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An Example of Present Work on Improving Vitrification


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#1 reason

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Posted 30 November 2015 - 01:16 PM


Interest in developing means of reversible vitrification for tissue preservation has been growing outside the cryonics community in recent years. This is a good thing for cryonics as an industry, as a greater interest in reversible tissue preservation in the broader research community will lead to both technological improvements that can be used by cryonics providers and a greater acceptance of cryonics. Cryonics is a legitimate approach to medical intervention where there is no other option for the patient, but despite greater public support for cryonics from scientists, there remains considerable and unfounded hostility within some portions of the research community. Hopefully this will change in the years ahead with meaningful progress towards the broader use of vitrification:

Researchers have discovered a new approach to "vitrification," or ice-free cryopreservation, that could ultimately allow a much wider use of extreme cold to preserve tissues and even organs for later use. Cryopreservation has already found widespread use in simpler applications such as preserving semen, blood, embryos, plant seeds and some other biological applications. But it is often constrained by the crystallization that occurs when water freezes, which can damage or destroy tissues and cells. To address this, researchers have used various types of cryoprotectants that help reduce cell damage during the freezing process - among them is ethylene glycol, literally the same compound often used in automobile radiators to prevent freezing. A problem is that many of these cryoprotectants are toxic, and can damage or kill the very cells they are trying to protect from the forces of extreme cold.

In the new research, the engineers developed a mathematical model to simulate the freezing process in the presence of cryoprotectants, and identified a way to minimize damage. They found that if cells are initially exposed to a low concentration of cryoprotectant and time is allowed for the cells to swell, then the sample can be vitrified after rapidly adding a high concentration of cryoprotectants. The end result is much less overall toxicity. The research showed that healthy cell survival following vitrification rose from about 10 percent with a conventional approach to more than 80 percent with the new optimized procedure. "The biggest single problem and limiting factor in vitrification is cryoprotectant toxicity, and this helps to address that. The model should also help us identify less toxic cryoprotectants, and ultimately open the door to vitrification of more complex tissues and perhaps complete organs."

If that were possible, many more applications of vitrification could be feasible, especially as future progress is made in the rapidly advancing field of tissue regeneration, in which stem cells can be used to grow new tissues or even organs. Tissues could be made in small amounts and then stored until needed for transplantation. Organs being used for transplants could be routinely preserved until a precise immunological match was found for their use. Conceptually, a person could even grow a spare heart or liver from their own stem cells and preserve it through vitrification in case it was ever needed.

Link: http://oregonstate.e...es-whole-organs


View the full article at FightAging
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#2 resveratrol_guy

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Posted 01 December 2015 - 12:03 AM

I would argue that organ vitrification is the single most important problem in medicine today, but it receives so little attention because it's seen as insurmountably complex. Personally, I think it's worth at least as much money as we throw at Halloween candy every year.

 

But in regards to this particular approach, I still wonder whether we're obsessed with apparent tissue quality at the expense of postrevival durability. In other words, do we really need to vitrify with chemicals at all? We have other potential options that don't involve such toxicity, or any headaches regarding asymmetric distribution of the agent.

 

In particular, firstly, would it not be a less daunting technical challenge to simply allow crystallization to occur, then repair that damage progressively during revival using stem cells? This would presumably fall well short of the difficulty of creating whole replacement organs, for which a few functioning examples nevertheless already exist. The brain, of course, cannot be replaced without mooting the point of the entire process, but a diffuse loss of half of neurons might be acceptable, not the least of which because co-frozen archives could compensate for some lost memories. (And would our memories really be so important in a world exponentially more advanced than at present, as opposed to novel plastic neurons ready to learn anew?)

 

Secondly, I have spent long hours wondering whether there is an electromagnetic or neuclear magnetic resonance approach that would help here, somehow using these techniques to dynamically thwart the formation of crystals during the plunge to the water vitrification temperature, resulting in a sort of amorphous ice, akin to window glass.

 

And third, is there a nuclear option, as in, can we freeze a cadaver so rapidly, presumably using a "nuclear freezer", so to speak, that even microscale crystallization fails? In theory, this is possible, because  physics does not allow instaneous crystallization of any substance. We just need to be fast enough. Liquid helium superfluid bath, perhaps? Water vitrifies at about -146C, and nitrogen liquifies at about -196C. So we can use conventional liquid nitrogen; the problem is to rocket down to -146C ASAP. At most, perhaps suffusing the tissues with nonbioactive metal ion complexes, analogous to the gadolinium contrast agents used in MRI, might help to buy enough of a time window to avoid crystalization.

 

In all, I think these approaches may offer better hope for revival, and entirely sidestep the questions of agent toxicity.

 


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#3 resveratrol_guy

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Posted 01 December 2015 - 04:10 PM

Here is a related thread on amorphous ice and supercooled water for tissue preservation. Looks like more progress has been made that I was aware of.


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