Optimizing cell-cracking by ultrasound using an extended mathematical model

点击翻译按钮获取中文摘要

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