Polymerization effect of electrolytes on hydrogen-bonding cryoprotectants: ion-dipole interactions between metal ions and glycerol.
Polymerization effect of electrolytes on hydrogen-bonding cryoprotectants: ion-dipole interactions between metal ions and glycerol.
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DOI：
10.1021/jp5105533
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发表时间：
2014-12-11
期刊：
影响因子：
--
通讯作者：
Elliott GD
中科院分区：
文献类型：
--
作者：
Weng L;Elliott GD
细胞膜可渗透的保护剂，例如甘油，已经有效地用于低温保存领域几十年，用于缓慢冷却和玻璃化应用。在后一种情况下，玻璃化组合物的玻璃化转变温度（Tg）是其应用的关键，决定了最终的储存条件。已经观察到，向甘油中添加一些电解质，例如MgCl 2，可以提高混合物的Tg，从而潜在地提供更多的储存条件灵活性。引起这些电解质的Tg增强行为的微观机制尚未得到很好的理解。目前的研究重点是甘油与各种金属氯化物混合的分子动力学模拟（即，NaCl、KCl、MgCl 2和CaCl 2），覆盖跨越液态和玻璃态的温度范围。分析了金属阳离子与甘油羟基之间的离子-偶极相互作用的特点。在氢键数量和寿命的背景下，通过添加离子，甘油分子之间的原始氢键网络的中断也进行了研究。发现二价金属阳离子通过强阳离子-偶极吸引力通过加强电解质/甘油混合物中的相互作用网络来显著增加Tg。与此相反，一价阳离子增加的Tg不显着，作为阳离子偶极吸引力仅略强于原来的氢键网络之间的甘油分子。在这些组合物中还观察到NaCl和KCl结晶的前体，这可能有助于弱Tg增强能力。在这项研究中阐明的Tg增强机制表明，二价离子的结构增强作用，可能是有益的保护性配方的设计，用于生物保护的目的。
Protectants which are cell membrane permeable, such as glycerol, have been used effectively in the cryopreservation field for a number of decades, for both slow cooling and vitrification applications. In the latter case, the glass transition temperature (Tg) of the vitrification composition is key to its application, dictating the ultimate storage conditions. It has been observed that the addition of some electrolytes to glycerol, such as MgCl2, could elevate the Tg of the mixture, thus potentially providing more storage condition flexibility. The microscopic mechanisms that give rise to the Tg-enhancing behavior of these electrolytes are not yet well understood. The current study focuses on molecular dynamics simulation of glycerol mixed with a variety of metal chlorides (i.e., NaCl, KCl, MgCl2, and CaCl2), covering a temperature range that spans both the liquid and glassy states. The characteristics of the ion–dipole interactions between metal cations and hydroxyl groups of glycerol were analyzed. The interruption of the original hydrogen-bonding network among glycerol molecules by the addition of ions was also investigated in the context of hydrogen-bonding quantity and lifetime. Divalent metal cations were found to significantly increase the Tg by strengthening the interacting network in the electrolyte/glycerol mixture via strong cation–dipole attractions. In contrast, monovalent cations increased the Tg insignificantly, as the cation–dipole attraction was only slightly stronger than the original hydrogen-bonding network among glycerol molecules. The precursor of crystallization of NaCl and KCl was also observed in these compositions, potentially contributing to weak Tg-enhancing ability. The Tg-enhancing mechanisms elucidated in this study suggest a structure-enhancing role for divalent ions that could be of benefit in the design of protective formulations for biopreservation purposes.
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影响因子：
3.2
作者：
FOX, TG;FLORY, PJ
通讯作者：
FLORY, PJ
DOI：
10.1021/je9801260
发表时间：
1998-11-01
期刊：
JOURNAL OF CHEMICAL AND ENGINEERING DATA
影响因子：
--
作者：
Hammadi, A;Champeney, DC
通讯作者：
Champeney, DC
影响因子：
3.8
作者：
Taylor, LS;Zografi, G
通讯作者：
Zografi, G
影响因子：
5.5
作者：
Hatcher, Elizabeth R.;Guvench, Olgun;MacKerell, Alexander D., Jr.
通讯作者：
MacKerell, Alexander D., Jr.
影响因子：
4.4
作者：
JORGENSEN, WL;CHANDRASEKHAR, J;KLEIN, ML
通讯作者：
KLEIN, ML