"Freezing" application in 3 biopharmaceuticals systems: Cryoprotection of cells
In the field of biopharmaceuticals, the key elements for the success of cryopreservation include effective freezing, thawing, ice crystal formation, and the use of correct cryoprotection. Among them, cells, proteins, and viral vectors are the most popular cryopreservation projects. The following will introduce the basic applications of these three research projects in the field of biopharmaceuticals and their precautions in the cryopreservation process:
Cryoprotection of cells
Cell cryoprotection is usually used in biological research. At first, it was used in normal cell culture research. To obtain the accuracy of the research results, it is necessary to use the same cell line as a research sample, but cell culture takes much time, sometimes, the researcher doesn't have enough time to complete the full research. Therefore, the cultured cells must be "frozen" to temporarily enter a dormant state and be properly stored, to defend the cell line from dying. With the popularity of cell therapy, how to preserve cells through cryopreservation has become more important to academic and medical circles. The following are the relevant precautions for your integrated cell cryoprotection:
Further Reading: The application of Cell Therapy
- In order to prevent potential damage caused by ice crystallization during the thawing process, it is necessary to defrost at a relatively fast heating rate.
- In order to minimize the cell damage caused by the "solute effect", it must be added the cryoprotectants. Such compounds will not ionize in aqueous solutions and have relatively low toxicity to cells at low temperatures.
- If it is used for cell therapy, it should be considered whether it will require a washing step due to the addition of cryoprotectants before the final use on the patient, which may pose a risk to the viability and performance of the cells after thawing.
- Any potential cytotoxic effects of cryoprotectants (especially DMSO) should avoid sudden temperature changes to lower the temperature.
- The relatively slow cooling rate may cause it to freeze in the body phase, that is, the suspension medium. The solute is excluded from the crystals of this extracellular ice, resulting in an increase in the osmotic pressure of the remaining, unfrozen suspension medium. Imposes potentially lethal osmotic pressure, commonly referred to as the "solution effect"
- As cell clusters, spheres, organoids, and tissues become more important, slower cooling rates may be necessary for therapeutic importance.
- The most commonly used concentration of DMSO is 10% v/v, the same as stem cells. The obvious trend of reducing it to 5% v/v is obvious. With or without the addition of non-permeable CPA, the recovery rate of cells after thawing can be improved, and the amount of DMSO injected into the patient can be reduced.