醇类保护剂对猪软骨低温膨胀过程的作用

Effects of Cryoprotectant on Thermal Expansion of Articular Cartilage during Freezing Process

在对关节软骨进行低温保存时,常常会观察到低温断裂现象,然而对其生物力学性能的低温损伤机理至今仍不甚明确。采用热机械分析仪,在0℃到-60℃的温度范围内,不同慢速降温速率下,研究了四种醇类低温保护剂对猪关节软骨热膨胀行为的影响。结果表明:降温过程中,软骨细胞外存在的热膨胀现象,导致关节软骨产生了较大热应力;当添加浓度较高的乙醇和乙二醇时,降温速度越快,关节软骨产生的热应力越大,因而,降温速度越慢,越适合关节软骨的低温保存;而添加1,2-丙二醇和甘油时,则存在最佳降温速率(3℃/min),最佳降温速率下的软骨产生的热应力最小。同时分析结果表明,四种醇类低温保护剂中,甲基化高的醇类保护剂的热膨胀保护效果更优。

Low-temperature fracture？ is often observed during the low-temperature preservation of articular cartilage. However,the biomechanical damaging mechanism of cryopreservation is still unclear. During freezing from 0 ℃ to -60 ℃,Thermol Mechanical Analysis （TMA） was used to investigate the effects of 4 kinds of cryoprotecants with different concentrations. The results indicate that： （1） the cartilage produced a great thermal stress due to the extracellular thermal expansion during the cooling process;（2） when adding a higher concentration of ethanol and glycol,the faster the cooling rate,the greater thermal stress the articular cartilage will produce,and thus,slower cooling rate is more suitable for the cryopreservation of articular cartilage;（3） while adding 1,2 -propylene and glycerin,there is an optimal cooling rate （3 ℃/min） and it produces cartilage a minimal thermal stress. Moreover,cryoprotectants of higher methylation will contribute better protective effect to the thermal expansion among the 4 kinds of alcohols.