磁热复温对玻璃化保存脐动脉力学特性的影响

Effects of Magnetic Rewarming on Mechanical Properties of Vitrified Umbilical Artery

目的探究磁热复温对玻璃化保存的脐动脉组织形态以及生物力学特性的影响。方法采用磁热方式对玻璃化保存的脐动脉进行复温,与传统水浴复温方式进行对比,分析溶液体系内的温度分布及热应力,并通过对脐动脉进行组织染色及力学测试评价复温效果。结果与水浴复温相比,通过磁热复温产生的温度梯度和热应力较小,可以有效减小复温阶段热应力损伤,实现快速均匀的复温;磁热复温可以有效避免脐动脉出现断裂和微裂纹现象,并且复温后脐动脉细胞外基质、胶原纤维、弹性纤维以及肌纤维等结构分布均匀,可以较好地保存脐动脉的宏观和微观结构;采用水浴和磁热复温后的脐动脉均出现不同程度的硬化,其中后者弹性模量和极限应力与新鲜脐动脉无显著差异,具有相似的单向拉伸特性,表现出良好的弹性与韧性。结论相比水浴复温,磁热复温方式可以有效减小复温阶段的损伤,保证脐动脉具有较好的宏观、微观结构和生物力学特性。研究结果为脐动脉等较大组织或器官的玻璃化保存提供重要依据。

Objective To study the effect of magnetic rewarming on the morphology and biomechanical properties of vitrified umbilical artery. Methods The vitrified umbilical artery was rewarmed by magnetothermal method and traditional water bath. The temperature distribution and stress in the solution system were analyzed,and the rewarming effect was evaluated by tissue staining and mechanical test. Results Compared with water bath rewarming,the temperature gradient and thermal stress generated by magnetic rewarming were smaller,which could effectively reduce the thermal stress damage during the rewarming stage and achieve rapid and uniform rewarming. Magnetic rewarming could effectively avoid umbilical artery fractures and micro-cracks. After rewarming,the extracellular matrix,collagen fibers,elastic fibers and muscle fibers of the umbilical artery were evenly distributed,which preserved the macro and micro structures of the umbilical artery. The umbilical artery showed different degrees of hardening after water bath and magnetic rewarming,but the elastic modulus and limit stress of the latter were not significantly different from those of fresh umbilical artery,and the latter had unidirectional stretching characteristics similar to that of fresh umbilical artery,showing good elasticity and toughness. Conclusions Compared with water bath rewarming,magnetothermal method can effectively reduce the damage of rewarming stage,ensure the macroscopic,microscopic structure integrity of umbilical artery and better biomechanical properties. The research findings provide important references for cryopreservation of large tissues or organs such as umbilical artery.