Bioprocessing And Scaleup Of HEK293 Cells For AAV Production

By Eva Fong (Principal Scientist, MilliporeSigma, Carlsbad, CA), Andi Ushijima (Scientist, MilliporeSigma, Carlsbad, CA), and Henry George (Head of Viral Vector Producing Cell Lines, MilliporeSigma, St. Louis, MO)

Adherent cell culture production processes can pose challenges to the safety and quality of the vector.  One challenge is that it utilizes tissue culture flasks, CellStack®️ devices, or roller bottles, which can limit scale due to a small amount of surface area or facility area. The process usually requires multiple rounds of manual handling and manipulation of cell cultures within a biosafety cabinet, increasing the risk of contaminants due to the open processing. Another challenge when producing AAV is there are many serotypes with unique tropisms from which to choose. Each serotype has its own biology; some serotypes require high production volumes and produce low vector yields. Finally, viral particles that do not contain packaged genetic material (i.e., empty capsids) are also produced during this process; this is a challenge as the empty capsids can reduce the efficacy of the final drug product. Therefore, alternative methods for cell culturing are necessary to meet today’s viral vector demand.

A suspension culture system, where cells grow suspended in a liquid medium, offers a viable alternative, as the process can be scaled to larger batches while also yielding significantly higher doses per single batch. A major benefit of suspension culture is the ability to grow the cells in a chemically defined, animal component-free medium, thereby removing animal containing components, which reduces safety risks and overall process variability. The VirusExpress®️ 293 AAV production platform helps provide a solution to the common challenges of traditional adherent cell culture by providing a scalable, suspension cell culture process utilizing a simplified upstream process with chemically defined animal component-free cell culture media. Download the full article to find out how the established production process can help reduce manufacturing risk and speed to the clinic.