How Until is Engineering Away Time in Organ Transplants | Laura Deming
In a Nutshell
Until co-founder and CEO Laura Deming outlines the company's mission to achieve reversible whole-body cryopreservation for medical hibernation, starting with near-term reversible cryopreservation of human organs to eliminate transplant timing constraints—organs currently expire quickly, forcing rushed logistics like private jets and patient "house arrest" near centers. Key challenges include preventing damaging ice formation by vitrifying tissues below -30°C using cryoprotectants, with proven successes in embryos (30+ years viable) and rabbit kidneys (functional post-rewarm and transplant). This "freezes time" for critical care, enabling patients to await cures for fast-evolving diseases like metastatic melanoma, transforming inefficient matching and scheduling paradigms.
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What if you could take someone on their deathbed and hibernate them until a critical cure for their disease comes online? The ability to freeze time for humans. Until's long-term goal is reversible whole body cryopreservation for medical hibernation. In the near term, they focus on reversibly cryopreserving single human organs to help transplant patients get organs more efficiently. Making time not a variable changes the whole paradigm. The problem in cryopreservation speaks for itself.
Water expands when it forms ice, which is hard for tissue to take without substantial damage. There's a temperature below which ice formation stops happening. If you can get below that without ice formation, you're good. Human tissue, including embryos, is already reversibly cryopreserved for very long periods—kids have been cryopreserved as tiny embryos for 30 years. The main question is scaling up.
Welcome to No Priors with Laura Deming, previously founder of the Longevity Fund, now co-founder and CEO of Until. Discussion on progressing reversible cryopreservation: beginning with human organs, to small animals, hopefully to whole body. Sounds like science fiction, but covers scientific challenges, current status, and implications.
Laura's wished-for technologies included telepathy, upload, and freezing time for humans. She didn't think freezing time was workable, but it is.
Laura comes from longevity background, but reversible cryopreservation applies beyond that. She's obsessed with areas that should be worked on but aren't. As a kid, longevity seemed obvious. Surprising that it's not explicitly pursued as a goal. Longevity and aging occupy a weird realm—not fully socially recognized as diseases, so not seen as valid to work on. Technically, lifespan can be extended in many organisms; unknown in humans.
Longevity has a social blind spot.
Grew up in New Zealand, homeschooled, no normal biology class. As a kid, thought about how long people in her life would live. Hypothesized everyone should live until 10 years old and die immediately. Working backwards, thought dad was maybe 8, mom 7. Realized we don't all live to a certain age then die—there's uncertainty about lifespan determinants.
After lab work, MIT, Thiel Fellowship: why Longevity Fund? Took field literally—biggest problem is funding. Solved it by raising money via venture capital fund to push longevity drugs forward.
After years at fund, cryopreservation is one of the coolest problems—from counterfactual impact, technical delight, logical parts, social impact. Zero to one moment seeing the problem clearly. Next big thing after fund work.
Co-founder Hunter: if asked a question, returns next day with principled answer. Re-derived fundamental laws of stat mech for cryopreservation doc. Builds from simple models to complex pictures. Most fun person to work with.
Not a hard sell—problem speaks for itself. Hunter initially skeptical, but after thinking (ice formation, back-of-envelope math), saw feasibility.
Create new form of critical care. Example: metastatic melanoma went from 6-9 month prognosis to decade-plus survival or 50% surviving over a decade with new combination immunotherapies—in a single year.
Single years can make the difference between dying or living to critical cure. No way to press pause on biological time now. Ambulance of the future: hibernate deathbed patient until cure. Not decades initially—e.g., window for critical trial.
Hunter's father-in-law missed therapy by a couple months.
Long-term: reversible whole body cryopreservation for medical hibernation. Near-term: single human organs for transplants.
Other use cases like going to Mars or longevity: socially, people define themselves by social context. Most wouldn't hibernate recreationally (e.g., skip to future) because "I can't take everybody with me." High cost to current social reality. Makes sense only for serious cases where you'd die otherwise.
Hard to know what we want—people might decide differently from ultimate happiness.
Ice formation is stochastic: random nucleation then extension. Modulate rates to prevent ice. Avoid ice entirely (focus regime). Ice bad because water expands, damages tissue.
Temperature below which ice stops: traverse to ~ -30°C without ice, then stable long-term. Human embryos cryopreserved 30+ years, rewarmed viably for pregnancy.
We already cryopreserve human tissue (200-cell embryos, whole body at that scale) routinely long-term. Question: scale to large complex systems with vasculature, perfusion, diffusion, heat transfer.
Pulsing all molecular motion then restarting—even a cell survives.
In lab: engineering problems like warming quickly/safely.
Trade-off engineering difficulty and biological difficulty. Better engineering eases biology (not 100%, still bio questions). Rare in biology.
Temperature: beautiful tool linking molecular motion to measurable parameter, tunes relative passage of time at nanoscale. Allows physics theoretical toolkit—equations useful for modeling. Not true for most biology problems.
Possibility of more time for changing terminal illness course.
Example: even rewarming hard? Change surface area/volume ratio, distribute heat differently—engineering without changing biology.
Reducing/increasing temperature perfectly through organ makes it work.
Restate: engineering modulates cooling/rewarming rates, decreases needed cryoprotective agent (CPA) concentration (toxic). Instantaneous cool/rewarm needs no CPA. Still bio response to agents.
Work on two in parallel: scaling cryopreservation/rewarming to human organ scale, and whole rat.
We work on scaling cryopreservation and rewarming technologies to human organ scale. In parallel, we develop whole rat reversible hibernation and transitioning technologies from kidney learnings to rat context, plus rat-specific approaches.
When starting the company, full body cryopreservation felt far out if possible. Now, there's a clearer roadmap, with first steps faster than imagined. The big unknown for whole body reversible cryopreservation is the brain—unclear what injury it can sustain in a whole body cryopreservation protocol and the level of fidelity possible. That's a major neuroscience challenge.
For recruiting and leading with an unclear timeline on a big scientific goal:
- Have a clear timeline for the first product: reversibly cryopreserve organs to solve transplant timing issues.
- Transplant patients often miss organs en route due to expiration.
- Organs are precious but expire quickly after donor availability.
- Surgeons charter private jets to retrieve organs last-minute; patients stay within 2-hour radius of transplant center with pagers at all times.
The first product pauses time for organs, allowing as long as needed to transport to patients. This is near-term, aiming for studies and clinic quickly.
If we're serious about whole body reversible cryopreservation, we can't make a dent on organ timing problems—there's no version of not going through it.
It's a benchmark: if not doable, we're not the company for the long-term goal.
Focus on step one while everyone understands the broader mission. Communicate accurately: not claiming 100% certainty on full body cryopreservation, as there's technical risk and uncertainty. Share models for why it's possibly in scope, what we're testing. Good people are skeptical initially due to intuition it shouldn't work, but data quickly shifts views to reverse-engineer principles.
- Embryos can be reversibly cryopreserved.
- Work from cryopreservation community: John Bischof's group and Greg Fahy's (predating) show reversible cryopreservation in kidneys—rewarm, transplant into rat without other kidney, rat regains normal function after a month.
This demonstrates million-organ scale is academically tractable now.
The field struggled to attract resources to scale. Credit pioneers like Greg Fahy for tirelessly advancing vitrification despite neglect. In venture, it's about picking trends that feel weird or hard but technically viable. Whole body cryopreservation was conflated with extremes—people either love it unquestioningly or avoid as too sci-fi.
Longevity study has mainstreamed academically and in consumer interest over last 5 years; hope cryopreservation (tissues, neural, whole body) follows, becoming a respected field for next-gen professors without grant fears.
Patient experience: Waiting for life-changing surgery with no schedule—can't vacation, must stay near transplant center, within travel radius, or risk missing it. "Surgery center house arrest."
Matching: Last-minute after donor death—call around for available patients who can reach hospital quickly, no time for optimal match.
Making time not a variable changes the whole paradigm.
Dream: everyone has time for best decisions—surgeons don't operate exhausted after jet retrieval; schedule optimally. Current system is incredibly inefficient.
Curious about representing the molecular world compellingly—beautiful, colorful, fractal like light through tree branches, not flat textbook triangles and arrows. Make it accessible and exciting, like showing a tree to someone who's never seen one. Artistically and educationally valuable; most conceptualize it only after study.
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