Tissue cryopreservation with inductive heating

[jordansparks]

This paper was published today:
http://stm.sciencemag.org/content/9/379/eaah4586.full
I have been skeptical that it might be possible to develop organ banking technology, and I have been vocal about my skepticism. After reading this paper, I will now admit that organ banking is theoretically possible -- just barely. I still think organ banking will be limited to certain kinds of tissues and will not be a panacea. There are just too many hard unsolved problems. Portable perfusion systems seem to solve the problems better.

If organ banking is theoretically possible, then I must now admit that suspended animation http://www.oregoncryo.com/suspendedAnimation.html is theoretically possible. This kills me, because I detest how suspended animation is always getting confused with cryonics. I state right at the top of our main page that we are not offering suspended animation. I would prefer to continue to refer to suspended animation as fictitious technology, but I won't.

This article
http://www.ibtimes.co.uk/organ-cryopres ... ay-1609149
mentions that the scientists involved acknowledged that their work might attract interest from the cryonics industry. But the scientists feel that it's not relevant because the hurdles are so huge that we are still looking at over 100 years of work before we could possibly perfect suspended animation. I agree wholeheartedly.

This paper will not change how we approach the preservation phase of cryonics. Will it generate enough interest to make cryonics more popular? No. Mainstream scientists already routinely cryopreserve tissue, and gradually scaling up to slightly larger tissue samples isn't going to change anything. Besides, this has nothing to do with cryonics, and most people correctly understand that intuitively. What most people unfortunately get wrong with intuition is the demonstrated fact that memories can already be preserved with current technology.

[gmcintir]

Jordan,

I am a 66 year old reluctant cryonaut mostly because one seems to have such a very small chance of being revived.I was very encouraged by this paper and decided to revisit cryonics to see what the take of the various cryonics organizations is. So I created an account and found your post here.

I am very discouraged to see your attitude on this work. It seems you find this paper threatening to your prior beliefs. I am at a loss to see how this work could threaten your organization.

I am interested in finding a cryonics organization saying something like "We find this work exciting and intend to investigate the pros and cons of offering an option to add these nanoparticles to our cryoprotectant "

I suspect the author with the 100 year quote is only trying to distance their work from the cryonics organizations as funding sources view cryonics as less reputable science.

Ask yourself... what if they succeed in reviving human sized organs in the next few years? What if they try the same technology on a small mouse and it works? All the current cryonauts will be unrevivable with that technology unless they have magnetic nanoparticles. The paper indicates the nanoparticles are easily flushed out so first indications are that the cons are minimal.

Maybe their are other cons, but you need an open mind and a lot of investigation to properly access this.

I think it would be in your best interests to examine your current position on this. A lot of potential customers are going to be interested in this technology until it is proven 'not' to work. They will be less interested in your stubborn negativism.

[jordansparks]

Thank you for your thoughtful post. On any given highly specialized topic like this, there are only a handful of scientific experts in the world who deeply understand the topic. They have spent their entire lives learning all the nuances of the topic from all angles. Deep understanding matters. Their opinions matter. Those experts have a general group consensus which must be respected. That's how science works.

My opinion is worthless because I'm not one of those experts on the topic. The mainstream scientific consensus of the experts is that suspended animation would take another 100 years or so to develop, and they specifically warn us against extrapolating this paper to suspended animation applications. So my views on the infeasibility of suspended animation simply follow the mainstream. As for whether they might revive organs, look to their responses for hints. They mention many hurdles. They mention that the application of this is currently very small tissue samples. They use words like "eventually" and "hopefully".

In summary, this paper is not the slightest bit threatening to me. It's just sort of irrelevant. What I do find threatening is the position that suspended animation is imminent. The scientific experts similarly find that idea threatening because there is no evidence for it, and it borders on pseudoscience.

[jordansparks]

There is a fallacy in argument called appeal to authority. It does not apply in this case because the authorities in question are experts on this topic. Now, I'm not aware of anyone having done a poll of the experts to see what their actual opinion of suspended animation is. If some of the experts turn out to have an opinion that suspended animation is only 20 years away, for example, then it would be acceptable to use that lower limit in your argument. I don't know of any, but feel free to let me know if you do. They would need to be recognized expert scientists in cryopreservation.

[tim]

What most people unfortunately get wrong with intuition is the demonstrated fact that memories can already be preserved with current technology.

Hi Jordan,

I was curious when I read this comment - what evidence is there that memories can be preserved with today's technology? My impression was that it's still unclear how memories are stored in the brain, so how could you verify that a cryonics technique preserves most memories?

[jordansparks]

It's been established for quite some time that memories are stored as changes in molecular structure of synapses. Yes, we're a bit vague on what that actually means, but it is almost certainly fundamentally correct. As we gain further understanding, we will no doubt refine and expand the model. Any neuroscientist would strongly disagree if you started claiming that memories weren't stored as changes in molecular structure of synapses.

So the goal is to preserve as much molecular structure of the brain as possible. Preserve everything, even if we don't fully understand how it works. Current technology can do this. The two major techniques are aldehyde fixation and cryopreservation. Of course, this is all very technique sensitive, and it can be done well or poorly. But it's a pretty basic fact that both techniques are able to preserve molecular structure of brains, including synapses. For fixation, in particular, scientists have been preserving brains for a very long time. They do so in order to study disease. We preserve for a different reason.

[tim]

One worry I have is that if you have to preserve everything, it would become impossible to verify. There can be many very minor changes, maybe some synapses changing length slightly but staying within the range of normal variation, and it’s hard to tell if they matter in aggregate. Even if brain preservation can work theoretically, many preservation protocols do not work. How could you tell that the brain preservation protocol you settle on works?

[jordansparks]

The only verification we can perform is to look at the ultrastructure under an electron microscope. We would only do this on non-patients. I would say it's fairly difficult to get good electron micrographs. So if the quality of the electron micrographs is good and is consistent across broad areas of the brain, then that is very strong evidence of a protocol that is preserving most memories. No preservation is going to be 100%. I'm thinking ranges of 60% to 90% would generally be considered mostly successful. I think it's clear from existing medical literature that brains can suffer some degree of damage and still retain some of the essence and memories of a person. Your suggestion that some synapses changing length slightly might be catastrophic seems to be a bit of a stretch.
Oh, and when I say to preserve everything, I mean just in case it's important. We don't know exactly which molecular structure is critical, so by simply trying to preserve everything, we maximize our chances. Most of the things we are preserving are probably extraneous, but they can provide correlation and redundancy.

[Aaron_Agassi]

As Samuel Johnson observed: "Nothing … will ever be attempted, if all possible objections must be first overcome." and that "so many objections might be made to everything, that nothing could overcome them but the necessity of doing something." I therefore pose the question: Is there precedent of success in any stopgap of simply trying to preserve everything indiscriminately, until better restoration is available? Archeological sites are often simply reburied for precisely this purpose. But are there better examples?