| 摘要: |
| 在对关节软骨进行低温保存时，由于冰晶的生长而造成的热膨胀效应是其低温断裂的主要原因。本论文采用非等温热分析仪和修正的Avrami动力学方程，考察了分别添加不同浓度的四种醇类低温保护剂时，猪关节软骨低温保存过程中热力学及结晶动力学参数的变化。研究表明，软骨结晶峰随降温速率的增大而变宽，从而导致结晶越不完善；在﹣60~ 0 ℃温度范围，只有添加4.5 mol/L 1, 2 - 丙二醇时，其Avrami指数为4.156，冰晶以均相三维球晶方式生长。且与其他保护剂相比，1, 2 - 丙二醇保护效果最好。同时降温速率对结晶及热膨胀不同的影响结果也说明，低温损伤并不完全是由冰晶生长所决定,还与其胞外基质的缓冲作用有关。 |
| 关键词: 关节软骨 DSC热分析 低温保护剂 结晶动力学 |
| DOI： |
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| 基金项目:国家自然基金(50906056)资助项目。 |
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| Effects of Cryoprotectant on Thermal Expansion of Articular Cartilage during Freezing Process by DSC Method |
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Yu Huaxing, Li Daixi, Xu Yi, Zhou Guoyan, Liu Li, Zhai Zhen, Zhang Yan
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| (Institute of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology) |
| Abstract: |
| The thermal expansion caused by the growth of ice crystals is the main reason for low-temperature fracture of articular cartilage. With non-isothermal DSC method，this article investigated the thermodynamics and crystallization kinetics parameters of the pig cartilage.The results for four kinds of cryoprotectants were analyzed by the modified Avrami kinetic equations. It shows that the crystallization peak of the cartilage becomes wider with increasing cooling rate which lead to an incomplete crystallization; freezing from 0 ℃ to ﹣60 ℃，the value of Avrami is 4.156 when only 4.5 mol/L 1, 2 - propanedio is added. The crystallization would exhibit three - dimensional spherical growth on heterogeneous nuclei and contribute best protective effect compared to other cryoprotectants. While different effects of cooling rate on crystallization and thermal expansion also suggest that low temperature injury is not only determined by the growth of ice crystals，but also affected by the buffering of extracellular matrix. |
| Key words: articular cartilage DSC thermo analysis cryoprotectant crystallization kinetics |
