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Why Cryopreservation is No Longer Science Fiction | with Until Co-founder and CEO Laura Deming

What if we could pause biological time to wait for a cure for a disease? Thanks to innovations and research in reversible cryopreservation, this possibility is no longer just science fiction. Sarah Guo sits down with Laura Deming, CEO and co-founder of biotech startup Until, to dive deep into the growing field of reversible cryopreservation. Laura talks about how her time as a Thiel Fellow as well as her founding of the Longevity Fund fueled her obsession with solving the “social blindspot” of aging. Laura details how her new startup, Until, seeks to build tools that allow for “pressing pause” on biological time, starting with human organs with the hopes of scaling up to full body medical hibernation. Together, they also discuss why ice is the enemy of tissue, using engineering tools to help solve biological problems, and how this technology may revolutionize organ transplantation by removing time as a variable. Sign up for new podcasts every week. Email feedback to show@no-priors.com Follow us on Twitter: @NoPriorsPod | @Saranormous | @EladGil | @LauraDeming | @untillabs Chapters: 00:00 – Cold Open 01:08 – Laura Deming Introduction 01:53 – Why Laura Focused on Cryo Preservation and Longevity 06:20 – Bringing on Co-Founder Hunter Davis 07:55 – Until’s Goal 10:10 – Other Use Cases for Cryo Technology 12:22 – Scientific Challenges in Cryo Tech 15:36 – Using Engineering Principles to Solve Biological Problems 20:18 – Scaling Up Cryo Preservation 21:48 – Leading and Recruiting at Until 25:02 – Why Hasn’t Cryo Tech Been Worked On More? 27:14 – Making Time Not a Variable in Organ Transplants 29:06 – Changing How the Molecular World is Depicted 30:47 – Conclusion

Laura DemingguestSarah Guohost
Jan 28, 202630mWatch on YouTube ↗

At a glance

WHAT IT’S REALLY ABOUT

Reversible cryopreservation roadmap: from transplant organs to human hibernation

  1. Until is developing reversible cryopreservation—cooling living systems enough to halt damage and “restart” them—by first targeting single-organ preservation for transplants.
  2. Deming argues the core scientific problem is not whether cryopreservation can work (it already does for embryos and some tissues), but whether it can scale to large, vascularized organs and eventually whole bodies.
  3. Key technical challenges center on avoiding ice formation (which physically damages tissue), controlling cooling/rewarming rates, and balancing cryoprotectant toxicity against engineering improvements.
  4. The long-term vision is a new form of critical care: “an ambulance to the future” that could pause a dying patient’s biological clock until a therapy or trial becomes available, with the brain remaining the biggest unknown for whole-body reversibility.

IDEAS WORTH REMEMBERING

5 ideas

Cryopreservation is already proven—scaling is the frontier.

Embryos have been cryopreserved for decades and later developed successfully, and prior academic work suggests kidneys can be cryopreserved and regain function. Until frames the key question as scaling to larger, complex, vascularized systems with consistent outcomes.

Avoiding ice is the central technical constraint.

Ice formation expands water and can rupture membranes and tissue structure. The strategy emphasized is minimizing time in the “danger zone” where ice nucleates and pushing into temperatures where ice formation effectively stops.

Ice formation is probabilistic, which creates an engineering opening.

Because nucleation is stochastic, controlling time-at-temperature and thermal gradients can reduce the probability of ice formation. This turns part of the problem into rate control (cooling/rewarming) and system design rather than only biological discovery.

Engineering progress can reduce biological risk (especially toxicity).

Faster, more uniform cooling and rewarming can allow lower concentrations of cryoprotective agents, which are often toxic at effective doses. Until’s approach highlights trading engineering difficulty for reduced chemical/biological burden.

The near-term “product” is transplant logistics, not sci-fi hibernation.

Organs currently expire quickly, forcing last-minute flights, rushed matching, and “house arrest” for patients near transplant centers. Reversible organ cryopreservation would make time less binding, improving matching and scheduling and reducing organ wastage.

WORDS WORTH SAVING

5 quotes

Our long-term goal is reversible whole body cryopreservation for medical hibernation. But in the near term, what we work on is reversibly cryopreserving single human organs…

— Laura Deming

Single years can make the difference between a patient dying of terminal illness and living long enough to make the critical cure… What if you had an ambulance to the future?

— Laura Deming

Making time not a variable changes the whole paradigm.

— Laura Deming (quoting a transplant surgeon)

The main question is not, ‘Is this possible to do at all?’ It’s, ‘Is it possible to scale up?’

— Laura Deming

If you could instantaneously cool and rewarm, then you wouldn’t have to put any CPA in… but that’s not something… feasible for a large system.

— Laura Deming

Medical hibernation as critical careOrgan transplantation timing constraintsIce nucleation and vitrification regimesCryoprotectant agents and toxicity trade-offsEngineering vs. biology leverage via temperature controlScaling from embryos/tissue to organs to animalsField stigma, funding gaps, and “antimimetic” science

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