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4．5mol／L1，2-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。
The thermal expansion caused by the growth of ice crystals is the main reason for low-temperature fracture of articular carti- lage. With non-isothermal DSC method,this article investigated the thermodynamics and crystallization kinetics parameters of the pig carti- lage. 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.
出处
《制冷学报》
CAS
CSCD
北大核心
2015年第3期97-101,共5页
Journal of Refrigeration
基金
国家自然科学基金(50906056)资助项目
上海市"创新行动计划"国际科技合作(12430702000)
上海市重点学科(T0503和P0502)
上海市自然科学基金(12ZR1420400)
上海市教委科研创新项目(14YZ092)
上海市联盟计划项目资助~~
关键词
关节软骨
DSC热分析
低温保护剂
结晶动力学
articular cartilage
DSC thermo analysis
cryoprotectant
crystallization kinetics
