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Novel Technology for Cryopreservation of Biological Tissue by Utilizing Ultrasonic lrradiation

利用超声波辐射冷冻保存生物组织的新技术

基本信息

批准号：
18560195
负责人：
TADA Yukio
金额：
$ 2.58万
依托单位：
Kanazawa University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18560195/
关键词：
Freezing Ultrasound Ice formation Ultrasonic cavitation Biological tissue 超音波キャビテーション

项目摘要

Freezing can slow down or stop some biological reactions for preserving biological cell. It is also true that the freezing is lethal to the living system. During freezing, the extra- and intra-cellular ice formation, osmotic water permeation through cell membrane, deformation of the cell and other behavior occur at microscale and they bring serious injuries connecting to life-and-death of living cell.A method to actively controlling crystallization is one of promising technique for cryopreservation. The object of this project is to study the effects of ultrasonic irradiation on ice formation during freezing of biological materials. In the experiments, agar gel was frozen under various irradiation methods of ultrasound at frequency of 28 kHz. The measurements of temperature and the microscopic observation of ice crystals by using fluorescent indicator were carried out.Firstly, it was found that ultrasound released the supercooling states, and reduced ice crystal size in the tissue. However, the fattning of ice crystal was observed by irradiation of higher ultrasonic power, since the cooling rate was reduced due to absorption of the ultrasonic wave. The ice crystal size in the tissue was clarified in relation to ultrasonic power and tissue size. Secondly, various irradiation methods were tested. It was found that the pulsed irradiation is useful for reducing ice crystal size, since the fattening of ice crystal due to absorption of ultrasonic wave is reduced. The mechanism of sonocrystallization in biological tissue was discussed in relation to ultrasonic power, on-off frequency and irradiation duration.

冷冻可以减缓或停止某些生物反应，以保存生物细胞。冷冻对生命系统是致命的，这也是事实。在冷冻过程中，细胞内和细胞外的结冰、渗透水透过细胞膜、细胞变形等行为都发生在微观尺度上，它们对活细胞造成严重的损伤，关系到活细胞的生死，主动控制结晶是一种很有前途的低温保存技术。本计画的目的是研究超音波辐射对生物材料冷冻过程中结冰的影响。在实验中，琼脂凝胶冷冻下的各种照射方法的超声波频率为28 kHz。利用荧光指示剂对冰晶进行了显微观察和温度测量。首先，研究发现，超声波可以解除组织中的过冷状态，减小冰晶的尺寸。然而，通过较高的超声功率的照射观察到冰晶的脂肪化，这是因为由于超声波的吸收而降低了冷却速率。组织中的冰晶尺寸与超声功率和组织尺寸的关系得到了澄清。其次，对各种辐照方法进行了试验。发现脉冲照射对于减小冰晶尺寸是有用的，因为减少了由于超声波的吸收而导致的冰晶的肥化。从超声功率、开关频率和照射时间等方面讨论了生物组织的声致损伤机理。