioreactors due to the greater number of vessels to sample and reduced bioreactor working volume, limiting the number of offline measurements that can be taken. Furthermore, there has been a huge drive in the pharmaceutical industry to adopt process analytical technologies (PAT) as a result of the FDA PAT Initiative 8 to enhance monitoring and control of processes.…”

“…Automated, high‐throughput miniature bioreactors have been widely adopted in the industry to aid in automated screening of cell lines. These systems have many benefits such as being fully automated, can operate numerous bioreactors simultaneously, can mimic many of the characteristics of larger scale bioreactors, and can be used as scale‐down models 6,7 . However, at small scales (<15 ml), it can be challenging to operate them in a similar manner as large scale bioreactors due to the greater number of vessels to sample and reduced bioreactor working volume, limiting the number of offline measurements that can be taken.…”

Bioprocess considerations for T‐cell therapy: Investigating the impact of agitation, dissolved oxygen, and pH on T‐cell expansion and differentiation

“…Furthermore, a translation of the perfusion‐mimic procedure may not be feasible at the large scale. At scale, additional cell separation equipment based on either spinning membrane filtration, alternating tangential flow, or acoustic separation could be employed in conjunction with the bioreactors, as scalability of the perfusion‐mimic procedure has been demonstrated previously (Kelly et al, 2018; Klarer, Marsh, Ranade, & Smith, 2017; Kreye et al, 2019; Sewell et al, 2019).…”