If you have spent any time in the cryonics space, you may have come across a bunch of terms that you don’t understand. What does cryoprotection, SST, and vitrification mean? It can all be a bit overwhelming. But don’t fret, in this article you’ll get a simple explanation of all the most important cryonics terms. Let’s start by making sure we’re on the same page about cryonics.

Cryonics is the practice of preserving a human or animal body at very low temperatures with the hope of reviving them in the future. The idea is that by cooling the body to extremely low temperatures, it can be preserved in a state that allows for future medical technology to bring the individual back to life. Cryonics is a last resort chance for life extension when current medical technology can no longer help. You may have seen terms like cryonics, cryopreservation, cryogenics, and biostasis used seemingly interchangeably. So what exactly is the difference between them?

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Biostasis, Cryopreservation, and Cryogenics

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Let’s start with Biostasis, since it’s the most broad concept we’ll be going over. Biostasis is a term used to describe the slowing or halting of biological processes in order to preserve an organism in a state of suspended animation. Biostasis is found in nature in various forms, such as in certain species of frogs and fish that can survive in frozen water by slowing down their metabolism to a point where they can survive in harsh conditions. Some microorganisms, including certain bacteria, are able to enter a dormant state in order to survive in conditions where resources are scarce. Additionally, some plants have mechanisms to survive in extreme conditions, such as desiccation, where they can survive for extended periods without water by slowing down their metabolism. Biostasis is an effective survival strategy that allows organisms to survive in harsh or unfavorable conditions until more favorable conditions return.

Biostasis is a term that is relevant in the field of cryonics because it describes the state that cryonics patients should be placed in, which is a state of suspended animation. This term is agnostic to the method used to achieve this state, whether it is through freezing, hypothermia, or the use of chemical preservatives. This allows for a broad range of techniques to be considered and evaluated for their effectiveness in achieving the desired state of biostasis. The methods used today to preserve cryonics patients may no longer be the best method in the future when medical technology is more advanced. That's why it's important for cryonics members and organizations to keep the term biostasis in mind, as it can help them to avoid getting too attached to just one method of preserving patients and ignoring other potential methods that could better achieve the goals of cryonics.

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The current method used to preserve cryonics patients is called cryopreservation. Cryopreservation uses extremely low temperatures to preserve the tissues and cells in a state where they can be restored to their previous function in the future. Cryopreservation can be done by using liquid nitrogen, which cools the specimen down to around -196°C. This technique can be applied to a wide range of biological materials, including whole organisms, cells, tissues, and even semen, eggs, and embryos.

So let’s summarize what we’ve learned so far. Cryonics is the practice of preserving someone with the goal of future restoration of life. Biostasis is the state which cryonics patients must enter in order to be preserved for the future. And cryopreservation is currently the best method of achieving biostasis in humans. 

Now you might be thinking we forgot about cryogenics, but there’s a good reason we haven’t integrated it into the previous paragraphs. Chances are, if you’ve seen the term cryogenics used in the context of cryonics, it was probably used incorrectly. Cryogenics is the branch of physics that studies the production and effects of extremely low temperatures. Often when people use the term cryogenics, what they should really be using is cryonics. For the sake of accuracy, it’s important to note that cryogenics and cryonics are very much not the same term.

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The Cryopreservation Procedure

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Now that we’ve gotten the big concepts out of the way, let’s look at some more precise cryonics terms. If you’ve looked into getting a cryonics plan you may have come across the acronym SST. SST stands for standby, stabilization, and transport, which roughly describes the responsibilities of the medical team that travels to the patient to begin the cryopreservation procedure. Most cases of death have forewarning, in which case a medical team will travel to the location of a cryonics patient and wait for the patient to be pronounced dead so that the procedure can begin as quickly as possible. This period of waiting at the patient’s location is called standby. 

Stabilization in human cryopreservation refers to the process of preparing the body or brain for preservation by minimizing damage caused by a lack of oxygen to the cells. This can involve steps such as administering medications to prevent brain damage, cooling the body to slow metabolic processes, and performing cardiopulmonary support to keep any remaining oxygen circulating throughout the body. The exact steps carried out during patient stabilization will depend on the condition of the patient and which cryonics provider is carrying out the procedure. 

Once stabilization is complete, the SST team will transport the patient to the long-term storage facility. Depending on how far away the patient is from the facility, they will either be transported in a cryonics ambulance or packed with dry ice and transported by airplane.

It’s common for people to think of cryonics as “freezing” people, but the reality of the cryopreservation procedure is more sophisticated than just freezing. Freezing is avoided during cryopreservation as much as possible, because the formation of ice crystals would cause serious damage to cells. Maybe you’ve had experience sticking a vegetable in the freezer, and noticed how mushy it became after being defrosted. The goal of cryonics is to give patients the best chance at future revival, not turn them into mush. This is why patients will undergo cryoprotection. Cryoprotection is the process of preparing a patient to be exposed to extremely low temperatures while incurring as little ice formation as possible. 

One of the key components of cryoprotection is the use of cryoprotective agents (CPAs). CPAs are essentially medical grade anti-freeze which are perfused into a patient in place of their blood. These CPAs are also hyperosmolaric which means that they pull water out from the surrounding tissue. Under ideal conditions, this allows for patients to be cryopreserved with little to no freezing.

The purpose of CPAs is to prepare the patient for vitrification. Vitrification is a process that is used in cryopreservation to prevent the formation of ice crystals in cells and tissues. Unlike freezing, vitrification converts the water in the cells and tissues into a glass-like state, which does not form crystals and can be preserved at extremely low temperatures without damaging the cells. Once a patient is cooled to around -130°C they pass the so-called glass transition temperature and become vitrified.

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Conclusion

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You may have noticed us using the term member and patient a few times during this article. So what’s the difference? Member refers to a person that is signed up for cryopreservation, but is still alive. The member becomes a patient after their legal death, and remains a cryopreserved patient until their potential revival in the future. Now that those terms have been explained, you’re officially well informed on the most important terms in cryonics! With this understanding you should have no problem learning more about this topic and deciding whether cryonics is the right choice for you. 

If you want to know more about cryonics, you can find lots of relevant information on our website and by engaging with the global cryonic community on Discord. If you have any questions about cryonics or Tomorrow Bio, schedule a free consultation call with one of our experts. And if you’re ready to sign up and secure your cryopreservation, we’d be happy to welcome you as a member.