Challenges and opportunities in downstream separation processes for mesenchymal stromal cells cultured in microcarrier‐based stirred suspension bioreactors

Abstract

Mesenchymal stromal cells (MSC) are a promising platform for regenerative medicine applications because of their multilineage differentiation abilities and ease of collection, isolation, and growth ex vivo. To meet the demand for clinical applications, large-scale manufacturing will be required using three-dimensional culture platforms in vessels such as stirred suspension bioreactors. As MSCs are an adherent cell type, microcarriers are added to the culture to increase the available surface area for attachment and growth. Although extensive research has been performed on efficiently culturing MSCs using microcarriers, challenges persist in downstream processing, including harvesting, filtration, and volume reduction, which all play a critical role in the translation of cell therapies to the clinic. The objective of this review is to assess the current state of downstream technologies available for microcarrier-based MSC cultures. This includes a review of current research within the three stages: harvesting, filtration, and volume reduction. Using this information, a downstream process for MSCs is proposed, which can be applied to a wide range of applications.

Optimized operation of a controlled stirred tank reactor system for the production of mesenchymal stromal cells and their extracellular vesicles

“…To support all these clinical applications, large doses of EVs will be required and the limited manufacture capacity of traditional static culture systems will be a major hurdle toward the implementation of EVs‐based therapies. In this context, the large‐scale production of therapeutic MSC and their EVs will require the development of a cost‐effective manufacturing platform based on fully controlled bioreactor systems for the expansion of well‐characterized MSC populations and the production of their MSC‐CM, as well as a robust downstream process to isolate and purify MSC and MSC‐EVs (reviewed in Mawji et al [2022] and Syromiatnikova et al [2022]). In this work, an S/X‐free microcarrier‐based culture system was successfully established for the expansion of MSC(M) and the production of MSC‐EV using a 2 l ‐scale controlled STR as it represents a scalable, robust, cost‐effective, and well‐characterized platform widely used to produce biotherapeutics.…”

“…this context, the large-scale production of therapeutic MSC and their EVs will require the development of a cost-effective manufacturing platform based on fully controlled bioreactor systems for the expansion of well-characterized MSC populations and the production of their MSC-CM, as well as a robust downstream process to isolate and purify MSC and MSC-EVs (reviewed inMawji et al [2022] andSyromiatnikova et al [2022]). In this work, an S/X-free microcarrier-F I G U R E 2 Characterization of human mesenchymal stromal cell (MSC)-derived extracellular vesicles (EVs) produced in a fully-controlled stirred tank reactor (STR) operated under fed-batch (FB) or fed-batch combined with continuous perfusion (FB/CP) operation mode.…”

A Multi-Stage Bioprocess for the Expansion of Rodent Skin-Derived Schwann Cells in Computer-Controlled Bioreactors

“…The greatest losses occurred when detaching the cells from the microcarriers and separating the cells from the microcarriers. Recently, a number of responsive microcarriers have been investigated that respond to stimuli like pH and temperature, or enzymatically dissolve [ 35 ]. These microcarriers aim to limit the exposure of cells to potentially harmful harvesting enzymes through modifications to the microcarrier during the harvesting step as opposed to the cells themselves [ 36 ].…”

Optimized operation of a controlled stirred tank reactor system for the production of mesenchymal stromal cells and their extracellular vesicles

“…To support all these clinical applications, large doses of EVs will be required and the limited manufacture capacity of traditional static culture systems will be a major hurdle towards the implementation of EVs-based therapies. In this context, the large-scale production of therapeutic MSC and their EVs will require the development of a cost-effective manufacturing platform based on fully controlled bioreactor systems for the expansion of well-characterized MSC populations and the production of their MSC-CM, as well as a robust downstream process to isolate and purify MSC and MSC-EVs [reviewed in (Mawji et al, 2022;Syromiatnikova et al, 2022)]. In this work, a S/X-free microcarrier-based culture system was successfully established for the expansion of MSC(M) and the production of MSC-EV using a 2 L-scale controlled STR as it represents a scalable, robust, cost-effective, and well-characterized platform widely used to produce biotherapeutics.…”