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Scientists Have Found a Way To Rapidly Thaw Cryopreserved Tissue Without Damage (sciencealert.com)
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.
So Walt is coming back ?
"I've heard nonsense, compared with which that would be as sensible as a dictionary." Through the looking glass and what
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.
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."
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:
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."
Secession is the right of all sentient beings.
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?
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.
I can use this to thaw my steaks without accidentally cooking the edges in the microwave? Nice!
---- Den ene knappen er powerknapp, den andre er Bender voice knapp "Bite My Shiny Metal Ass"
The photos are legit. 50 ml is a sizeable thaw sample. My biochem circuits assesses this as a considerable advance for cryogenics. YES The trials stop at 50 ml, which these days means larger volumes failed. NO It does not allow a human brain mass to be thawed. But, smaller thaws are still great news. Basic research would see a tremendous boon if experiments can be performed with larger frozen sample sizes. A great number of potential medical treatments would become feasible with a 50x advance in cryogenic thawing. Some people here need an opinion reboot. This is exciting news!
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?
rajmohan_h@yahoo.com
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.
I thought ice crystals form during freezing -- how do they form when thawing?
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.
Thawing is great. How are you going to freeze the tissue without damage?
Become an Alaska Wood Frog (alternate article). They survive being frozen almost completely solid for 7 months at a time.
It must have been something you assimilated. . . .
And how do they "successfully wash the nanoparticles away from the sample after thawing" if it's injected throughout the whole tissue?
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.
"Sufficiently advanced satire is indistinguishable from reality." - [Tips: 1DrYakQDKCQ6y52z6QbnkxHXAocMZJE61o ]
Actually all the reports are that it tastes like pork, which is also rather explains why the attempts to wean cannibals off of eating humans worked when they provided them with pigs to raise and eat.
I've never heard of crystals forming when you warm a solid up to it's melting point.
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
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...
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 still cold.
const int one = 65536; (Silvermoon, Texture.cs)
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