Scientists Have Found a Way To Rapidly Thaw Cryopreserved Tissue Without Damage (sciencealert.com) 94
schwit1 quotes a report from ScienceAlert: Researchers have developed a technique that allows them to rapidly thaw cryopreserved human and pig samples without damaging the tissue -- a development that could help get rid of organ transplant waiting lists. Cryopreservation is the ability to preserve tissues at liquid nitrogen temperatures for long periods of time and bring them back without damage, and it's something scientists have been dreaming about achieving with large tissue samples and organs for decades. Instead of using convection, the team used nanoparticles to heat tissues at the same rate all at once, which means ice crystals can't form, so they don't get damaged. To do this, the researchers mixed silica-coated iron oxide nanoparticles into a solution and generated uniform heat by applying an external magnetic field. They then warmed up several human and pig tissue samples ranging between 1 and 50 mL, using either their new nanowarming technique and traditional slow warming over ice. Each time, the tissues warmed up with nanoparticles displayed no signs of harm, unlike the control samples. Afterwards, they were able to successfully wash the nanoparticles away from the sample after thawing. The team also tested out the heating in an 80 mL system -- without tissue this time -- and showed that it achieved the same critical warming rates as in the smaller sample sizes, suggesting that the technique is scalable. You can view a video of tissue being thawed out in less than a minute here. The research has been published in Science Translational Medicine.
Frozen Riddick (Score:1)
So the technique shown in the documentary Chronicles of Riddick was indeed accurate.
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Re: Marinade (Score:5, Informative)
If only there was something you could click on that would take you somewhere else that had more information.
"The team admits that larger tissue - and even whole organs - will need to have the nanoparticles injected into them, rather than just sitting around them, to achieve the same uniform heating, but it's something they want to try next."
Re: Marinade (Score:3)
Why wouldn't microwave (RF dielectric) heating work in this case? That also is uniform, right? And can thaw even bigger organs better. Am I missing something?
Re: Marinade (Score:2, Funny)
No, it isn't "uniform", it is shaped something like A*sin(kx)*B*cos(my), that's why you have the rotating tray. Also, your ice crystal distribution is likely not very isotropic. Nanoparticles, on the other hand, may by magic or otherwise not form such clumps.
Re: Magic (Score:2)
TV dinners thin because microwaves don't heat deep (Score:2)
If you put a large potato in the microwave for two minutes, then cut it open, you'll find that the surface is hot and core is cool. The microwaves penetrate about 1/4th to 1/2 inch into the food. (More at the surface, reducing with depth). That's one reason TV dinners have the food spread out so thin - for even heating. That 1/2" of microwave heating is *more* even than a conventional oven, which heats only the surface.
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Microwave heating isn't uniform. It's like how your mobile phone signal gets worse the deeper you go into a building. The energy is reflected or absorbed by the walls and other stuff between you and the transmitter.
Food designed for microwave heating is designed to allow circulation of water and steam, and the microwave usually rotates the whole thing too. If you just take something out of the freezer, heat it without the rotating tray for a bit, you will find that the outside is warm and the inside is stil
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And how do they "successfully wash the nanoparticles away from the sample after thawing" if it's injected throughout the whole tissue?
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presumably they would be injected into the major arteries during the cryopreservation process. They could then be (largely) washed out the same way they were put in. Some would likely be left behind, but hemosiderin deposits are found in all kinds of tissues without obvious problem.
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Freezing damage (Score:2)
Thawing is great. How are you going to freeze the tissue without damage?
Re:Freezing damage (Score:5, Interesting)
There are a few ways of freezing samples without creating ice crystals. Part of the trick is to freeze it *fast*. But water is still a problem, becuase even with super rapid freezing, overtime the crystals will restructure into sharp ice. Bad. Nitrogen would seem the obvious, but it tends to boil at the contact point leaving pockets of gaseous nitrogen to slow down the penetration of cold leaving the centres of samples to slowly ice and form crystals. Isopentane doesnt have the low boiling point issue so it works a lot better Glycerine is often used in storing cell cultures. And so on.
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Most liquids shrink when they freeze, though all Earthly life depends on water being the exception. Could we perfuse organ tissue with one of those blood substitute liquids before freezing, if we can choose one that does not expand when frozen? As a bonus, could we add the thawing nanoparticles to the fluid before perfusing the organ?
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Actually, the damage is not caused by expansion, but by crystallization. So you need to add something that creates an amorphous solid ice when mixed with water, or at least far smaller ice crystals.
In nature... (Score:5, Informative)
So you need to add something that creates an amorphous solid ice when mixed with water, or at least far smaller ice crystals.
Which is exactly the technique used by some fishes that can survive in the ice :
they secrete some sort of anti-freeze in their bloodstream which prevent big ice crystals to form.
Re:Into vs around (Score:1)
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The claims they're making implies that's a solved problem. /me shrugs
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No, the problem is in the freezing, fractures happen to samples bigger than 3cm across. It's why cryopreservation of dead humans is a farce, they're made into a mass of meat nuggets by the process.
Not a solved problem at all.
Re: Freezing damage (Score:4, Informative)
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The MÄori did call roasted human "the long pig" after all. But they insisted on fresh, never frozen.
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No, the problem is in the freezing, fractures happen to samples bigger than 3cm across. It's why cryopreservation of dead humans is a farce
So.... How about putting the samples in a vacuum chamber, and reduce the air pressure in order to Make the freezing point of water lower,
then super-chill the tissue under lower and lower pressures, until it is cold enough to preserve the tissue without freezing the water, causing it to become solid crystals.
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Right so... they've solved it, or the news is faked? The demo is thawing meat without damage.
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you saw the size of the sample in the article, 50 mL? what I said is still very much a problem.
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Re:Freezing damage (Score:5, Informative)
Thawing is great. How are you going to freeze the tissue without damage?
Become an Alaska Wood Frog [nationalgeographic.com] (alternate article [latimes.com]). They survive being frozen almost completely solid for 7 months at a time.
Walt Disney (Score:2)
So Walt is coming back ?
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No walt isn't, after he and his film crew tossed us off the cliff, we located him and I gnawed thru his left kidney and thyroid.
Worst two week ice cream headache ever. But he's gonna be real surprised.
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Does this mean that the underground organ trafficking black market will collapse very soon?
No, it means that packinghouses in China will cash in by freezing prisoners' organs so they can be stored and then flown anywhere for transplant.
Restoring tissues and organs (Score:5, Funny)
I know it was demonstrated awhile back that a rabbit kidney could be cryopreserved and then restored to function.
Seriously, the longer I live, the more it seems plausible that one day it will be possible to cryopreserve a human brain and restore it to function later. One day human lifespan may be greatly extended in a way that looks like this [alcor.org]:
McCoy: "He's dead, Jim."
Kirk: "Bones, do something!"
McCoy: "Sorry, Jim, there isn't anything I can do."
KirK: "Why?"
McCoy: "Because he's dead."
Kirk: "How do you know he's dead?"
McCoy: "Because there's nothing I can do."
Kirk: "Because he's dead?"
McCoy: "That's right."
Kirk: "But I was talking to him just one minute ago!"
McCoy: "Dammit Jim, I'm a doctor not a spiritual medium! I can't bring back the dead anymore than I can cure a common cold."
Spock: "Doctor, we could take him back to the ship, dissolve any blood clots, restore circulation, and restore homeostasis by molecular repair. He could fully resume duty within days."
McCoy: "Spock, leave doctoring to doctors! What this man needs is a decent burial."
So.... (Score:3)
I can use this to thaw my steaks without accidentally cooking the edges in the microwave? Nice!
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A human brain mass is not the gold standard! (Score:5, Insightful)
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Obvious deep space travel use (Score:2)
Ok, even if this only becomes partially successful, you could imagine it being used for an attempt by desperate individuals (or a desperate world) to send people to another star.
If only 25% of the individuals frozen, revived successfully after a centuries long trip, would it be worth it? And this is assuming the nanoparticles infected into them were non-toxic. I guess if the literal survival of the human race depended on it (I believe a third of the colonists at Plymouth didn't make it through the first w
I'd do it right now (Score:2)
In fact I'd happily pay for the privilege to go...
There are quite a lot of people who would be willing to do the same thing today. Maybe get the process a bit more stable but a 25% chance sounds fine to me.
But not "time travel" (Score:2)
The X-Files [wikipedia.org] had an episode where a rapid freezing agent was the key enabler to allow people to time travel, but of course that means a future self will come back to kill you because time travel is so messed up, so it never really happens... Or does it?
When do ice crystals form? (Score:4, Interesting)
I thought ice crystals form during freezing -- how do they form when thawing?
Re:When do ice crystals form? (Score:4, Informative)
At a certain temperature water freezes solid almost instantly, which means its molecules don't have time to rearrange themselves into a crystal lattice. This kinda makes it more fragile but that's not part of this answer. What is part of it is that as the boundary of heat penetrates the frozen object, there is a small war of temperatures. One side is hot fading to cold, the other is cold slowly warming. On the cold side of the boundary ice turns to water, expanding the boundary enough that the water next to the much colder than normal ice can then turn back into ice, much more slowly (comparative to the flash freezing process from before), and form crystals. They aren't large crystals, but human cells aren't large either.
An example of this is having damp fingers after refilling an ice tray and using a paper towel to dry your hand, then grabbing an ice cube and finding that it freezes to your fingertip. Your finger is warm, the thin coating of water on it is at skin temperature, between 65-75 degrees F, but the ice is cold enough to freeze the water on your skin almost instantly and stick to you for a few moments before your body's heat overcomes it and melts the water again.
What the nanoparticles here are doing is warming the entire object at once, rather than heating it from the inside out or outside in. Since there is no temperature boundary, there is no chance for the water to re-freeze.
Well how cool would this be.. (Score:2)
-Ok, samples 1-50 show perfect integrity after thawing...
* Well now what can we test this on?
-Dave, BRING ME THE HEAD OF WALT DISNEY!!!!
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Common misconception. Disney was not cryopreserved. Or if he was, it was not by some big company, it was done by some Mickey Mouse operation...
As an expert in this field (Score:2)
That was not without damage, though.
Barring Liquid Crystals (Score:3)
Rather liquids are kind of the opposite of a crystaline structure last time I checked.
But they do form when freezing, and that's why they try to do the really rapid glassification as it is an attempt to stop all crystal formation, or at least limit their size to very small. Those crystals can and do puncture cell walls, which means that cell is a goner. Lose enough of those, or some really critical ones, and the creature is toast, end of game, don't even bother to thaw it out.
Now we do have some creatures that can survive freezing conditions, but they've got some tricks that aren't applicable to humans without some serious genetic modifications we don't even know how to do. The short version is they tend to flood their blood and cells with a type of antifreeze so there are less or smaller ice crystals so more of their tissue survives. Still, they can be killed by freezing. When you get to the single cell or other very simple types, it's a lot easier for them to survive since their structures are simpler and their cells less specialized.
I do find the idea of using induction to warm the material interesting, but having that material appropriately spread out in a living creature before freezing seems to be a rather difficult proposition. That's assuming those nano particles don't themselves cause an issue. I don't see it being done after freezing anymore than I see someone distributing sugar into an ice cube without pulverizing it. That would rather defeat the point.
Anyhow, interesting idea, but still, WTF
Bummer, Bob. (Score:2)
Bummer, Bob.
Yeah, sorry; we were unable to get you out of the red light ticket. So one of your kidneys? Yeah, it's going to the organ bank.
This give new meaning to (Score:2)
Transplants (Score:2)
It seems that most commenters think about the scifi theme of thawing entire human bodies after cryo-preservation.
To me, it rather seems that a first application would concern transplants - more organs could be collected, and be kept around much longer than presently possible, to be transplanted later into patients really needing them (as opposed to being able to pay for them).
It could help with reducing waiting lists, enable more people in need to survive, with less crime revolving about collection of organ
Nanoparticles not needed for stronger magnet? (Score:2)
With a switchable magnet orders of magnitude stronger, you should be able to heat the hydrogen atoms directly, should you not? Here's a pic of a live frog levitating in a 16 Tesla magnetic field.
http://www.ru.nl/hfml/research... [www.ru.nl]
Great news for the Red Sox! (Score:2)
Hitler (Score:2)