Longevity Briefs: Could This New Organ-Freezing Technology Save Lives?

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Longevity briefs provides a short summary of novel research in biology, medicine, or biotechnology that caught the attention of our researchers in Oxford, due to its potential to improve our health, wellbeing, and longevity.

Why is this research important: If you ever find yourself in need of an organ transplant, you could be waiting a very long time. Most human organs can only be preserved at low temperatures for a few days, which means that the availability of donor organs is severely limited by the constraints of time and distance.

To preserve organs for longer periods, they would need to be cooled below freezing point, which results in the formation of ice crystals that destroy the organ at the cellular level. This damage can be avoided using a process called vitrification: the organ is perfused with chemicals called cryoprotectants, which make the water within the tissue solidify ‘like glass’ at low temperatures, preventing the formation of ice crystals. Unfortunately, these chemicals are quite toxic, and scientists haven’t yet figured out how to safely thaw a human organ that has been vitrified.

Water freezes to form a crystalline solid. Ice crystals grow in size over time, causing havoc at the cellular level (left). In vitrification, water molecules are immobilised by cold temperatures, but are prevented form forming crystals by the addition of cryoprotectants (right).
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What did the researchers do: Scientists are exploring an alternative method for preserving tissues at low temperatures called isochoric cryopreservation. Traditionally, vitrification is carried out at normal atmospheric pressure, whereas isochoric cryopreservation occurs at constant volume. The sample to be frozen is placed in a confined chamber of constant volume, which raises the pressure of the sample as the freezing process begins. This changes the properties of the water within the sample in such a way as to reduce ice crystal formation, meaning that far less cryoprotective agent is needed to vitrify the tissue. This should make mitigating the toxicity of these chemicals easier.

Key takeaway(s) from this research: We’ve previously discussed the science of vitrification with the goal of preserving human organs and, perhaps one day, allowing clinically dead humans to be preserved for later revival. Isochoric cryopreservation is just one example of how we might be able to get around the current irreversibility of this technique.