Hunter C Davis

Co-Founder and Chief Scientific Officer of @untillabs

[Hunter C Davis @huntercoledavis]

We’re building biology a pause button. Our challenge is deep across quantum physics, surgery, neuroscience, chemistry, molecular biology, machine learning, electronics, mechanics, and materials. Join us.

[Until @untillabs]

We’ve raised $100M+ to date, we are developing reversible cryopreservation for patients in need of donor organs, and we are hiring 🫀🎉🚀

[Hunter C Davis @huntercoledavis]

Here’s the blog post for those interested in learning more: https://t.co/8el3JZZngE

[Hunter C Davis @huntercoledavis]

I'm excited to introduce Mark 1, Until's electromagnet for rapidly rewarming organs from cryogenic storage temperatures. We set out to scale magnetic nanoparticle warming to human-scale organs while keeping the coil losses low enough for hospital use. Mark 1 produces a 900 kHz oscillating field at up to 40 kA/m with 7 kW of coil loss in a bore compatible with human-sized organs. This intersection of field, frequency, coil volume, and efficiency makes the system a first of its kind.

For organ rewarming, we reduce the field strength to 29 kA/m and bring the losses down below 4 kW. At these settings, we have been able to rewarm a vitrified pig kidney loaded with our in-house nanoparticles at 50 C°/min while consuming a total of less than 4 kW out of the wall. At this power, the device could run off of a common single phase 208V circuit. This 50 C°/min warming rate exceeds the critical warming rate required to outrun ice formation using our in-house cryoprotectant.

Mark 1 is just one example of the significance of audacious engineers and applied physicists for progress in reversible cryopreservation. If you're excited by pushing the frontier in hardware to improve human health, join our team.

[Until @untillabs]

We’re putting the “reversible” in Reversible Cryopreservation 🧡

Our latest post breaks down how our rewarming process works and shares new human organ-scale rewarming data we’re excited to finally show.

Check it out in the link below 👇

[Hunter C Davis @huntercoledavis]

@sierras_account @owl_posting Yep it works off of an inductor generating an oscillating magnetic field that flips the nanoparticles’ magnetic moments. Each of these flips releases a packet of heat, so high frequency means more packets released per second. Theory explainer here: https://t.co/8el3JZZngE

[Hunter C Davis @huntercoledavis]

@JerzySzablowski Congrats Jerzy! Well deserved.

[Hunter C Davis @huntercoledavis]

Let’s go!

[Jason Carman @jasonjoyride]

I am BEYOND excited to announce that after 1 year off, the best show in science & deep tech is BACK.

S3 returns this Saturday!

Bigger and better than before.

[Mikhail Shapiro (same on bsky) @mikhailshapiro]

Excited to co-found @Merge Labs!
TLDR: We’re developing a new paradigm for BCI using molecules instead of electrodes. If you’re excited about this and want to contribute in protein engineering, synbio, delivery, immunology, ultrasound, devices, neuroscience, or data/ML/AI, we’d love to hear from you.
https://t.co/YbMqQwePWv
https://t.co/XEG7p4NOCI
🧵

[Hunter C Davis @huntercoledavis]

@joejanizek 100% @owl_posting comes prepped and ready to dig in.

[owl @owl_posting]

i always kinda viewed the use-case of cryopreservation to be like...egg freezing and cryonics

turns out organ transport is a logistical and financial nightmare. sufficiently good cryopreservation would simply solve that. and maybe even improve how organ matching is done!

[Hunter C Davis @huntercoledavis]

Thanks @owl_posting for the great discussion! Really enjoyed the insightful questions and the opportunity to dive into the foundations and future of reversible cryopreservation.

[owl @owl_posting]

Bringing organ-scale cryopreservation into existence (Hunter Davis, Ep #6)

https://t.co/UQsWkjD0xp

(apple podcasts, spotify, and youtube links below)

This is an interview with @huntercoledavis, the CSO and co-founder (alongside @LauraDeming) of @untillabs, which you may also know by its prior name, Cradle. They are a biotech startup devoted to organ-scale cryopreservation. They raised a $58M Series A back in September 2025, and are backed by Founders Fund (especially interesting!), Lux Ventures, and others.

In this interview, we mainly talk about the engineering and scientific difficulties in the cryopreservation field, including some background details on their September 2024 progress report on neural slice rewarming, how they characterize tissue damage in their attempts to do kidney cryopreservation, the potential economics of future cryopreservation protocols, and lots more.

One of the most interesting conversations I’ve had in a long time. If any of this work seems interesting, Until Labs is actively and aggressively hiring!

Enjoy!

Timestamps:
0:00:00 – Clips
0:01:50 – Introduction
0:05:00 – Why don’t we have reversible cryopreservation today?
0:07:05 – Why is freezing necessary at all for preservation?
0:08:23 – Let’s discuss cryoprotectant agents
0:14:09 – Until Lab’s 2024 progress report on neural tissue cryopreservation
0:20:28 – How do you measure cryopreserved tissue damage?
0:22:34 – Translation across species
0:26:04 – Why was the cryopreservation storage time so short in the progress report?
0:30:47 – Nuances of loading cryoprotectants into tissue
0:37:03 – Let’s discuss rewarming
0:43:02 – What scientific problems amongst vitrification and rewarming keep you up at night?
0:45:58 – Why are there so few cryoprotectants?
0:48:11 – How can you improve rewarming capabilities?
0:53:03 – What are the experimental costs of running cryopreservation studies?
0:57:49 – What happens to the cryoprotectants and iron oxide nanoparticles after the organ has been thawed?
1:01:34 – Cryopreservation and immune response
1:03:25 – How do you filter through the cryopreservation literature
1:05:54 – How much is molecular simulation used at Until Labs?
1:10:04 – What are the (expected) economics of Until Labs?
1:14:49 – How much does cryopreservation practically solve the organ shortage problem?
1:17:04 – Synergy between xenotransplantation and cryopreservation
1:21:12 – How much will the final cryopreservation protocol likely cost?
1:21:58 – Who ends up paying for this?
1:23:28 – What was it like to raise a Series A on such an unorthodox thesis?
1:27:49 – What are common misconceptions people have about cryopreservation?
1:29:58 – The beginnings of Until Labs
1:34:07 – What expertise is hardest to recruit for?
1:39:27 – What personality type do you most value when hiring?
1:44:17 – Why work in cryopreservation as opposed to anything else?
1:46:26 – Until Lab’s competitors
1:49:30 – What would an alternative universe version of Hunter worked on?
1:51:33 – What would you do with $100M?

[Hunter C Davis @huntercoledavis]

https://t.co/P4kaCLEZFC

[Hunter C Davis @huntercoledavis]

Hi Boston friends! @untillabs is hosting events next week at Harvard and MIT. Come hear about our progress and current projects. RSVP links below.

[Hunter C Davis @huntercoledavis]

https://t.co/S9MrfjxW1I

[Hunter C Davis @huntercoledavis]

This is worth 30 min of your day. @jasonjoyride nailed it.

[Jason Carman @jasonjoyride]

After 10 months of work PLANET, our 1st sci-fi film, is officially live on our website!

[Hunter C Davis @huntercoledavis]

There's a lot that goes into the 'why now' for cryo, but our unique advantage is our team. These people have a deep sense of agency, incredible creativity, and complete commitment to our shared vision for the future of healthcare. Couldn't be prouder to come to work with them each day.

[Hunter C Davis @huntercoledavis]

We’re building biology a pause button. Our challenge is deep across quantum physics, surgery, neuroscience, chemistry, molecular biology, machine learning, electronics, mechanics, and materials. Join us.

[Until @untillabs]

We’ve raised $100M+ to date, we are developing reversible cryopreservation for patients in need of donor organs, and we are hiring 🫀🎉🚀

[Hunter C Davis @huntercoledavis]

@curiouswavefn @untillabs @foundersfund @Lux_Capital @Field_Ventures Great question! MD is a powerful tool, but nucleation is quite slow, so the atomistic simulation times are long. A lot of our computational work focuses on working around this constraint.

[Hunter C Davis @huntercoledavis]

https://t.co/fqaBHtEweF

[Hunter C Davis @huntercoledavis]

Starship launches evoke feelings akin to sports fandom, but your home team is humanity. It’s a wonderful lens into the experience of engineering at the frontier. Awe-inspiring demos remind the world why innovation is worth it.

[Casey Handmer @CJHandmer]

Can we please make more water? We have the technology to do mass scale desal and end Western water poverty forever. We don't have to fight over scraps. We don't have to dam up distant valleys. We don't have to suck the aquifers dry. We just need to end the ban on desalination.

[Adam Cohen @AdamEzraCohen]

I wrote an Op-Ed about the government's attacks on Harvard. Please share with anybody who thinks these attacks help anybody.
https://t.co/NvsZIn7XAE