A new cell culture method for adherent cells—touted as a continuous upstream manufacturing technique suited specifically for cell-based therapies—was recently announced. The technique relies on a special coating applied to surfaces where adherent cells attach. The Newcastle University study describing the approach was published in ACS Applied Materials & Interfaces.
The coating is said to be capable of controlling the attachment and proliferation of cells, and it reportedly also allows the cells (in this case, human corneal stromal cells) to self-detach from culture. This is a departure from current cell-detachment methods, wherein cells are typically removed from a growth surface with the help of chemicals.
Because the cells grow in a sheet and slough away from the surface independently, surface area for a new layer of cells to form is continuously available. GEN spoke to John Bonham-Carter (who was not involved with the study), director of upstream sales and business development at Repligen, to discover what types of cells could benefit from such an innovation and see how this new method of continuous cell detachment compares to current methods of cell culture.
Is the technique described really novel?
Yes, it is novel in my view; it’s kind of [like] a reverse printing roller technique. Everyone else (I know of) is looking at cell cubes and other, multilayer scale-out [for cell culture].
Is the technique described only relevant to adherent cells?
So, this is the crux of the issue—absolutely everyone would prefer to get away from adherent cells because the current production techniques aren’t scalable. So, continuing the parallel, rather than automate with a reverse printing technique, others are trying to go straight to 3D growth, either in scaffolds for tissue culture that are directly implantable (which assumes structure is key to function) or in traditional stirred-tank bioreactors (which are the gold standard of cell culture).
How would this new biomanufacturing strategy best be used (i.e., for what kinds of products)?
The technique looks ideal for growing skin cells and other 2D, or near-2D, products where sheets of cells can be utilized directly, perhaps with multiple layers employed. However, getting 1 billion cells in a meter square is impressive next to a football pitch comparison, but not compared to current Chinese hamster ovary (CHO) cell standards of 100–200 million cells/mL prior to concentration—a 10-mL to 50-mL reactor with suspension cells grown in perfusion would still be preferable. With stem cells being around 10+ times less concentrated than CHO cells, many liters are still required, plus the cells may need direction differentiating, depending on final function. Yet, in terms of bulk processing, suspension cell culture is still the most homogeneous and controlled environment we have. This engineering fact drives most labs today.