Cryonics and Cryopreservation FAQs

Below are the most common and important questions that we have faced when discussing cryopreservation and cryonics. Please let us know if you think any important aspect is missing.

What is cryonics?

Cryonics is the cryopreservation of whole humans, thus far only applied to deceased individuals. Human cryopreservation is also sometimes called medical biostasis, cryogenics or suspended animation.

What is cryopreservation?

Cryopreservation is the process of placing cells, organs or even whole organisms at low temperatures so that they remain in a state of suspended animation and function is preserved.

What is cryobiology?

Cryobiology is the study of biological materials at low temperatures.

What is vitrification?

Vitrification means turn to glass; it is a process that replaces water molecules with a viscous compound that does not freeze, instead it forms a dense gel at the so-called "glass transition" temperature, around -80 C / -130 C, while retarding the formation of ice. Vitrification is the preferred technology in cryonics.

What is the UK Cryonics and Cryopreservation Research Network?

We are a group of UK researchers who, together with international advisors, aim to advance research in cryopreservation and its potential applications, including ultimately the idea of cryopreserving whole humans.

How does the UK Cryonics and Cryopreservation Research Network differ from Cryonics UK?

Cryonics UK provides assistance to those within the UK who wish for their body to be cryopreserved. We at the UK Cryonics and Cryopreservation Research Network provide no assistance on cryonics. Instead, we are researchers who aim to promote academic and industrial activity on cryopreservation in general.

Why should I care about cryopreservation?

Given the importance of organ transplants and the growing field of tissue engineering, perfecting cryopreservation methods would have a profound impact on medicine. For example, as progress continues in tissue engineering, vitrification could hold the key not only to long-term organ banking, but in storage of personalised lab-grown tissue replacements. Besides, low-cost, long-term organ banking through safe, super-low temperature vitrification of whole organs that could be rewarmed when needed for transplant would equate to countless thousands of lives saved each year.

Can you recommend protocols or approaches for my cryopreservation needs? Can you advise on my project?

Possibly, please contact us for details. Our goal is to foster collaborations with other academics and with industry.

Are there animals that naturally survive freezing?

Yes, there are species of insects that appear to survive complete freezing during winter. Likewise, some species of frogs can produce their own antifreeze during winter and be partly frozen.

Don't ice crystals destroy cells during cryopreservation?

Ice crystals can indeed damage and destroy cells. Cryobiologists employ antifreeze compounds (cryoprotectants) to minimize ice formation. In addition, protocols like vitrification emphasize ice-free cryopreservation via the use of high concentrations of cryoprotectants.

What are the major challenges in cryopreservation?

Ice information is still an issue in some cases and can cause damage. Another major challenge is that cryoprotectant agents have toxic effects on human tissues with prolonged exposure, through mechanisms still poorly understood. Vitrifying large organs can also result in fractures due to different cooling rates in different parts.

Can human organs be cryopreserved?

At present, cryopreservation technology is only successful for cell lines and small tissues like corneas. More research is required before whole organs can successfully be cryopreserved while retaining their biological integrity.

Have there been recent advances in cryopreservation?

Yes, there has been progress in cryopreservation. A team led by Hal Sternberg of Biotime claimed to bring back to life baboons that were previously cooled to one degree Celsius. They injected a substance called Hextend to replace the blood and protect the cells from deterioration. Incredibly, this may soon become routine for emergency care patients. Hasan Alam at Massachusetts General Hospital is working on a similar approach of replacing blood by a cold saline solution to drop the temperature of emergency patients and protect the bodies from damage while undergoing surgery. At a more basic science level, Gregory Fahy and colleagues vitrified a rabbit kidney and then transplanted it into a live animal with the kidney maintaining some degree of function. The same team showed that rat and rabbit brain slices can be vitrified and rewarmed and still maintain neural responses. And work led by John Bischof showed that cryopreserved tissues can be safely rewarmed using nanoparticles suspended in a cryoprotectant solution that are then heated using a magnetic field.

What does cryonics involve?

After being pronounced dead, temperature is gradually lowered and patients are perfused with antifreeze compounds (cryoprotectants) to prevent ice formation, temperature is then lowered further and eventually patients are cryopreserved in liquid nitrogen at very low temperatures (< -130 C), hoping one day they will be devitrified, rewarmed and revived.

What about just cryopreserving one's brain?

Indeed, some cryonics service providers also offer a "neuropreservation" option in which only the head is cryopreserved. This is cheaper than whole body cryopreservation and is based on the assumption that replacing human organs will be so commonplace in the future that creating a new body will be feasible.

What sorts of damage occur during cryonics?

With today's technology, cryonics severely damages the body's cells. Even under optimal conditions (i.e., the procedure starts right after death), there are several problems in cryonics. In particular, cryoprotectant agents have toxic effects on human tissues with prolonged exposure. Vitrifying large organs like the brain can also result in fractures due to different cooling rates in different parts. Under non-optimal conditions (i.e., if a significant time elapses between death and being cryopreserved) much more damage can occur because cells start to die, and brain cells in particular start to die within minutes after cardiac arrest, due to lack of nutrients and oxygen (called ischemia).

How can damage during cryonics be repaired one day?

No doubt it will take huge scientific advances in areas like tissue engineering and regenerative medicine to make cryopreserved individuals alive and healthy again. In addition, repair at the molecular level using nanotechnology will be necessary, yet this remains in the realm science fiction. That said, it is impossible to predict how technology will progress in the coming decades or centuries.

How much does cryonics cost?

Costs of cryonics vary widely across service providers, but are generally in the range of $20,000 - $200,000 (or about £15,000 - £150,000).

How do people pay for cryonics?

Most people pay using life insurance.

Are you affiliated and/or can you recommend any cryonics service provider?

No, we are not affiliated with any cryonics organization. Some of our advisors also advise cryonics organizations, while others in our network have been critical of cryonics. But as a research network we have no links to cryonics service providers. We are also not in a position to endorse or recommend any cryonics service provider.

Can you assist me in making arrangements for cryonics?

Unfortunately no. We are solely a research organization. Please see our list of links for the major cryonics service providers who can help you.

Aren't scientists opposed to cryonics?

Many scientists doubt whether current cryopreserved individuals can ever be brought to life given the amount of damage endured. On the other hand, in 2004, an open letter on cryonics advocating that it is a legitimate scientific enterprise was signed by 63 scientists, including eminent researchers from Oxford, Cambridge, Caltech, NASA, Columbia University, UCLA, MIT, etc. Therefore, there are voices on both sides of the debate. For some recent arguments pro and against cryonics please see The False Science of Cryonics and The Science Surrounding Cryonics.

What are the chances of revival from cryonics?

Opinions diverge widely from zero to over 50%. Most scientists agree that the chances are low but not impossible.

When will cryonics patients be revived?

As mentioned above, it will take huge scientific advances to revive cryopreserved individuals, including developing new technologies like nanotechnology. Therefore, while it is impossible to predict the pace of future technological breakthroughs, most scientists would agree that it will take at least decades, but possibly even centuries or millennia, until we have the technology to revive cryonics patients.

Will cryonics patients retain their memories?

The goal for cryonics is for revival with identity preserved, i.e., most memories, cognitive abilities and personality intact, not revival as a different person. Whether current cryopreservation protocols result in too much damage to the brain for the information that defines the self to be lost is unknown. Rat and rabbit brain slices can be vitrified and rewarmed and still maintain neural responses, yet the human brain is significantly larger and more complex.

Is cryonics a scam?

Because cryonics is unproven, some have called it a scam. However, most cryonics service providers are nonprofit organizations who recognize the unproven nature of cryonics.

Is cryonics selfish?

A desire to live is reasonable and intrinsic to the human condition. Therefore, cryonics is not more selfish than a terminal patient wishing to receive an expensive treatment to live a few more months. Likewise, it is possible that cryonics patients will impose healthcare costs on future generations, which can be considered selfish, yet many current lifestyles that people choose (e.g., smoking or obesity) also impose massive healthcare costs on society.

Won't cryonics contribute to overpopulation in the future?

Only a few hundred individuals are cryopreserved at present, so in a world with billions of people the impact of cryonics in the future human population will be negligible. That said, if human cryopreservation were to be feasible (see below), it is possible for millions of patients to be cryopreserved which could lead to future social and medical challenges. Nonetheless, fears of overpopulation are not a valid reason to reject any medical breakthrough that preserves human life.

What would be the implications of successful human cryopreservation?

Reversible and safe human cryopreservation would be a revolutionary technology in the field of critical-care. Patients with terminal diseases, including children, could opt to be placed on cryostasis until a cure were discovered. In a sense, we would have an alternative to death, which has profound philosophical, ethical and medical implications. Suspended animation from reversible cryopreservation may also be necessary for space exploration.