Vitrification enhancement by synthetic ice blocking agents
Vitrification enhancement by synthetic ice blocking agents
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DOI：
10.1006/cryo.2000.2243
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发表时间：
2000-05-01
期刊：
影响因子：
2.7
通讯作者：
Fahy, GM
中科院分区：
文献类型：
--
作者：
Wowk, B;Leitl, E;Fahy, GM
发现小浓度的合成聚合物聚乙烯醇（PVA）抑制水/冷冻保护剂溶液中冰的形成。随着分子量的降低，冰抑制作用提高。发现由20%乙酸乙烯酯组成的分子量为2kDa的PVA共聚物特别有效。PVA共聚物浓度为0.001、0.01、0.1和1%w/w时，在10 ml体积中玻璃化所需的甘油浓度分别降低了1、3、4和5%w/w。玻璃化所需的二甲亚砜浓度也分别降低了1、2、2和3%w/w。硼硅酸盐玻璃上的冰在与冷冻保护剂溶液接触时的结晶仅被1 ppm的PVA共聚物抑制。聚乙烯醇共聚物对乙二醇溶液的失透也有很强的抑制作用。目视观察和差示扫描量热仪的数据表明，PVA块冰主要是通过抑制异相成核。因此，聚乙烯醇似乎优先结合和冻结异质成核剂和/或新生冰晶的方式类似于在耐寒鱼类和昆虫中发现的天然抗冻蛋白。合成PVA衍生的冰阻断剂可以比防冻蛋白便宜得多，为通过玻璃化改善低温保存提供了新的机会。(C)北京大学出版社.
Small concentrations of the synthetic polymer polyvinyl alcohol (PVA) were found to inhibit formation of ice in water/cryoprotectant solutions. Ice inhibition improved with decreasing molecular weight. A PVA copolymer of molecular weight 2 kDa consisting of 20% vinyl acetate was found to be particularly effective. PVA copolymer concentrations of 0.001, 0.01, 0.1, and 1% w/w decreased the concentration of glycerol required to vitrify in a 10-ml volume by 1, 3, 4, and 5% w/w, respectively. Dimethyl sulfoxide concentrations required for vitrification were also reduced by 1, 2, 2, and 3% w/w, respectively. Crystallization of ice on borosilicate glass in contact with cryoprotectant solutions was inhibited by only 1 ppm of PVA copolymer. Devitrification of ethylene glycol solutions was also strongly inhibited by PVA copolymer. Visual observation and differential scanning calorimeter data suggest that PVA blocks ice primarily by inhibition of heterogeneous nucleation. PVA thus appears to preferentially bind and inactivate heterogeneous nucleators and/or nascent ice crystals in a manner similar to that of natural antifreeze proteins found in cold-hardy fish and insects. Synthetic PVA-derived ice blocking agents can be produced much less expensively than antifreeze proteins, offering new opportunities for improving cryopreservation by vitrification. (C) 2000 Academic Press.