1.Institute of Biothermal Science and Technology,University of Shanghai for Science and Technology;2.Yin Feng Cryogenic Medical Technology Co,Ltd Shandong Jinan
The National Natural Science Foundation of China (General Program, Key Program, Major Research Plan)
目的 探究磁热复温对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，并通过组织染色及力学测试评价其复温效果。结果 （1）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；（2）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，较好地保存脐动脉的宏观和微观结构；（3）采用水浴和磁热复温后的脐动脉均出现不同程度的硬化，但后者弹性模量和极限应力与新鲜脐动脉无显著差异（P>0.05），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，磁热方式可以有效减小复温阶段的损伤，保证脐动脉较好的宏观、微观结构和生物力学特性。这些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 umbilical artery. Methods The vitrified umbilical artery was rewarmed by magnetothermal method and compared with the traditional water bath. The temperature distribution and thermal stress in the solution system were analyzed, and the rewarming effect was evaluated by tissue staining and mechanical test. Results (1) Compared with water bath rewarming, the temperature gradient ( =1.117±0.649℃) and thermal stress ( =0.026±0.016MPa) generated by magnetic rewarming were smaller, which could effectively avoid the occurrence of rupture and microcrack of umbilical artery, and the extracellular matrix, collagen fiber, elastic fiber and muscle fiber were evenly distributed. (2) The umbilical artery by magnetic rewarming had similar uniaxial tensile characteristic to the fresh group. There was no significant difference in elastic modulus and ultimate stress between the two groups (P>0.05), showing good elasticity and toughness. (3) The umbilical artery after water bath and magnetic rewarming showed different degrees of hardening, but the latter had the more similar stress relaxation and creep characteristics to the fresh umbilical artery. 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 mechanical properties.These results provide important evidence for cryopreservation of large tissues or organs such as umbilical artery.