4 January 2023 Elizabeth Tan

What are some of the challenges in cryopreservation?

Biopreservation is a process by which the degradation of biologics is suppressed to enable the recovery of structure, viability and function. The most common method for long-term biopreservation is cryopreservation, with temperatures lower than  0˚C, generally ranging between -80 and -196˚C. Cryopreservation leverages the effect of decreased temperature to suppress molecular motion and arrest metabolic and biochemical reactions. It is the process of preserving the biological structure and/or functions of various living systems by freezing and storing at very low temperatures.

The applications of cryopreservation can range from agriculture, aquaculture, ecology, cell and gene therapy, biology research, and supporting tissue and organ preservation, to name a few.

There are, however, many uncontrolled variables in the process that pose challenges to a successful cryopreservation process. To take advantage of the protective effect of low temperatures, damage during freezing and thawing must be minimized. Currently, the use of cryoprotective agents (CPAs) such as glycerol, dimethyl sulfoxide (DMSO) or hydroxyethyl starch (HES) are employed to protect the inside and outside of the cells from the physical and chemical stresses that occur during freezing and thawing.

However, they do not fully prevent the deadly effects of ice recrystallization.  Ice recrystallization is one of the most significant challenges in the cryopreservation process.


What is Ice Recrystallization?

Ice recrystallization can be defined as the process whereby ice crystals formed during the freezing process grow larger at the expense of smaller ice crystals. While the exact reason behind the phenomenon of ice recrystallization remains debatable, the significance and benefits of preventing this process have been recognized for many years. Ice recrystallization leads to lower post-thaw cell recovery and decreased cell function.

In medicine, cryostorage is an important process to preserve biological materials or precious cell types such as stem cells (or other progenitors) or red blood cells. However, as with any cold storage practice, ice recrystallization remains a major problem and is a significant cause of cellular damage and cell death. This results in a poorer cryopreservation process where there are lesser viable cells. Preserving cell yield, viability and function is essential to furthering research and saving lives.

The industry implications related to the imperfections of the current cryopreservation methods vary among the broad range of its applications. Ineffective cryopreservation can, for example, fail to help save endangered species, force vaccine manufacturers to use expensive and complex transportation and storage equipment, or prevent the proliferation of promising, potentially life-saving treatments. These, of course, translate into increased manufacturing, transportation and storage costs and hamper the advance of otherwise profitable industries.

Although nature has given several organisms the ability to mitigate cellular damage during exposure to cold temperatures, the tools they use, such as peptides and glycopeptides, are not effective cryoprotectants in various medical and commercial applications.

To address the issue of ice formation and growth, the team at PanTHERA CryoSolutions has developed Ice Recrystallization Inhibitors (IRIs), which are patented small molecules that control ice crystal size and growth throughout the cryopreservation process of cells and tissues. When added to traditional cryopreservation buffers, the molecules can help create a more hospitable cellular environment.


By controlling the variables in the cryopreservation process, PanTHERA’s IRIs improve post-thaw recovery and functionality of cells which can have a positive impact on various industries where cryopreservation is commonly used, including agriculture, the preservation of food, research and medical applications, amongst others.

About PanTHERA CryoSolutions

PanTHERA CryoSolutions is a Canadian corporation that designs and manufactures cryopreservation solutions for cells, tissues and organs for research and clinical markets. Our patented ice recrystallization inhibitor (IRI) technology exceeds other products by providing superior cryopreservation and increasing post-thaw cell recovery and function for our customers. The technology enables the use of significantly less costly storage and transportation systems limiting the need for liquid nitrogen use for some cell therapy applications.

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