Extracellular vesicles (EV) from many cell types have demonstrated therapeutic potential against many different diseases. Inhibiting progress in this area is the capability to produce EVs in sufficient quantity to deploy them in in vivo research applications and ultimately the clinic. Current methods can utilize large numbers of flasks and serum starvation in a batch mode process, or large volume conventional bioreactor systems. It is clear that culture conditions affect the concentration, composition and therapeutic activity of secreted extracellular vesicles. 3-D capillary bioreactors represent the most in vivo like way to culture cells. They can support the culture of large numbers of cells at high densities, 1-2X10e8 cells/ml, 2X10e10 total cells. Cells are bound to a porous support with a 20kDa molecular weight cut off (MWCO) so cell passaging is not required and EVs cannot cross the fiber in either direction. Secreted EVs are concentrated, free from contaminating serum EVs, show reduced membrane fragment contamination and in some cases have demonstrated enhanced bioactivity. The functional principles of 3-D capillary bioreactors will be shown, and examples of the current and potential future of clinical EV scale-up will be discussed.
1. What are the three fundamental differences between a 3-D hollow fiber bioreactor and a T flask?
2. What is the definition of a Dalton?
3. In what ways is a 3-d hollow fiber bioreactor more in vivo like?