The 2011 Cryobiology Conference

July 24-27 I attended the 2011 annual Society for Cryobiology conference in Corvallis, Oregon.

A number of the first presentations were concerned with means to *avoid* cryopreservation. Room temperature storage is much less expensive and troublesome, and improves ease of transport, especially in remote areas. One such technology “shrink wrapped” DNA in a glass  and another used trehalose to protect lipid membranes in a similar manner. Applied to cells, such technologies are viewed as a form of room-temperature vitrification.

Another researcher had successfully freeze-dried hematopoietic stem cells using trehalose and other additives without losing the ability of the stem cells to differentiate. Stress proteins in combination with trehalose allowed for desiccation of mammalian embryonic kidney cells without loss of viability. Late Embryogenesis Abundant (LEA) proteins also assist trehalose in dehydration tolerance.

Christoph Stoll showed that depleting red blood cell membranes of cholesterol can increase
trehalose uptake, but when I asked him in person about it, he said that the uptake was not enough to make much difference. Depleting cell membranes of cholesterol makes them more vulnerable to chilling injury, so I don’t think cholesterol depletion is a very good idea.

Masakazu Matsumoto spoke about some of the interesting anomalous properties of water.

Andrew Brooks spoke about the largest University cell and DNA repository in the world at Rutgers University.  They store DNA by plunging in liquid nitrogen.  He told me that 10 freezings and thawings does not impair DNA quality. That is encouraging for CI’s tissue/DNA storage program, because we plunge our samples into liquid nitrogen. Brooks gave data  showing that RNA is much less hardy in liquid nitrogen than DNA.

David Denlinger noted that HSP70 RNAi can block cold tolerance in insects. He also mentioned a Czech study which found that insect larva fed proline could survive liquid nitrogen. Perhaps we should be feeding proline to terminal cryonics patients.

In preparation for this conference, I had done a lot of reading on the subject of chilling injury and was hoping to question researchers on the subject. Steve Mullen showed a video of meiotic spindles dissociating at low temperature.

Spindles are a form of microtubules. Microtubules are known to dissociate at low temperature, but can spontaneously re-associate upon rewarming. But that would not be so beneficial when the microtubules are functioning as centrosomes because the reassembly would not be a reconstruction of the original structure. This is probably why cell division often  stops at low temperature.

Tiantian Zhang is one of the two candidates to become the new Society for Cryobiology President. Her field of study is cryopreservation of fish embryos and oocytes, which are especially vulnerable to chilling injury.

Fish are useful scientific models because they have a much simpler genome than mammals. 50% of endangered species are fish, but fish don’t get anywhere near the concern that pandas do. In both her lecture, and when I spoke to her in person, Dr. Zhang had apparently not learned any more than what was in her 2009 paper.

Why does reducing yolk content reduce chilling injury? Why is methanol the most non-toxic cryoprotectant for fish embryos, and so protective? If microtubule dissociation were a mechanism of chilling injury, it is indeed ironic that a 2006 Society of Cryobiology meeting presentation found that methanol causes proteolysis.

Kevin Brockbank spoke on the oxygenated hypothermic machine perfusion that he used to preserve pig livers at 4-6deg C for 12 hours. As a somewhat off-the-wall question, I asked him if he had assayed for chilling injury. This was off-the-wall because I have never heard of anyone assaying chilling injury. He responded that he had not, but that there were plans to use gene arrays to assay for chilling injury. This is like gene arrays to assay for aging — it requires deeper analysis, especially if chilling injury — like aging — is due to multiple mechanisms, the mechanisms are controversial, and no one mechanism is dominant. Northern wood frogs, arctic insects, and polar fish don’t have problems with chilling injury, although their adaptations include heat shock proteins and highly unsaturated cell membranes.

Much to my frustration, I have not had a good conversation with Peter Mazur (the uncrowned guru of cryobiology) since he got me to tell him I am a cryonicist several years ago. I have repeatedly asked him questions, and he has repeatedly been rude and dismissive. This year was different, for some reason. When I asked him about frozen water expansion contributing to mechanical damage he noted that cells could tolerate a 9% expansion without lysis even if freezing was intracellular. When I asked him how much dehydration cells could tolerate without damage, he said cells could lose all of the osmotic water (90% of cell water), and could lose more in freeze-drying with proper protectants (like trehalose). I was somewhat stunned by this answer, which takes no account of intracellular electolyte concentration increasing on dehydration. Next year I will be more optimistic about the possibility of talking with him, and I will prepare questions more carefully.

I spoke to Society for Cryobiology President John Crowe about his negative remarks concerning trehalose, in light of the fact that he is very aware of many of its benefits. John told me that a new method of manufacturing trehalose from starch is making trehalose as inexpensive as sucrose. If trehalose is used on bakery sugar, the sugar will not melt and run after a couple of days, as happens with sucrose. I mentioned to John that Robert Ettinger had just died. I had imagined that he might ask me to say a few words about the matter to the cryobiologists at their business meeting, but John treated the matter as a non-event, and I got the distinct impression that he would have preferred that I had not mentioned it.

At the business meeting it was noted that membership has dropped from close to 300 in 2008 and 2009 to just above 200 in 2011. There is concern that web access to the journal
CRYOBIOLOGY is becoming so easy that the incentives for membership have dropped. Or the global financial crisis is taking its toll on Society for Cryobiology membership. CRYOBIOLOGY journal impact factor has fallen to 1.830 from a high of 2.044 in 2002.

I appreciate being able to attend the business meetings, but one of the vehemently anti-cryonics cryobiologists gives me dirty looks. I have not been kicked-out yet, though, and decreasingly worry that I will be. A similar thought goes through my head as when I attend an Alcor meeting: “Spy in the House of Love.” But I really want the Society to prosper and grow, not be harmed, because I appreciate their good work (as with Alcor), even if they view me as a threat.

I had a brief chat with the cryonics-friendly Treasurer, who asked me when I think a cryonics patient will be reanimated. When I told him not less than 50 years, he said that a lot of surprising things can happen in 20 years. He is a more optimistic cryonicist than I am! At least as remarkable is that he is currently working with biotechnologists who are engineering scaffolds that can be used for growing organs from stem cells. That is a very cryonics-relevant project!

Every year I exchange a few words with Arthur Rowe (the cryobiologist who repeatedly compares cryonics to restoring a cow from hamburger — as he did in “Death in the Deep Freeze” – a comparison which probably originated with Peter Mazur). This year Arthur spent a lot of time hanging out with John G. Baust (the man who compared publishing cryonics science research with publishing Nazi hypothermia experiments). At the end of the conference I lost patience trying to catch Arthur alone, so I approached Arthur to say “hi”. Arthur said that he had seen on TV that Robert Ettinger had just died. He asked me about Robert’s educational credentials, and about my taking Robert’s place as CI President. Then he introduced me to John Baust. John was politely quiet, and said very little.

As with the 2010 Cryobiology Conference, I felt decreasingly paranoid as the meeting proceeded, but my level of paranoia was nonetheless very high near the beginning of this meeting. Overall, the amount by which I “came out” as a cryonicist was modest this year, and my softening of the hostility of cryobiologists to cryonics was modest this year compared to the previous one. The 2012 Society for Cryobiology Conference is scheduled to be held in Argentina.

At last, a sure-cold way to sell cryonics with guaranteed success!

A humorous romp through a promising new technique in aesthetic medicine from one cryonicist’s (warped) point of view.

Figure 1: Before cryopreservation (L) and after cryopreservation (R).

As everyone involved in cryonics for more than a fortnight is sadly aware, cryonics doesn’t sell. Indeed, if we were pitching a poke in the eye with a sharp stick, we’d more than likely have more takers than we’ve had trying to ‘market’ cryonics to the public. To see evidence that this is so, you need only wander around a shopping mall on a weekend and observe all the (painfully) stainless steel lacerated and brightly colored needle-pierced flesh sported by the young and trendy and increasing by the old and worn, as well.

Yes, it’s clear; we misread the market, to our lasting detriment.

It’s true that we’ve tried the ‘you’ll be rich when you wake you up line,’ and heaven knows we’ve beaten the ‘you’ll be young and beautiful forever’ line, well, virtually beaten it to death. And while people are certainly interested in great fortune and youth, both of these things share the same unfortunate shortcoming, namely that they are things that people either don’t have but want, or do have and don’t want to lose. As anyone who is really savvy at marketing will tell you, the best way to sell something is to promise (and preferably be able to deliver) that you can get rid of something that people have and really don’t want – something that is ruining the quality of their life, destroying their health, draining their pocketbook and, worst of all, making them really, really ugly.

So, it turns out that for onto 50 years now, we’ve missed the real selling point of cryonics that’s been there all along: IT WILL MAKE YOU THIN! Guaranteed!

Can such a claim be true? Well, surprisingly, the answer would seem to be an almost unqualified, “Yes!”

Recently it’s been discovered that adipocytes, the cells responsible not only for making you fat, but for making you hungry, as well, are particularly susceptible to a phenomenon in cryobiology that has proved a nettlesome (and only recently (partially) overcome) barrier to solid organ cryopreservation: chilling injury. Quite apart from freezing damage due to ice crystals forming, adipocytes are selectively vulnerable to something called ‘chilling injury.’ 1-5 Chilling injury occurs when tissues are cooled to a temperature where the saturated fats that comprise their cell membranes (external and internal) freeze. You see, saturated fat, which is the predominant type of fat in us humans, freezes well above the temperature of water – in fact, it freezes at just below room temperature. That’s why that big gash of fat on the edge of your T-bone steak is stiff and waxy when it is simply refrigerated, and not frozen.

Figure 2: Chilling injury is thought to result from crystallization of cell membrane lipids.

Chilling injury isn’t really well understood. In the days before both cryobiology and indoor heating, humans used to experience a very painful manifestation of it in the form of chilblains – tender swelling and inflammation of the skin due to prolonged cold exposure (without freezing haven taken place). In the realm of organ preservation it is currently thought that chilling injury occurs when cell membranes are exposed to high subzero temperatures (-5oC to -20oC), again, in the absence of freezing.

There is evidence that the lipids (fats) that make up the smooth, lamellar cell membranes undergo crystallization when cells are cooled much below 0 deg C. Since the crystals are hexagonal in shape and have a hole in the middle, this has the effect of creating a pore or hole in the membrane. Cells don’t like that – those holes let all kinds of ions important to cells keeping their proper volume and carrying on their proper metabolic functions leak in and out, as the case may be. This isn’t merely an inconvenience for cells, it’s downright lethal. Without boring you with technical details, it is possible to partially address this state of affairs in organ preservation by adjusting the ‘tonicity’ of the solution bathing the cells: oversimplifying even more, this means by increasing  the concentration of salts to a concentration higher than would normally be present

Figure 3: Contouring of the skin in a pig subjected to brief, subzero cooling of subcutaneous fat.

But, to return to our chilled adipocytes and the promise not only of weight loss, but of a fat-free future; adipocytes are killed, en masse, when their temperature is dropped to between 0 and -7oC. Within a few days of exposure to such temperatures they undergo programmed cell death (apoptosis) and within a couple of months they are phagocytized by the body; and all that ugly and unwanted fat is carted off to be used as fuel by the liver. Now the rub would seem to be that this effect is most pronounced when the temperature of the tissue is cooled to below the freezing point of water and held there – preferably for a period of 10 minutes or longer.

That sounds dire, doesn’t it? What about the skin, the fascia, blood vessels, and the other subcutaneous tissues that will FREEZE (in the very conventional sense of having lots and lots of ice form in them)? Well, the answer, as any long-time experimental cryobiologist will know (even if he won’t tell you) is: pretty much nothing. Way back in the middle of the previous century, a scientist named Audrey Smith and her colleagues at Mill Hill, England found that you could freeze hamsters ‘solid’ – freeze 70+% of the water in their skin and 50% of the water in their bodies – and they would recover from this procedure none the worse for wear. Similarly, those of us who have carelessly handled dry ice for a good part of our lives will tell you that we see parts of our fingertips turn into stiff chalky islands of ice all the time, with the only side effect being a bit of temporary numbness that resolves in a few days to a week – certainly a side effect well worth it to avoid the considerable inconvenience of rummaging around to find a pair of protective gloves.

Figure 4: The Zeltiq Cool Sculpting Cryolipolysis device.

But alas, we scientists (most of us, anyway) are not a very entrepreneurial lot, and so we never thought either of inventing the ZeltiqTM cryolipolysis system, or using ‘the thin-new-you’ as a marketing tool for cryonics.

Yes, that’s right; some very clever folks have found a way to make a huge asset out of a colossal liability – to organ preservationists, anyway. Around 2004 a Minneapolis dermatologist named Brian Zellickson, MD, who specialized in laser and ultrasonic skin rejuvenating procedures, made a not so obvious connection. Both laser and skin ‘face-lifting’ and skin ‘rejuvenation’ procedures rely on the subcutaneous delivery of injuring thermal energy to the tissues of the face, or other treated parts of the body (cellulite of the buttocks and thighs are two other common areas for treatment). These energy sources actually inflict a second degree burn in a patchy and well defined way to the subdermal tissues.

Now this may seem a very counterintuitive thing to do if you are trying to induce ‘rejuvenation’ or ‘lift’ a sagging face. But if you think about it, it makes a great deal of sense. As any burn victim will tell you, one of the most difficult (and painful) parts of recovery is stretching the highly contracted scar tissue that has formed as a result of the burn injury. Indeed, for many patients with serious burns over much of their body, the waxy, rubbery and very constricting scar tissue prevents the return of normal movement, and can lock fingers and even limbs into a very limited range of motion. Many burn victims must do painful stretching exercises on a daily basis to avoid the return of this paralyzing skin (scar) contracture.

And it must be remembered that aged skin – even the skin of the very old – can still do one thing, despite the many abilities it has lost with age, and that thing is to form scar tissue in response to injury. Thus, laser and ultrasonic heating of normal (but aged) skin induces collagen proliferation and large-scale remodeling of the skin. For all the bad things said about scar tissue it is still a remarkable achievement in that it does constitute regenerated tissue. Regenerated tissue which does the minimum that normal skin must do to keep us alive: provide a durable covering that excludes microbial invasion, and prevents loss of body fluids. By injuring the tissue just below the complexly differentiated layer of the dermis (with its hair follicles, sweat glands and highly ordered pigmentation cells) much of the benefit of ‘scarring’ is obtained without the usual downsides.

The injured tissues respond by releasing collagen building cytokines as well as cytokines that result in angiogenesis (new blood vessel formation) and widespread tissue remodeling. And all that newly laid down collagen contracts over time, tightening and lifting the skin – and the face it is embedded in. These techniques may justly be considered much safer versions of the old fashioned chemical face peel, which could be quite effective at erasing wrinkles and achieving facial ‘rejuvenation,’ but was not titrateable and was occasionally highly unpredictable: every once in awhile the result was disastrous burning and accompanying long term scarring and disfiguration of the patient’s face.

St some point Dr. Zellickson seems to have realized that the selective vulnerability of adipocytes to chilling offered the perfect opportunity for a truly non-invasive approach to ‘liposuctioning’ by using the body’s own internal suctioning apparatuses, the phagocytes, to do the job with vastly greater elegance and panache than any surgeon with a trocar and a suction machine could ever hope to do. Thus was invented the Zeltiq Cool SculptTM cryolipolysis machine.6

Figure 5: The cooling head of the Zeltiq devive equipped with ultrasonic imaging equipment and a suction device to induce regional ischemia and hold the tissue against the cooling surface.

The beauty of cryolipolysis is that it is highly titrateable, seems never to result to in excessive injury to, or necrosis of the overlying skin, and yields a smooth and aesthetically pleasing result. Not unjustifiably for this reason it is marketed under the name Cool SculptingTM. The mechanics of the technique are the essence of simplicity. The desired area of superficial tissue to be remodeled is entrained by vacuum in a cooling head equipped with temperature sensors, an ultrasonic imaging device, and a mechanical vibrator. The tissue in the cooling head is sucked against a conductive surface (made evenly conductive by the application of a gel or gel-like dressing to the skin) where heat is extracted from it. The tissue is cooled to a temperature sufficient to induce apoptosis in the adipocytes, while at the same time leaving the overlying skin untouched. The depth of cooling/freezing is monitored by ultrasound imaging and controlled automatically by the Zeltiq device.  At the appropriate point in the cooling process the tissue is subjected to a 5 minute period of mechanical agitation (massage) which helps to exacerbate the chilling injury, perhaps by nucleating the unfrozen fat causing it to freeze.7 When the treatment is over, the device pages an attendant to return to the treatment room and remove it.

The tissue under vacuum is also made ischemic – blood ceases to flow, and this has the dual advantage of speeding the course of the treatment by preventing the blood borne delivery of unwanted heat – and more importantly, by making the cooling more uniform, predictable and reproducible. It also has the effect of superimposing ischemic injury on top of the chilling injury which is something that seems to enhance adipocyte apoptosis. The whole treatment, in terms of actual cooling time, takes about 60 minutes. In the pig work which served as the basis for the human clinical treatments, the duration of treatment was only 10 minutes: but the cooling temperature was also an ‘unnerving’ -7oC. The degree of temporary and fully reversible peripheral nerve damage (that temporary numbness us ‘dry ice handlers’ know so well) was more severe at this temperature, although it resolved in days to a week or two, without exception.

As previously noted, cryolipolysis causes apoptosis of adipocytes and this results in their subsequently being targeted by macrophages that engulf and digest them. This takes time, and immediately after treatment there are no visible changes in the subcutaneous fat. However, three days after treatment, there is microscopic evidence that an inflammatory process initiated by the apoptosis of the adipocytes is underway, as evidenced by an influx of inflammatory cells into the fat of the treated tissues. This inflammatory process matures between seven and fourteen days after treatment; and between fourteen and thirty days post-treatment, phagocytosis of lipids is well underway. Thirty days after treatment the inflammatory process has begun to decline, and by 60 days, the thickness of interlobular septa in the fat tissue has increased. This last effect is very important because it is weakness, or failure of the interlobular fat septae that is responsible for the ugly ‘cottage cheese’ bulging that is cellulite. Three months after the treatment you get the effect you see below on the ‘love handles’ of this fit, and otherwise trim fellow. Thus, it is fair to say that Cool SculptingTM is in no way a misnomer.

Figure 6: Art left is a healthy, fit young male who has persistent accumulation of fat in the form of ‘love handles’ that are resistant to diet and exercise and the same man 3 months after cryolipolysis.

Does cryolipolysis really work? The answer is that it works extremely well for regional remodeling or sculpting of adipose tissue – those pesky love handles, that belly bulge around the navel, that too plump bum, or those cellulite marred thighs. So far it has not been used to try and ablate large masses of fat – although there seems no reason, in principal, why this could not be done using invasive techniques such as pincushioning the fat pannus with chilling probes, as is done with cryoablation in prostate surgery. However, this would be invasive, vastly more expensive, and likely to result in serious side effects.

And that was one of the really interesting things about the research leading up to FDA approval of cryolipolysis: it seems to cause no perturbation in blood lipids, no disturbance of liver function (the organ that has to process all that suddenly available fat) and no global alterations in immune function. It seems to be safe and largely adverse effect free. There is some localized numbness (as is the case in freezing of skin resulting from handling dry ice) but it resolves without incident with a few weeks of the procedure.8

So, all of this makes me wonder, since human tissues tolerate ice formation and respond to it in much the same way as they do to laser or ultrasound ‘rejuvenation’ (depending upon the degree of damage) a logical question is, “would it be possible to use partial freezing of the skin – just enough to provoke the remodeling response – as a method of facial rejuvenation?” It should be safer than a chemical people and it is, like laser and ultrasound therapy, titrateable.

Figure 7: “Gad darn it, this shiny gold stuff keeps getting into the silt I’m tryin to git out of this here river!”

Which returns me to the whole subject of cryonics: fat is very poorly perfused and it seems unlikely that things done to moderate or abolish chilling injury will be nearly so effective for the adipocytes in fat (if it they are effective at all). That means that we might well all come back from our cryogenic naps not only young, via the magic of nanotechnology and stem cell medicine, and rich via the miracle of compound interest (which none other than Albert Einstein once remarked was “the most powerful force in the universe”), but also THIN! For all these years organ cryopreservationists, like Fahy and Wowk, have been panning for the mundane silt of a way around a chilling injury9 all the while discarding the gleaming nuggets of gold that were persistently clogging up their pans.

We cryonicists should not repeat their error and should realize a good thing when we see it. Now, for the first time, we can credibly claim that if you get cryopreserved you’ll come back not only young and rich, but young and rich and beautiful and thin!

Methinks there must be very few in the Western World today, man woman or child, who can resist a product that has all that to offer – and which, by the way, bestows practical immortality in the bargain.

Ok, Ok, maybe we shouldn’t mention that last part about immortality; it might scare the children.

REFERENCES:

1)     Wiandrowski TP, Marshman G. Subcutaneous fat necrosis of the newborn following hypothermia and complicated by pain and hypercalcaemia. Australas J Dermatol 2001;42:207–10.

2)     Diamantis S, Bastek T, Groben P, Morrell D. Subcutaneous fat necrosis in a newborn following icebag application for treatment of supraventricular tachycardia. J Perinatol 2006;26:518–

3)     Lidagoster MI, Cinelli PB, Levee´ EM, Sian CS. Comparison of autologous fat transfer in fresh, refrigerated, and frozen specimens: an animal model. Ann Plast Surg 2000;44:512–5.

4)      Wolter TP, von Heimburg D, Stoffels I, et al. Cryopreservation of mature human adipocytes: in vitro measurement of viability. Ann Plast Surg 2005;55:408–13.

5)      Manstein D, Laubach H, Watanabe K, Farinelli W, Zurakowski D, Anderson RR. Selective cryolysis: a nivel method of noninvasive fat removal. Lasers Surg Med 2008;40:595–604.

6)     Avram MM, Harry RS. Cryolipolysis for subcutaneous fat layer reduction. Lasers Surg Med. 2009 Dec;41(10):703-8. Review. PubMed PMID: 20014262.

7)     Zelickson B, Egbert BM, Preciado J, Allison J, Springer K, Rhoades RW, Manstein D. Cryolipolysis for noninvasive fat cell destruction: initial results from a pig model. Dermatol Surg. 2009 Oct;35(10):1462-70. Epub 2009 Jul 13. PubMed PMID: 19614940.

8)     Coleman SR, Sachdeva K, Egbert BM, Preciado J, Allison J. Clinical efficacy of noninvasive cryolipolysis and its effects on peripheral nerves. Aesthetic Plast Surg. 2009 ul;33(4):482-8. Epub 2009 Mar 19. PubMed PMID: 19296153.

9)     Fahy GM, Wowk B, Wu J, Phan J, Rasch C, Chang A, Zendejas E. Cryopreservation of organs by vitrification: perspectives and recent advances. Cryobiology. 2004 Apr;48(2):157-78.