Pan Jiaji, Shu Zhiquan, Ren Shen, Gao Dayong
1 Department of Mechanical Engineering, University of Washington , Seattle, Washington.
2 School of Mechanical and Materials Engineering, Washington State University , Everett, Washington.
Biopreserv Biobank. 2017 Oct;15(5):404-409. doi: 10.1089/bio.2016.0096. Epub 2017 Aug 7.
In the rewarming process during cryopreservation, preventing ice recrystallization and thermal stress is important, especially for large tissues and organs. Uniform and rapid heating is essential in ameliorating the problem and maintaining the viability of cryopreserved biological samples. Currently, the most promising method is heating by application of electromagnetic (EM) waves, the effectiveness of which is dependent on the dielectric properties (DP) of the cryopreserved materials. In this work, the cavity perturbation method was adopted to measure the DP of cryoprotectant solutions. Based on the values of DP, the cryoprotectant solutions most amenable to EM heating can be identified. A system composed of a rectangular resonant cavity, a network analyzer, and a fiber optic temperature meter was implemented for the measurement. The DP of three cryoprotectant solutions during cooling to -80°C were measured and presented. The data can be used to optimize the rewarming process with the numerical method. The results show that a cryoprotectant solution consisting of 41% (w/v) dimethyl sulfoxide and 6% (w/v) polyvinylpyrrolidone has the highest dielectric loss for EM rewarming among the tested solutions. In addition, the developed DP measurement system could not only improve the EM heating in cryopreservation but also benefit hyperthermia or other therapies associated with EM waves.
在冷冻保存的复温过程中，防止冰重结晶和热应激非常重要，尤其是对于大型组织和器官。均匀快速加热对于改善该问题和维持冷冻保存生物样品的活力至关重要。目前，最有前景的方法是应用电磁波进行加热，其有效性取决于冷冻保存材料的介电特性（DP）。在这项工作中，采用腔微扰法测量冷冻保护剂溶液的DP。基于DP值，可以确定最适合电磁波加热的冷冻保护剂溶液。搭建了一个由矩形谐振腔、网络分析仪和光纤温度计组成的系统用于测量。测量并给出了三种冷冻保护剂溶液在冷却至-80°C过程中的DP。这些数据可用于通过数值方法优化复温过程。结果表明，在所测试的溶液中，由41%（w/v）二甲基亚砜和6%（w/v）聚乙烯吡咯烷酮组成的冷冻保护剂溶液在电磁波复温方面具有最高的介电损耗。此外，所开发的DP测量系统不仅可以改善冷冻保存中的电磁波加热，还对热疗或其他与电磁波相关的治疗有益。
