Better Antibody Production using FiberCell Systems CDM-HD (Chemically Defined High Density Serum Replacement) and Hollow Fiber Bioreactor
FiberCell Systems vs. Flask vs. Wave Bag
Hollow Fiber cell culture is the ideal method for the production and collection of secreted products from mammalian cells. A large numbers of cells can be supported in a small space and the secreted product is highly concentrated. The high surface area to volume ratio that hollow fiber bioreactors provide (100cm2/ml or more) and the extreme high flux rates of fibers from FiberCell Systems can allow cells to grow at 100X
the density found in ﬂask culture (108 vs. 106/ml). The FiberCell Systems hollow fiber bioreactor system is one of the only cell culture methods that permit cell cultures at densities similar to those found in-vivo. High cell density allows cells to be grown in reduced serum environments (as low as 2% vs. 10% for conventional culture methods) and more easily adapted to commercially available serum free mediums. However, commercial serum free mediums are expensive and can sometimes be optimal for only a limited number of cell types. The concept of CDM-HD is simple: produce a serum substitute that can take advantage of the simplified serum requirements for cells grown at high density in hollow fiber bioreactor systems. CDM-HD represents a true breakthrough in cell culture technology. It is the ﬁrst time that a speciﬁc culture medium takes advantage of growth conditions to simplify and optimize the medium for those conditions.
CDM-HD Serum Replacement is a chemically deﬁned, protein free serum replacement that permits any basal medium such as DMEM to be used without serum. CDM-HD is designed speciﬁcally for the culture of cells at high density and
optimized for use in hollow ﬁber bioreactor systems.
Secreted products such as monoclonal antibodies and recombinant proteins are free of contaminating proteins from the medium. The harvest can be puriﬁed using simpliﬁed protocols, increasing net yield in many cases. CDM-HD provides lot-to-lot consistency and is an economical replacement for serum. It is available as a dry powder to make up one liter and is used at a concentration of 10%.
To demonstrate the utility of CDM-HD, a direct comparison was performed between monoclonal antibody production from the same standard murine SP2 clone in a 20 liter wave bag containing 10 liters of medium, T175 tissue culture flasks (1.2 liters consumed, data normalized to 10 liters for comparison) and a FiberCell Systems C2011 medium 20kd MWCO hollow fiber bioreactor cartridge, set up according to the manufacturer’s protocol and allowed to consume 10 liters of medium. Flask data and Wave bag data were generated using a commercially available serum free hybridoma medium (SFM), while FiberCell Systems data was generated using DMEM medium with 10% CDM-HD chemically defined serum replacement. Total protein was measured before and after Protein A purification and antibody quantitation performed on column eluent.
Figure one: Purified antibody and ratio of antibody to total protein for the three systems. Flask culture yielded almost as much antibody as the FiberCell Systems cartridge, however the antibody in the FiberCell Systems harvests is about 50X more concentrated. Note the large amount of extra protein from the wave bag, probably due to cell lysis. Non-antibody protein in the flask is from the serum free media, which is not protein free. FiberCell Systems culture when used with CDM-HD is free from exogenous protein and cell lysis.
Figure two: Antibody yield per 10 liters of medium consumed, total harvested antibody concentration prior to purification. Note the extremely high concentration of antibody in the Fibercell Systems hollow fiber bioreactor cartridge. 200mls of harvested supernatant was equivalent to 10 liters of culture supernatant from the other systems again reflecting the 50X higher concentration of antibody generated in the FiberCell Systems bioreactor cartridge.
These data represents a direct comparison between a Wave bioreactor bag, standard T175 tissue culture flasks and a medium sized FiberCell Systems C2011 hollow fiber bioreactor cartridge. The FiberCell Systems cartridge produced 6 times the amount of antibody than the Wave bag produced at 50 times higher concentration with no exogenous protein. The FiberCell Systems cartridge produced slightly more antibody than the T175 flasks but at a concentration 50X higher with no detectable exogenous protein. CDM-HD is optimized for higher density cell culture, and therefore the media employed in this comparison were not identical. The comparison demonstrates the power of the combination of hollow fiber bioreactors and a medium designed to take advantage of this higher cell density. It should also be noted that the Wave bag is a 1-2 week batch mode process, while the FiberCell Systems cartridge can be maintained producing antibody for more than 6 months if so desired, further increasing amount of antibody produced per reactor cycle or annum.
From a separate experiment the gel below shows the composition of harvests from the FiberCell Systems hollow fiber bioreactor cartridge when using DMEM with 10% FBS and then switched to DMEM with 10% CDM-HD. The secreted antibody is almost the only protein present allowing for a simplification of the purification protocol.
Photo demonstrates the high cell density that is seen in a FiberCell Systems hollow fiber bioreactor cartridge.
All data was generated by an independent research facility.
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