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论文类型：期刊论文

发表时间：2015-06-13

发表刊物：MOLECULAR SIMULATION

收录刊物：SCIE、EI

卷号：41

期号：9

页面范围：691-698

ISSN号：0892-7022

关键字：molecular dynamics simulation; differential scanning calorimetry; trehalose; hydrogen bond; unfrozen water

摘要：Intensive studies have been conducted to determine the protective mechanisms of sugars that have proven beneficial to the biopreservation application. However, little has been known about the unfrozen water content that aqueous sugar solutions can possess when frozen at cryogenic temperatures. This study conducted calorimetric measurements to determine the unfrozen water content in frozen aqueous solutions of glucose, fructose, sucrose and trehalose of multiple concentrations. The hydrogen-bonding network in these solutions was characterised by molecular simulations. The experimental results showed that more water could be prevented from ice crystallisation in a more concentrated solution. Disaccharides, especially trehalose, are more effective than other protectants (e.g., glucose, glycerol and dimethyl sulfoxide) for detaining water in the unfrozen state. Moreover, it was found that, at molecular levels, there were more hydrogen bonds between sugar and water molecules in a more concentrated solution. From both macro- and microscopic perspectives, trehalose was demonstrated to be a much more effective cryoprotectant than others. This comparative study proved that the unfrozen water should be mainly attributed to hydrogen bonds between sugar and water in the mixture. Our findings will provide valuable information for determining the physical state of cryopreserved biomatrix and guiding the preparation of protective formulations.