Transient Warming Events and the Effects on Cell Viability

ThermoGenesis BioArchive Automated Storage Systems

When it comes to cell processing and cell manufacturing, it’s extremely important that samples are collected and stored properly so that they retain the greatest viability for use in the future. As you can imagine, there are some logistical challenges associated with cryopreserving samples at just the right temperature for an extended period of time, including the challenges of environmental factors affecting the samples in what’s known as transient warming events (TWE). These are brief moments when frozen blood samples are exposed to air and other environmental factors. These transient warming events and their effect on cell viability have been carefully documented, underlying the usefulness of avoiding TWEs.


The Importance of Cell Storage in Cell Therapy Manufacturing

Cryopreservation is the process of using ultra-low temperatures to preserve living cells for long periods of time. It is an essential aspect of the cell manufacturing process for many cell therapies, such as CAR-T and Mesenchymal Stem Cell based therapies. In order to maintain the greatest possible viability, cells must be consistently stored at these ultra low temperatures. 

The cell manufacturing process involves logistical aspects that pose a unique challenge to maintaining the samples at the necessary temperature.  For example, a sample that is frozen in a controlled rate freezer at -196⁰C and then transferred to the final conventional freezer for storage at -196⁰C will experience ambient air temperature (+22⁰C) during the move.  Even the simple act of opening and closing the freezer or the removal of the rack from the freezer to pull a sample exposes all of the other samples in the freezer to room temperature. The transportation process is another instance when the samples could be exposed to transient warming events. When a sample is needed for transplantation it will be removed from the freezer and transported to the transplant center.  Great care must be taken to quickly and carefully remove the sample from the freezer and place it into the liquid nitrogen dry shipper while maintaining the sample temperature. 


How Transient Warming Events Affect Cell Viability

Technical advances in the processing and freezing of patient samples have allowed cells to be frozen in time, thus enabling therapies not previously available.  If stored and maintained properly, cells should be as good after 10 years of storage as they were on the day they were collected. The degree to which they maintain their quality is referenced in their viability. 

When cell samples experience transient warming events, they will experience a reduction in their post-thaw viability. For example, if a cell sample were exposed to a warmer temperature, even for a very few minutes, it could experience a viability decrease of approximately 9%

When storing a manufactured product intended for cell therapy it is critical to ensure that the samples are cryopreserved and maintained at the appropriate temperature without fluctuation.


ThermoGenesis Offers Cryopreservation Solutions with the BioArchive System

One way to alleviate the risk of exposing cell samples to transient warming events is through automated cell banking. These are systems that are designed to control the freezing and individually store each sample in order to prevent them from experiencing a transient warming event.  Once cells are stored they are protected from the room environment, and their use increases the safety and efficacy of the cell manufacturing process. 

An automated system like the BioArchive® uses proven computer-controlled technology, and tracking software, which offers the best protection for cell samples collected today and ensures their viability when it’s time for their use.


How The BioArchive Helps Minimize Exposure to Transient Warming Events

The BioArchive® System offers cell storage, tracking, and retrieval with automation and certainty. The system offers constant temperature control through closed-system sample handling with robotic storage and retrieval, resulting in minimal exposure to transient warming events. This highly innovative product automates the cryopreservation process and boasts a 94 percent post-thaw cell viability rate. The Sample Management Software (SMS) provides accurate, individualized, fully documented freeze and sample tracking, history and inventory, ensuring GMP-compliance. 

ThermoGenesis Holdings, Inc. is a pioneer and market leader in the development and commercialization of automated cell processing technologies for the cell and gene therapy fields. We market a full suite of solutions for automated clinical biobanking, point-of-care applications and large-scale cell processing and manufacturing with a special emphasis on the emerging CAR-T immunotherapy market. We are committed to making the world a healthier place by creating innovative solutions for those in need.

For more information on our entire suite of automated solutions, please contact our sales team.

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