METHONOVA™ applications

METHONOVA™ applications

Methylcellulose Assays

In the 1960’s, several researchers determined that only cells capable of proliferation were able to form colonies. Therefore, counting the colony forming units could be a good surrogate to counting cells. Semi-solid methylcellulose has become a polymer of choice for colony forming cell assays (CFC).

The final concentration of methylcellulose used in the assays is typically 1-1.5%, allowing cells to grow while discouraging cell migration and encouraging colony formation. Nutrients, proteins and growth factors, or serum-free alternatives, are added as well.

METHONOVA™ is tested for cell compatibility via a cytotoxicity test with mammalian cells, and is suitable for use in cell assays.

Cell culture media

The biopharmaceutical market continues to grow at a rapid pace, fueling the need for cells to produce proteins, cell, or gene therapies. Cell production yields greatly impact the production time and cost of biopharmaceutical therapies and are still -in general- considered a bottleneck to further scale up and scale-out approaches. Cell culture media have been significantly optimized over the last years to improve production yields. While traditional media often included media from animal and human origins, the industry is evolving towards current expectations for chemically, defined and serum/xeno-free media.

Suspension cells

Some cells can be grown in suspension, as is the case for commonly used Chinese Hamster Ovary (CHO) cells, which are used for the production of monoclonal antibody (mAb) drugs. Much effort has been placed on improving protein yield by reducing stress factors on the protein during the process, and on upstream process intensification. One such approach is the use of additives in the upstream process to boost cell production. For example, Poloxamer 188 is an additive that is believed to function as a shear protectant, and is now incorporated into many commercial media products. As illustrated on Figure 1, methylcellulose could also serve as a media additive to increase the viable cell density in CHO cultures.
Figure 1- Viable DG-44 CHO cell density in shake flask suspension with methylcellulose vs. Poloxamer 188

Adherent cells

Adherent cells, such as mesenchymal and induced pluripotent (MSC & iPSC) stem cells, typically bind to surfaces to aid expansion. This surface can be a T flask, a microcarrier, or other suitable (3D) environments. After cell proliferation, the cells are usually removed from the surfaces by using trypsin to cleave the cell’s binding proteins. Cells might be damaged during this process, potentially impacting cell yields and introducing uneven therapeutic potency.
The ability to form cell aggregates (or spheroids) is gaining interest as an alternative 3D model for cell growth, particularly for stem cell producer cells. Similar to its application in cell assays, methylcellulose can help colony formation via protection of the cells from adhering to surfaces.

Cryopreservation

Cryopreservation is a necessary step for preservation of nearly all cells and cellular therapies. It is particularly important for immunogenic therapies (e.g., CAR-T) as cells require cryopreservation after expansion for transport and patient prep.
Successful cryopreservation depends on cryoprotectants as well as the process (time to freeze, temperature, time to thaw, etc.). As the industry seeks alternatives to animal-derived serum and traditional cryoprotection agents like DMSO, methylcellulose has been evaluated as an alternative.

3D bioprinting

One of the newer frontiers in biopharma is to move from 2-Dimensional (2D) to 3-Dimensional (3D) cell growth, mimicking an in-vivo like environment to promote nutrient distribution and eventually cell proliferation. With the push to eliminate the use of animal derived products such as extracellular matrices, non-animal derived hydrogels are increasingly investigated for the formation of scaffolds for directed cell growth. Hydrogels containing methylcellulose, in addition to other biopolymers such as hyaluronic acid or alginates, can be used for molding applications such as 3D bioprinting. The thermo-responsive behavior of methylcellulose allows for gel formation and cell growth and then removal of the methylcellulose by reducing the temperature. Methylcellulose can be particularly useful to produce softer gels vs. stiffer structures.