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Title:
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Prospects for Vitrification of Whole Organs
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Author: |
G.M. Fahy
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Citation: |
Cryobiology 18 (1981) 617
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Abstract: |
Although most attempts at organ cryopreservation have involved freezing, there is an alternative. Vitrification would avoid all of the damaging effects of freezing except for exposure to very high concentrations of cryoprotective agents (CPAs), which would have to be perfused through an organ to permit it to be vitrified. The concentration of cryoprotectant required for vitrification, however, can be significantly reduced by the application of high hydrostatic pressure. For example, at 1000 atmospheres, a 44% w/v solution of dimethyl sulfoxide (D) and a 39% w/v solution of propylene glycol (P) will vitrify in bulk quantities at cooling rates applicable to whole organs, without any precautions to avoid heterogeneous nucleation. Also found was that the presence of CPAs actually enhances the ability of renal tissue to withstand high pressures, a phenomenon termed baroprotection. In the presence of 30% w/v D, P, or D + P, 1000 atm is tolerated very well. Unfortunately, 40% D and 30% P are toxic, but the toxicity of D can be greatly reduced by substituting urea or acetamide for a portion of the D. At 0°C, 30% D + 10% urea was almost nontoxic, and still higher total concentrations may be tolerated by using subzero temperatures, shorter exposure times to the CPA, and macromolecular stabilizers. The same methods might also be used to enhance pressure tolerance. Successful vitrification of kidney tissue, at least, may therefore be possible in the near future. (Supported in part by NIH Grant GM 17959 and BRSG No. 2S07RR05737.)
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