Alcor has implemented a new whole-body cryopreservation procedure which uses a new cryoprotectant solution, M22, licensed from 21st Century Medicine. The new cryoprotectant is perfused throughout the entire body using the same procedures required for glycerol cryoprotection; but while it cryoprotects the torso, arms, and legs, we are confident that it is also vitrifying the brain. The main difference, beyond the composition of the solution, is that neurovitrification can be done without separating the brain from the rest of the body.
This new whole-body procedure will now be standard for all members currently signed up as whole body, as well as for those whole body members who have executed an open option contract.
The important thing to realize about this process is what it cannot do. This is not whole-body vitrification, in the sense that the entire body is vitrified. Significant portions of the body do not cryoprotect sufficiently to vitrify, mostly because things like fatty tissue and skeletal muscle are not well-vascularized. This new procedure may not be as optimum for brain cryoprotection as a simple neuro procedure would be, because of the somewhat longer cryoprotection and cooling times. Conversely, compromises needed to protect the brain may lead to under-cryoprotecting the body, in less ideal cases. But the good thing to remember is that brain vitrification is now available to those who wish to remain strictly whole-body, and that the entire body is cryoprotected intact.
A significant amount of engineering work was done here at Alcor to ensure the proper use of M22. A new circulating chiller and perfusion circuit were needed, as were controlled-temperature enclosures for both the patient and the perfusion circuit to allow safe perfusion at temperatures well below the freezing point of water. The patient enclosure allows further cooling after cryoprotection, to at least -30 or -40 Celsius, reducing the hazards of temperature fluctuations while moving the patient into the next stage of cooling. The credit for this engineering work belongs to Hugh Hixon and Tanya Jones, who have done a wonderful job implementing the new procedure.
Those interested in neurovitrification and whole body cryoprotection will no longer have to face the sorts of compromises they did in the past, and we believe this is a significant advance in our capabilities. For those who would like to know more about M22, the composition and effects have been published in the scientific literature listed below [reference 1]. Electron micrographs of the ultrastructure of brain tissue vitrified with M22 have also been published [reference 2] and are available on the Alcor website at http://alcor.org/library/alcor-new-york-academy-of-sciences-paper/.
Further information and micrographs explaining the switch to M22 technology for all Alcor cases can be found on our website at http://www.alcor.org/library/new-cryopreservation-technology/.
As explained in reference 1, M22 has been shown to be compatible with high viability of tissue slices and with consistent survival of kidneys after transplantation. This allows the unprecedented vitrification of the human brain within the intact human body using a solution that is in principle capable of preserving tissue viability as measured by present-day methods. However, to be sure that the brain will vitrify in compromised human patients, Alcor currently must perfuse M22 for longer periods of time than those shown to preserve viability in model systems. In addition, M22 has not yet been shown to preserve the viability of the brain in model system studies.
Nevertheless, the use of M22 allows Alcor to come closer than ever to achieving the goal of in situ brain vitrification using perfusion conditions that preserve tissue viability by current standards. It keeps Alcor on the road to the possible, eventual attainment of this goal. [SVS/TJ]
(1) 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. http://www.21cm.com/pdfs/cryopreservation_advances.pdf
(2) Lemler J, Harris SB, Platt C, Huffman TM. The arrest of biological time as a bridge to engineered negligible senescence. Ann N Y Acad Sci. (2004) Jun;1019:559-63. Review. http://alcor.org/library/alcor-new-york-academy-of-sciences-paper/