Comparative Study on Two Different Methods for Determination of Hydraulic Conductivity of HeLa Cells During Freezing.
Comparative Study on Two Different Methods for Determination of Hydraulic Conductivity of HeLa Cells During Freezing.
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两种不同方法测定 HeLa 细胞冷冻过程中水力传导率的比较研究。
DOI：
10.1089/bio.2015.0110
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Gao Dayong
中科院分区：
文献类型：
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作者：
Li Lei;Gao Cai;Zhao Gang;Shu Zhiquan;Cao Yunxia;Gao Dayong
背景：测定细胞膜的水导率对优化低温保存和冷冻手术方案非常重要。有两种不同的方法使用差示扫描量热法（DSC）来测量细胞和组织的冷冻反应。Devireddy等人提出了慢-快-慢（slow-fast-slow， SFS）冷却方法，利用具有渗透活性和无渗透活性的细胞在冷冻过程中释放热量的差异来获得细胞膜的水力导率和活化能。Luo等人简化了这一过程，并引入了单慢速（SS）冷却方案，该方案只需要一个冷却过程，尽管测定膜运输特性需要不同的细胞质。据我们所知，这两种方法在实验过程和对实验条件的要求方面还缺乏比较。本研究从上述几个方面对这两种方法进行了系统的比较。方法：采用前面提到的SFS和SS冷却方法，将模型拟合DSC数据，得到HeLa细胞的参考水力导率（Lpg）和活化能（ELp）。结果：SFS法测得液化石油气(lpg) = 0.10 μm/(min·atm), elp = 22.9 kcal/mol；SS冷却法得到的液化石油气(lpg) = 0.10 μm/(min·atm), elp = 23.6 kcal/mol。结论：两种方法测得的水运参数值具有可比性。换句话说，这两个参数可以通过比较同一样品的两个慢冷却过程之间的热释放，根据SFS方法得到。然而，SS方法需要分析具有不同细胞质的样品的热释放。因此，需要更多的实验时间。
Background:The measurement of hydraulic conductivity of the cell membrane is very important for optimizing the protocol of cryopreservation and cryosurgery. There are two different methods using differential scanning calorimetry (DSC) to measure the freezing response of cells and tissues. Devireddy et al. presented the slow-fast-slow (SFS) cooling method, in which the difference of the heat release during the freezing process between the osmotically active and inactive cells is used to obtain the cell membrane hydraulic conductivity and activation energy. Luo et al. simplified the procedure and introduced the single-slow (SS) cooling protocol, which requires only one cooling process although different cytocrits are required for the determination of the membrane transport properties. To the best of our knowledge, there is still a lack of comparison of experimental processes and requirements for experimental conditions between these two methods. This study made a systematic comparison between these two methods from the aforementioned aspects in detail.Methods:The SFS and SS cooling methods mentioned earlier were utilized to obtain the reference hydraulic conductivity (Lpg) and activation energy (ELp) of HeLa cells by fitting the model to DSC data.Results:With the SFS method, it was determined thatLpg= 0.10 μm/(min·atm) andELp= 22.9 kcal/mol; whereas the results obtained by the SS cooling method showed thatLpg= 0.10 μm/(min·atm) andELp= 23.6 kcal/mol.Conclusions:The results indicated that the values of the water transport parameters measured by two methods were comparable. In other words, the two parameters can be obtained by comparing the heat releases between two slow cooling processes of the same sample according to the SFS method. However, the SS method required analyzing heat releases of samples with different cytocrits. Thus, more experimental time was required.