深低温保存对人类腘绳肌腱结构特性影响的实验研究

Differential scanning calorimetry study of human hamstring tendons after cryopreservation

[目的]应用差示扫描量热技术研究深低温保存后人类腘绳肌腱胶原蛋白的热稳定性变化。[方法]随机选取23例前交叉韧带损伤患者,术中从自体半腱肌腱、股薄肌腱各取3块体积约为3 mm×3 mm×1 mm肌腱,将半腱肌、股薄肌肌腱随机分成三组,分别于新鲜条件下、-80℃冷冻、-196℃液氮保存4周后进行差示扫描量热(DSC)测定,计算各组腘绳肌腱的变性温度、变性焓变及胶原蛋白三螺旋结构的百分比。[结果]-80℃冷冻保存和-196℃液氮保存半腱肌、股薄肌肌腱均较新鲜半腱肌、股薄肌腱变性温度及变性焓下降,胶原蛋白三螺旋结构数量减少(P<0.05),冰冻组较液氮组下降明显(P<0.05);半腱肌腱和股薄肌腱热稳定性比较无统计学差异(P>0.05)。[结论]深低温保存后腘绳肌腱胶原蛋白的热稳定性均有不同程度的下降,冰冻组下降更明显。

[Objective]To evaluate the collagen thermal stability of human hamstring tendons after cryopreservation by differential scanning calorimetry technology. [Methods]Twenty-three patients with anterior cruciate ligament injury（ACL） were enrolled randomly in this study.In the ACL reconstruction,we got 3 blocks of tendons with a volume of（3 mm×3 mm×1 mm） from each autogenous semitendinosus tendon and gracilis tendon respectively.All of the tendons were randomly divided into three groups：fresh group,frozen group and nitrogen group.The tendon blocks in fresh group were immediately sent to the laboratory.The other two groups were preserved separately at-80℃ fridge and-196℃ liquid nitrogen for four weeks and then sent to the laboratory.The peak temperature（Tm）,peak heat（Qm）,collagen denaturation enthalpy（ΔHm） were measured with differential scanning calorimeter（DSC） and the percentage of the collagen three helix structure（%） in each group. [Results]The values of frozen group and nitrogen group were significantly lower than fresh group in the peak temperature,peak heat,collagen denaturation enthalpy and the percentage of the collagen three helix structure（%）;further,frozen group was much lower than nitrogen group（P0.05）.There was no significant difference between gracilis tendons and semitendinosus tendons. [Conclusion]The thermal stability of collagen molecules in humans hamstring tendons decreased in varying degrees after different methods of low-temperature preservation.The thermal stability of humans hamstring tendons at-80℃ frozen preservation decreased more significantly than that of the tendons at-196℃ liquid nitrogen preservation.