Optimizing cell-cracking by ultrasound using an extended mathematical model

近年来，冲击波和冲击波技术在医学和生物技术领域得到了广泛的应用，特别是体外冲击波碎石术（ESWL）、骨科重建、药物基因治疗等。冲击波是一种传播速度大于声速的压力变化大的波，其特点是：（1）单波、间断波，上升频率大;（2）持续时间约为微秒级;（3）单位时间内能量传递大。利用这些特征，医学和工业需要新的技术和工艺，但细胞崩解的根本机制尚未阐明。本研究的目的是探讨这一机制，并将冲击波技术应用于生物过程工业和医学领域。本课题组开展了利用冲击波和气泡破碎细胞的研究，以及利用冲击波和气泡破碎细胞的新生物过程和药物传递系统的研究。在 ...更多信息 该研究项目与LSTM合作，（流体力学研究所;在德国埃尔兰根大学（University of Erlangen，Germany）的流动测量和分析中，研究了以下三个问题：（1）湍流剪切应力引起的细胞分裂（2）利用冲击波进行细胞破碎和细胞变形过程数学模型的建立，（3）使用冲击波和超声波使包含气泡的细胞崩解。（1）细胞在湍流剪切流中整合的剪切应力阈值为1200 ~ 1400 Pa，这一结果也适用于人工器官的研制，如血泵等医用流体装置。（2）修正了球壳-水相互作用的数学模型，研究了超声和冲击波作用下单细胞和双细胞在不同参数（膜厚度和杨氏模量）下的变形和损伤。（3）采用任意拉格朗日-欧拉（ALE）方法分析了含气泡的细胞在超声和冲击波作用下的变形过程，发现气泡内部的不对称性和微射流对细胞的损伤有较大影响，这为今后的细胞破碎研究提供了理论依据。少

Recently shock waves and shock wave technology are applied to medical and bio-technological industries, especially extracorporeal shock wave lithotripsy(ESWL), bone re-struction for orthpedics, gene therapy with drug. Shock wave is large pressure change wave whose propagating velocity is larger than sound speed, and its features are(1)single and discontinues wave with large rising frequency, (2)duration time is about micro second order, (3)large energy transfer per unit time. Using these features, new technology and technique for medicine and industry are needed, but the fundamental mechanism for cell disintegration has not been elucidated yet. In this study, our aim is to investigate this mechanism and apply the shock wave technology to disintegrate cell in the bioprocess industry and medical field. In our reaserch group, the study about the cell disintegration using shock wave and a bubble, and also the new bioprocess and drug delivery systems(DDS)using these have being developed. In … More this research project, with cooperation of LSTM(Institute of Fluid Mechanics ; in German)in the University of Erlangen, Germany, which has been in pride of flow measurements and analysis, the following three topics are investigated, (1)Cell disintegration by turbulent shear stress(Reynolds shear stress), (2)Cell disintegration and establishment of mathematical cell deformation process model using shock wave, (3)Disintegration of cell including a bubble using shock wave and ultrasonic wave. And the results for these in this projects are(1)The threshold of shear stress for cell integration in turbulent shear flow is from 1200 to 1400 Pa, and this result are also applicable to the development of artificial organs, for instance blood pumps, and other medical flow device.(2)Modifying the mathematical model of spherical shell-water interactions, deformation and damage of a single and two cells in water by ultrasonic and shock wave with changing parameter(thickness of membrane and Young modulus)are investigated.(3)Defomation process of a cell including a bubble by ultrasonic and shock wave is analyzed using arbitrary Lagrangian-Eulerian(ALE)computational method, and it is found that asymmetry of internal bubble and micro jet have large effects on the dmage of cells.Using these results, the cell disintegration rate should be controlled by shock wave and ultrasonic in future. Less