Cryonics Is Still A Largely Overlooked Field. That Could Change In The Near Future.

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Cryonics is the practice of freezing human remains, in the hope of preserving them for a future day when they can be revived. This idea has been overlooked or even mocked for decades, pushed aside as wishful thinking without any evidence to back it up. The science around cryonics has progressed since its inception, and it is starting to look less and less like a pipe dream.

The field of cryonics currently looks a lot like that of rejuvenation research a few decades ago – a field with compelling evidence behind it, but lacking in recognition and funding. Today, the science of rejuvenation is taken much more seriously and has branched into many new lines of research, some of them receiving significant funding (though still not as much funding as we believe they deserve). In comparison, cryopreservation still has a small following and derives much of its limited funding from donating philanthropists.

How does cryonics achieve the same growth that rejuvenation has over the past few decades? Rejuvenation reached a tipping point in growth as evidence of significant lifespan extension in animals became more widely reported, as our understanding of the ageing process improved, and as new technologies such as senolytics were developed. Important advances are also being made in the field of cryonics, and these will help attract more media attention. A key milestone towards a similar tipping point for cryonics will be the development of reversible vitrification of human organs.

The North American wood frog can survive freezing temperatures for months by flooding its body with glucose (sugar). This allows up to 65% of the water in its body to freeze and thaw without causing significant tissue damage. Could we use a similar approach to preserve human tissues?
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Vitrification is works by placing cells, tissues or organs in an environment that prevents ice crystals from forming by using chemicals called cryoprotectants. Cryoprotectants can make water harden like glass, avoiding the crystals that are responsible for the cell damage that usually occurs during freezing. This means that in theory, cryopreservation can be reversed without having to worry about restoring cellular structure to its original state. The problem is that the cryoprotectants used for preserving whole organs are themselves quite toxic. Overcoming this would potentially have huge implications for organ transplantation alone (allowing donor organs to be preserved for far longer periods of time) and eventually for the safe preservation of human remains for later resuscitation.

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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While reversible vitrification could be many years away, excitement for cryonics is far from unjustified. Indeed, one could make the argument that being unable to safely reverse cryopreservation now is of little relevance, since the primary aim is to preserve people until medical technology has significantly advanced. In other words, we should start cryopreserving people now and worry about thawing them later.

If developments in cryonics continue on their current trajectory, we could expect to see rapid commercial growth by the mid to late 2030s, with widespread adoption of reversible organ vitrification. The leap from this to cryopreservation upon death will begin to seem a lot more realistic for many sceptics.