A New Era in Cell Culture Media Development - Cell-line specific complex media supplements combine complex or chemically defined, animal-component free media additives into a single homogeneous functi

ADVERTISEMENT

A New Era in Cell Culture Media Development
Cell-line specific complex media supplements combine complex or chemically defined, animal-component free media additives into a single homogeneous functional supplement.


BioPharm International
Volume 25, Issue 7, pp. 28-35

PROCESS PERFORMANCE AND MEDIA COMPONENTS INTERACTION

The initial cause for the shift away from serum in cell-culture processes was because of its complexity and ill-defined composition. Manufacturers had to struggle with inconsistent process performance, which ultimately affected product quality.

The development of CDM containing complex component formulations has meant cell viability, cell growth, and good product titer can be maintained without the use of serum. CDM provides many benefits for the manufacture of biotherapeutics, not the least of which are regulatory compliance, simplified downstream processing, and consistency of both processes and products. Although CDM can be costly, these performance benefits are important in driving improved manufacturing processes and therefore drug-development costs down.

As the understanding for specific nutrient requirements for various production cell lines increases, media formulations are being developed to achieve optimal performance. To enhance culture performance, CDM is often supplemented with defined feeds and supplements at predetermined stages in the growth and productivity cycle. However, optimization of these strategies can be time-consuming and success of this strategy is often dependant on the basal medium formulation.

Hydrolysates, a common cell culture supplement and feed, share a number of components with CDM. The additional availability of these common media components to the cell can have an additive effect, stimulating cell growth and productivity. Alternatively, the additive effect may have a negative impact on cell performance as a result of unintentional overdosing of certain components.


Figure 3: Supplementing two commercial chemially defined media (CDM) at 100% and 80% strength with 8g/L cotton seed hydrolysate (CSH) resulted in enhanced Chinese hamster ovary (CHO) cell viability (a and c) and productivity (b and d).
To demonstrate the interaction of basal media components and supplements on biological systems, CHOK1 cells expressing a recombinant protein, were cultured in two independently sourced CDM at full strength and 80% strength, either alone or supplemented with plant-derived protein hydrolysate. The results showed supplementation of chemically defined media with plant-derived protein hydrolysates affected cell culture performance in a medium-dependent manner. Interestingly, supplementation with hydrolysate of diluted CDM achieved equivalent or enhanced cell culture performance compared with full strength supplemented CDM (see Figure 3).

COMBINATIONS OF SUPPLEMENTS AND CELL GROWTH

Cell culture media for the production of biologicals are becoming more complex. As described above, the addition of media feeds and supplements to enhance cell culture performance must be carefully matched with the basal media because of component interactions.

With the nutritional requirements for individual production cell lines and clones becoming better understood, the response to culture media and supplements must be examined in a case-by-case basis. With the implementation of design of experiment and high throughput screening of media components it is becoming increasingly possible to design and optimize supplements and feeding strategies that address the specific nutrient requirements for each cell line and clone.


Figure 4: Addition of the yeast extract and human serum albumin (HSA) supplements both alone and in combination enhanced total Chinese hamster ovary (CHO) cell density, which significantly affected product titer.
Addition of certain supplements in combination has recently been shown to have a positive effect on specific cell growth and productivity. An example of cell culture supplement interaction having a positive effect of cell performance has been observed when ultrafiltered yeast extract and recombinant human serum albumin (rHSA) were co-supplemented in CHO CDM. The ultrafiltered yeast extract, a consistent animal-free hydrolysate, at 1 g/L in combination with rHSA 1 g/L were shown to have a positive effect on growth and productivity when added alone compared with the CDM control. Moreover, when these supplements were added in combination, a synergistic response was observed for both CHO cell growth and productivity (see Figure 4).


Figure 5: Chinese hamster ovary (CHO) cell response to supplementing with yeast extract (YE) was shown to be dependant on background media. In contrast, cell performance was consistently improved when supplementing with the optimized dosage of yeast extract (YE) and human serum albumin (HSA). CDM is chemically defined medium.
Interaction of media components and the importance of optimizing supplement and feed addition according to the basal or platform media employed were further investigated. A single CHO clone was tested in two independent CDM supplemented with a range of concentrations of ultrafiltered yeast hydrolysate and an optimized dosage of ultrafiltered yeast hydrolysate (YE) and rHSA. In CDM–A, CHO cell growth decreased with increasing hydrolysate concentration while product titer and specific productivity (Qp) increased. The optimized combination of YE and rHSA demonstrated the greatest overall performance benefit (see Figures 5a and 5b). In contrast, addition of YE alone in CDM–B had little effect on the already poor cell growth. In the presence of the combination of YE and rHSA, however, CHO cell growth displayed rates comparable to that of CDM–A. The combination of supplements again delivered best overall performance with respect to CHO cell growth and productivity (see Figures 5c and 5d).


blog comments powered by Disqus

ADVERTISEMENT

ADVERTISEMENT

AbbVie/Shire Deal Officially Off
October 20, 2014
Amgen Sues Sanofi and Regeneron over Patent for mAb Targeting PCSK9
October 20, 2014
EMA Works to Speed Up Ebola Treatment
October 20, 2014
Lilly to Close Manufacturing Facility in Puerto Rico
October 17, 2014
BioReliance Introduces New Predictive Assays
October 17, 2014
Author Guidelines
Source: BioPharm International,
Click here