10 replies to this topic

[nanothan]

I don't know if you've already commented on this, but what is your opinion of the CAS (Cells Alive System) freezing system, and do you think that similar methods could be used to enhance cryonics?

Also, could there be any use in cryonics for MRI or fMRI, or thermal cameras, or microwaves. The MRI or fMRI could be used to identify which areas have too much water, thermal properties, and the thermal cameras could be used again to visualize the thermal properties of the organ to help direct the perfusion to specific areas or direct the cooling or heating to specific areas to limit thermal damage. Microwaves or other electromagnetic could be used to heat the organs at a very quick rate, so that different cryoprotectants could be used. I don't know the physics behind this, but it seems anything where you can affect something without touching it, such as magnetic fields, electricity, electromagnetic rays, could possibly alter the way cryonics works and possibly make it more effective, and visualization such as fMRI and thermal cameras could be very useful for identifying and avoiding fracturing.

Also, computational models could be used to simulate different protocols and the affect that microwaves or magnetic fields might have on the outcomes.

Extremely high speed cameras or microscopes might also help, to build more accurate simulations.
What do you think about these possibilities (address which ever ones you feel like).

[Elus]

Perhaps a private message would have been more appropriate O_o?

[bgwowk]

The CAS system has been previously discussed.

http://www.imminst.o...802#entry242802

See also recent comments by Ben Best

http://www.imminst.o...s-alive-system/

All I can add is that it would be very strange if a static magnetic field influenced ice formation because water has no intrinsic magnetic moment. It is only slightly diamagentic. Also, the recent paper in the journal Cryobiology about this technology claimed improved cell survival after freezing in magnetic fields of comparable strength to the Earth's natural magnetic field, which makes no sense at all. I don't understand what this technology is doing, or whether it's really doing it.

Microwave and radiofrequency warming (electric field agitation of ions and electric dipole moments) are well-known in cryobiology. They are certainly useful for increasing the warming rate of vitrified tissue to avoid formation of ice (devitrification) during warming. There is extensive literature on the subject. However RF warming of vitrified tissue is a separate subject from CAS.

[nanothan]

Perhaps a private message would have been more appropriate O_o?

No it wouldn't because I wanted an in-depth answer which would be available to the forum, not a simple 5 second private question. If you don't know bgwowk is Brian Wowk, one of the world's foremost experts on cryobiology, not some random person.

The CAS system has been previously discussed.

http://www.imminst.o...ry242802</span>

See also recent comments by Ben Best

http://www.imminst.o...-system/</span>

All I can add is that it would be very strange if a static magnetic field influenced ice formation because water has no intrinsic magnetic moment. It is only slightly diamagentic. Also, the recent paper in the journal Cryobiology about this technology claimed improved cell survival after freezing in magnetic fields of comparable strength to the Earth's natural magnetic field, which makes no sense at all. I don't understand what this technology is doing, or whether it's really doing it.

Microwave and radiofrequency warming (electric field agitation of ions and electric dipole moments) are well-known in cryobiology. They are certainly useful for increasing the warming rate of vitrified tissue to avoid formation of ice (devitrification) during warming. There is extensive literature on the subject. However RF warming of vitrified tissue is a separate subject from CAS.

The disscussion so far seems to be relatively superficial. I get the feeling that there has not been much investigation of the potential of these technologies in cryobiology, since everyone only offers their opinion that it might work, or it might not work, rather than citing actual research.

My opinion is that with current cryoprotectants, virtually perfect preservation could be acheived by optimizing the procedures, and using the technologies I mentioned before. Lots of creativity and problem solving would need to be done, and LOTS of testing would need to be done, because diffrenent protocols might yeild results that were unpredictable beforehand.

Also, can you explain the graph that I attached? I got it from one of your videos, is it saying that there is a cryoprotectant which can acheive 100% presevation, if a warming rate of 10 degrees Celcius per minute could be acheived?

Attached Files

•  Untitled.png   351.98KB   3 downloads

Edited by nanothan, 16 November 2010 - 12:45 AM.

[Elus]

No it wouldn't because I wanted an in-depth answer which would be available to the forum, not a simple 5 second private question. If you don't know bgwowk is Brian Wowk, one of the world's foremost experts on cryobiology, not some random person.

Holy cow, I didn't know that. I just looked Brian up (Hi Brian ). It's pretty amazing to have people like this here.

You learn something new every day.

Edited by Elus, 16 November 2010 - 01:12 AM.

[eternaltraveler]

I was looking up some japanese articles a couple of months ago on the subject thanks to google's translation agent. It seemed like the system wasn't living up the hype and I stopped looking. I could probably find the reference again...

The CAS system has been previously discussed.

http://www.imminst.o...802#entry242802

See also recent comments by Ben Best

http://www.imminst.o...s-alive-system/

All I can add is that it would be very strange if a static magnetic field influenced ice formation because water has no intrinsic magnetic moment. It is only slightly diamagentic. Also, the recent paper in the journal Cryobiology about this technology claimed improved cell survival after freezing in magnetic fields of comparable strength to the Earth's natural magnetic field, which makes no sense at all. I don't understand what this technology is doing, or whether it's really doing it.

Microwave and radiofrequency warming (electric field agitation of ions and electric dipole moments) are well-known in cryobiology. They are certainly useful for increasing the warming rate of vitrified tissue to avoid formation of ice (devitrification) during warming. There is extensive literature on the subject. However RF warming of vitrified tissue is a separate subject from CAS.

[bgwowk]

The disscussion so far seems to be relatively superficial. I get the feeling that there has not been much investigation of the potential of these technologies in cryobiology, since everyone only offers their opinion that it might work, or it might not work, rather than citing actual research.

That's easily remedied for CAS, because I'm aware of only one journal article on the entire technology

http://www.ncbi.nlm....pubmed/20478291

I don't know what else to say other than what I've already said.

If you are referring to electromagnetic warming (which has nothing to do with CAS), there are nearly a dozen papers about that, and much more can be said. Electromagnetic warming using appropriate frequencies is certainly the best way to warm vitrified organs. It can heat them faster than conduction warming, thereby outrunning the tendency of vitrified materials to grow ice during warming (devitrification). We don't have an electromagnetic warming system in our lab yet, but we will because I believe it's essential for recovery of large organs from vitrification.

My opinion is that with current cryoprotectants, virtually perfect preservation could be acheived by optimizing the procedures, and using the technologies I mentioned before. Lots of creativity and problem solving would need to be done, and LOTS of testing would need to be done, because diffrenent protocols might yeild results that were unpredictable beforehand.

Indeed! However I can't begin to comment on your opinion without a clarification of what biological systems you are speaking of. Anticipating your response, let me just say that there is a big difference between what can be done with cell suspensions and tissue slices vs. whole organs.

Also, can you explain the graph that I attached? I got it from one of your videos, is it saying that there is a cryoprotectant which can acheive 100% presevation, if a warming rate of 10 degrees Celcius per minute could be acheived?

The chart to which you refer can be seen on page 161 of this paper

http://www.21cm.com/...on_advances.pdf

with a table of solutions on page 162. The solution in question is #10, which in the paper was moved to coordinates of 95% viability with a critical warming rate of 5 degC/minute based on better data. That's after 30 minutes of exposure at 0 degC, not actual vitrification and rewarming.

We can now get 100% viability in some tissue slices models after vitrification and warming using our best solutions. That would have been unthinkable 15 years ago, so there has been great progress. Work on protocols for reproducible success in organs continues. It's a complex problem because of the time required to exchange water for cryoprotectant inside cells when you can only access them via the vascular system.

[DeadMeat]

I haven't fully read it yet, but maybe this article could be interesting.
http://www.informawo...tent=a921710966

Effects of Electric and Magnetic Field on Freezing and Possible Relevance in Freeze Drying
M. W. Woo, A. S. Mujumdar

Application of an electric or magnetic field can significantly affect the freezing characteristics of water. A DC electric field will tend to induce ice nucleation at a lower degree of supercooling, and there is evidence to show that an AC electric field delays the onset of ice nucleation. Industrial research has shown that a magnetic field can be used to delay nucleation and to induce small, unclustered ice. Smaller ice crystals are essential in the preservation of the structure or bioavailability of frozen materials, particularly biological or food products. On the other hand, larger ice crystals facilitate faster freeze drying because it results in less vapor mass transfer resistance. The end part of this review introduces another application of magnetic field in the form of magnetocaloric freezers. This technology is a potential alternative to heat pump drying for commercial freezing and refrigeration.

[bgwowk]

I haven't fully read it yet, but maybe this article could be interesting.
http://www.informawo...tent=a921710966

Thanks for the reference. I was previously aware of the effects of electric fields on ice nucleation and anti-nucleation. However I purchased the article anyway to see what it said about magnetic fields. Disappointingly, the only references in the article concerning anti-nucleation effects of magnetic fields were the Owada (CAS) patents! The journal articles cited showed enhancement of nucleation by strong static magnetic fields (as happens with static electric fields), not suppression.

I found one other journal article today on the Owada (CAS) system. It's available for free on the web at

http://www.biomedres...nal/pdf/401.pdf

It does not state the absolute strength of the magnetic fields used, and shows no significant effect of the magnetic field on cryopreservation outcomes that I can see.

[nanothan]

My opinion is that with current cryoprotectants, virtually perfect preservation could be acheived by optimizing the procedures, and using the technologies I mentioned before. Lots of creativity and problem solving would need to be done, and LOTS of testing would need to be done, because diffrenent protocols might yeild results that were unpredictable beforehand.

Indeed! However I can't begin to comment on your opinion without a clarification of what biological systems you are speaking of. Anticipating your response, let me just say that there is a big difference between what can be done with cell suspensions and tissue slices vs. whole organs.

We can now get 100% viability in some tissue slices models after vitrification and warming using our best solutions. That would have been unthinkable 15 years ago, so there has been great progress. Work on protocols for reproducible success in organs continues. It's a complex problem because of the time required to exchange water for cryoprotectant inside cells when you can only access them via the vascular system.

The biological system I'm talking about is the brain since external artificial heart, lungs, and kidneys could be used to feed to brain blood. The rest of the body could be cryopreserved using less intensive methods if desired, but I wouldn't want to lose preservation quality of the brain by trying to preserve the whole body.

If 100% viability can be achieved in tissue slices, I presume this means that all the problems of whole organs stem from the size. I would like to help improve cryopreservation, as would others on this forum, even though I don't have that much knowledge, but in order to even think about solving any problems it's necessary to understand the problems, which I don't. So what exactly are the problems with preserving large tissues?

My basic strategy for solving the problems that come from size would be:
1. remove the brain and have it hooked up to a blood perfusion system, so that complete surgical access can be had.
2. perfuse it with high amounts of Cerebrolysin, which can combat all kinds of ischemia, as well as antioxidants, and growth factors.
3. use thermal cameras or MRI to find areas which are not being perfused with cryoprotectants properly.
4. have brain surgeons direct perfusion to specific areas.

How much success would these have?

Also, this website: http://www.scienceda...anic_chemistry/ has lots of inspiration for new ideas some of which could have application in cryobiology.

Could this http://www.scienceda...01109095324.htm have any benefit to cryonics?

Edited by nanothan, 18 November 2010 - 06:45 AM.

[nanothan]

I thought I would add the pdf of this paper http://www.scienceda...01109095324.htm in case anyone wants to read it. Although it probably won't help, since tetrahertz only penetrates like 1mm.

Attached Files

•  e203003.pdf   227.52KB   3 downloads

Edited by nanothan, 18 November 2010 - 08:22 AM.