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

Recent advances in stem cell research and regenerative medicine are leading towards the realistic commercial prospect of more complex cell-based therapeutic products, offering the potential to revolutionize aspects of healthcare system. To date however, there are no truly ‘large-scale’ cell therapy products available. To achieve successful commercial production, many factors come into play. To name a few; economics, robustness, reproducibility and, what this review is concerned about: scalability. With cell therapies, a change in the processing environment may lead to a product change, which ultimately may be the difference between a successful batch (meeting product specifications) or a failed one [1]. To minimize process changes throughout the scales, processing steps must be carefully selected from an early stage. A particular challenge faced is that current ‘gold standard’ techniques for cell separation are not generally compatible with large scale processes. Dead-end batch centrifugation is a clear example of a process step that is heavily manual, difficult to automate while maintaining sterility, and limited in scalability [1]. The scope of this article is to explore and evaluate current and potential future techniques for cell separation at large scale only.