Thermal properties of ethylene glycol aqueous solutions
Thermal properties of ethylene glycol aqueous solutions
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DOI：
10.1016/j.crybiol.2004.02.003
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发表时间：
2004-06-01
期刊：
影响因子：
2.7
通讯作者：
Odagescu, V
中科院分区：
文献类型：
--
作者：
Baudot, A;Odagescu, V
通过将液体转变为无定形状态来防止冰结晶，玻璃化可以被认为是允许复杂的组织和器官冷冻保存的最合适的技术。这一过程需要在防冻剂化合物(如多元醇)中高度浓缩的低温保护溶液存在的情况下使用快速冷却速度。其中许多已经得到了深入的研究。它们的玻璃形成倾向和无定形状态的稳定性将使玻璃化成为现实，如果它们的生物毒性不降低它们的可用浓度，通常低于在可达到的热条件下玻璃化器官所需的浓度。幸运的是，研究表明，低温保护剂的混合物往往会降低低温保护剂的整体毒性，并且已经提出了各种含有乙二醇组分的有效组合。本文用差示扫描量热法测定了含40%、43%、45%、48%和50%(w/w)该化合物的水溶液的热性质。评估了玻璃的形成倾向和非晶态的稳定性作为浓度的函数。它们由避免冰结晶的临界冷却速率nu(Ccr)和在复温过程中防止过冷液态冰结晶所必需的临界升温速率nu(Cwr)给出。这些临界率是使用与之前相同的半经验模型计算的。结果表明，当乙二醇浓度增加时，平均临界冷速和升温速率显著降低，40%(w/w)时，V-Ccr=569，V-cwr=1.08×10(10)K/min；50%(w/w)时，V-Ccr=11，V-cwr=853 K/min。将这些结果与用相同方法得到的其他方言的相应性质进行了比较。乙二醇产率介于1，2-丙二醇和1，3-丙二醇之间。(C)2004 Elsevier Inc.保留所有权利。
Preventing ice crystallization by transforming liquids into an amorphous state, vitrification can be considered as the most suitable technique allowing complex tissues, and organs cryopreservation. This process requires the use of rapid cooling rates in the presence of cryoprotective solutions highly concentrated in antifreeze compounds, such as polyalcohols. Many of them have already been intensively studied. Their glass forming tendency and the stability of their amorphous state would make vitrification a reality if their biological toxicity did not reduce their usable concentrations often below the concentrations necessary to vitrify organs under achievable thermal conditions. Fortunately, it has been shown that mixtures of cryoprotectants tend to reduce the global toxicity of cryoprotective solutions and various efficient combinations have been proposed containing ethanediol. This work reports on the thermal properties of aqueous solutions with 40, 43, 45, 48, and 50% (w/w) of this compound measured by differential scanning calorimetry. The glass forming tendency and the stability of the amorphous state are evaluated as a function of concentration. They are given by the critical cooling rates nu(ccr) above which ice crystallization is avoided, and the critical warming rates nu(cwr) necessary to prevent ice crystallization in the supercooled liquid state during rewarming. Those critical rates are calculated using the same semi-empirical model as previously. This work shows a strong decrease of averaged critical cooling and warming rates when ethanediol concentration increases, V-ccr = 569 and V-cwr = 1.08 x 10(10) K/min for 40% (w/w) whereas V-ccr = 11 and V-cwr = 853 K/min for 50% (w/w). Those results are compared with the corresponding properties of other dialcohols obtained by the same method. Ethylene glycol efficiency is between those of 1,2-propanediol and 1,3-propanediol. (C) 2004 Elsevier Inc. All rights reserved.