Optimizing cell-cracking by ultrasound using an extended mathematical model

近年来，冲击波和冲击波技术被应用于医疗和生物技术行业，特别是体外冲击波碎石术、矫形器骨重建、药物基因治疗等。冲击波是一种传播速度大于声速的大压力变化波，其特点是：(1)单波和间断波，上升频率大；(2)持续时间约为微秒量级；(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技术，但细胞解体的基本机制尚未阐明。在本研究中，我们的目的是研究这一机理，并将冲击波技术应用于生物加工工业和医疗领域的细胞分解。在我们的研究小组中，利用冲击波和气泡对细胞进行崩解的研究，以及利用这些研究开发的新的生物过程和药物输送系统(DDS)。在…中本研究项目与德国埃尔兰根大学流体力学研究所合作，开展了以下三个方面的研究工作：(1)湍流剪应力(雷诺剪应力)作用下细胞的解体；(2)激波作用下细胞的解体与变形过程数学模型的建立；(3)激波与超声波联合作用下细胞内气泡的解体。研究结果表明：(1)湍流剪切流中细胞整合的剪应力阈值为1200~1400Pa，这一结果同样适用于人工器官的研制，如血泵和其他医用流动装置。(2)对球壳-水相互作用的数学模型进行了修正，研究了超声和冲击波对水中单个细胞和两个细胞的变形和损伤。(3)采用任意拉格朗日-欧拉(ALE)计算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。研究发现，内部气泡和微射流的不对称性对细胞的损伤有很大的影响，利用这些结果，未来细胞的崩解速度应控制在冲击波和超声波的作用下。较少

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