肾脏器官冷灌注过程三维温度场重构及微观实验研究

发布时间：2018-03-17 01:27

本文选题：冰温　切入点：肾脏器官　出处：《天津商业大学》2014年硕士论文　论文类型：学位论文

【摘要】：冰温保存技术是近年来一种新的保存技术，本文以延长复杂生物器官保存时间为背景，利用生物、热物理、临床医学等多学科相结合的方法，对生物组织冰温保存过程中的热质传递过程进行研究，研究内容有组成生物体最基本的单位——细胞的低温保存和整体器官的冰温保存和移植，通过与临床现行的保存方法进行对比，在微观层面和宏观层面揭示冰温延时保存技术应用于复杂生物组织的传热传质机理。本文以肾表皮细胞为研究对象，利用显微镜图像分析方法，研究了其在不同温度、不同渗透压下的渗透特性，其中包括细胞的非渗透体积、细胞膜对水和低温保护剂的渗透系数等。结果表明，在等渗溶液中，细胞的平均等渗体积Viso=2472.58μm3；非渗透体积Vb=0.22Viso；观察细胞在高渗低温保护剂溶液中的渗透响应，利用两参数模型，得到了不同温度下在二甲基亚砜、乙二醇、甘油溶液中肾表皮细胞对水的渗透系数（Lp）、对低温保护剂的渗透系数（Ps）及活化能（Ea）；通过对比细胞在冰温和常温下保存的存活率，得到了针对肾表皮细胞的最佳保存温度。在生物传热模型中，多孔介质模型能够描述肾脏组织的特征，多孔介质的骨架由细胞构成，而用于血液等体液流通的通道由毛细血管及淋巴管等构成。在研究多孔介质模型的过程中，需要将肾脏的物性进行测定。本文对肾脏的两项最基本的特性参数，即孔隙率和渗透率，进行了研究。结果表明，猪肾脏的孔隙率为Φ=15.64%，渗透率为K=14.5μm2。该结果为肾脏冷灌注过程的数值模拟提供了实验基础。离体肾脏的冷灌注过程作为冰温保存的首要环节，对该过程肾脏温度场变化的研究具有重要的临床价值，，在肾脏冷灌注过程中，对肾脏表面温度和内部温度进行了全面的监控。在此实验基础上，利用血管铸型对肾脏的动静脉血管和肾脏外形进行三维重建，得到肾脏的物理模型，并导入Fluent流体动力模拟软件中，以管内层流流动模型和肾脏组织多孔介质模型相结合的方式，对肾脏冷灌注过程的三维温度场进行重构。将模拟结果与实验结果对比，探索冷刺激作用下，灌注作用引起的肾脏温度变化，并对温度场模拟结果进行了应用研究。最终，以上述研究为基础，对猪进行了自体移植临床实验，将肾脏在-0.8℃下进行36小时的冰温保存后，重新植入体内，移植后第四天，各项生理指标恢复正常。该实验验证了冰温保存方法可以抑制组织细胞的基础代谢率，减少细胞的能量消耗。与传统临床保存方法相比，不仅保存温度降低4-5℃，保存时间也从理论上16小时延长到实际可行的36小时，成为未来极具应用前景的低温保存方法。本论文为国家自然科学基金资助项目（课题编号:No.51076117）
[Abstract]:Ice temperature preservation technology is a new technology to save, the extension of complex biological preservation time as the background, the use of biological methods, thermal physics, clinical medicine and other multidisciplinary combination of biological tissue, heat and mass transfer during ice temperature preservation process was studied. The research contents are the basic composition of organisms unit cell cryopreservation and whole organ of ice temperature preservation and transplantation, compared with the current clinical preservation method, at the micro level and macro level of ice temperature preservation delaying technology applied to complex biological tissue heat and mass transfer mechanism.
In this paper, the renal epidermal cells as the research object, using the method of analysis of the microscope images, at different temperature, permeability under different osmotic pressure, including non permeable cell volume, cell membrane of water and cryoprotectant permeability coefficient. The results showed that in isotonic solution, the average cell etc. infiltration volume Viso=2472.58 M3; non penetration volume Vb=0.22Viso; observe cell in higher temperature protection penetrant solution in response to the two parameter model used at different temperatures are obtained in two dimethyl sulfoxide, ethylene glycol, the coefficient of permeability of renal epidermal cells in glycerin solution to water (Lp), permeability of the cryoprotective agent the (Ps) and activation energy (Ea); the survival rate by comparing the cells in ice temperature storage, obtained for renal epidermal cells the best storage temperature.
In the bio heat transfer model, porous media model can describe the characteristics of kidney tissue, porous skeleton composed of cells, and for blood and other body fluids circulation by capillary and lymphatic formation. In the process of porous media model, it is necessary to carry out the determination of physical properties of kidney. The two most basic the characteristic parameters of the kidney, the porosity and permeability were studied. The results show that the porosity of pig kidney is phi =15.64%, provides the experimental basis for K=14.5 m2. permeability of the results for the numerical simulation of the kidney cold perfusion process.
The first part from the cold perfusion process body kidney as ice temperature preservation, has important clinical value for studying the change of the temperature field in the process of kidney, kidney on renal cold perfusion process, surface temperature and internal temperature of comprehensive monitoring. On the basis of the experiment, 3D reconstruction of the renal artery and vein and the appearance of kidney using vascular casting, physical model of the kidney, and import the Fluent fluid dynamics simulation software, combined with pipe laminar flow model in porous media and kidney tissue model, to reconstruct the 3D temperature field of kidney cold perfusion process. The simulation results are compared with the experimental results, to explore the cold stimulation. The temperature change caused by the kidney, perfusion, and the simulation result of the temperature field was studied.
Finally, based on the above research, the clinical trials of autologous transplantation of pig kidney, will be at -0.8 deg.c for 36 hours after the ice temperature preservation, re implantation, fourth days after transplantation, normal physiological indexes. The experiment verifies the basic metabolism of ice temperature preservation method can suppress cell rate, reduce cellular energy consumption. Compared with the traditional clinical method of preservation, not only save reduces the temperature of 4-5 DEG C, extend the preservation time is theoretically feasible 16 hours to 36 hours, become the future promising cryopreservation method.
This paper is a project funded by the National Natural Science Foundation (project number: No.51076117)

【学位授予单位】：天津商业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB69;R692

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