Cell-free expression (CFE) is the practice of making a protein without using a living cell. In contrast with cell line-based methods, production is achieved using a fluid containing biological components extracted from a cell, i.e., a lysate. CFE offers potential advantages for biopharma according to Philip Probert, PhD, a senior scientist at the Centre for Process Innovation in the U.K.
“CFE has been in use in academia for decades but is only now gaining traction as a means of biologics production,” he said, adding “The biopharmaceutical industry needs more agile manufacturing methods that are better suited to the production of a greater diversity of therapeutics. Using cell-free rather than conventional cell-based manufacturing minimizes process development requirements and can also be used to express multiple products within a short timeframe. An additional advantage is that in contrast with conventional expression systems, CFE requires minimal manufacturing infrastructure.”
Because the reactions can be scaled up it is possible to imagine CFE could be used for local manufacture of stratified treatments on demand, which could not be easily achieved with cell-based expression due to the infrastructure associated with culturing live cells, according to Probert.
CFE has been a mainstay of the research lab for decades. However, until recently the complexity of making the lysate, and ensuring it is consistent, made it hard to use for commercial-scale biopharmaceutical production. “Following fermentation, traditional lysate generation processes use multiple wash steps, and freeze-thaw or sonication for lysis, but these are not practical at commercial scale and can introduce variability into the final product,” he explained.
But the situation has changed, according to Probert, who says he has developed a scalable and robust lysate generation process.
“We designed a process with the minimal required steps that is straightforward to scale and transfer, and for which we could generate quality parameters to benchmark performance between batches,” he said. “The lysate generation process involves growing the cells up in a fermenter, followed by cell lysis, clarification and subsequent processing to generate a consistent lysate for CFE.”
As a result, there is real potential for CFE in industrial biopharmaceutical manufacturing, maintains Probert, citing personalized medicine as an example. “With increasing interest, it is likely that overtime we may start to see CFE increasingly considered as a means of manufacture for the next generation of personalized biotherapeutics.”