外磁场作用下磁性载药颗粒的聚集性研究

发布时间：2018-03-21 11:09

本文选题：药物靶向递送　切入点：磁性载药微粒　出处：《重庆大学》2014年硕士论文　论文类型：学位论文

【摘要】：传统的药物传递系统通常采取静脉注射的方式将药物运送到血管中，然后通过血液自身的流动将注射的药物带动到全身以及病变的区域，由于药物分散到全身，在病变区域的相对浓度较低，所能达到的治疗效果相对较低，可能导致治疗周期性延长，治愈效果减弱。如欲获得更理想的治疗效果，就必须加大药物剂量，这样就能在目标区域得到治疗的理想浓度，但是药物对正常细胞会产生负面效果，对人体带来一定程度的损伤。为了克服传统医学上的这些问题，人们提出了许多药物靶向递送的方法，但是这些方法都还处于理论和模拟阶段，应用到临床中尚需时日。其中的一种方法，即将治疗药物包裹到磁性纳米颗粒上，然后通过外部条件的控制有效地实现颗粒在体内有目的的传送、聚集和对已经病变的区域实现靶向性的治疗。实用上，可将治疗药物裹覆在集群磁性颗粒的表面，通过外部放置磁场的定向引导,最终将药物递送到体内发生病变的区域目的性的释放。如此不仅降低了传统递送的缺点以及毒副作用,而且更直接地增加了局部区域的药物浓度,有利于提高治疗，降低药物对正常细胞的副作用。这些药物靶向输运的优越性无疑对包括癌症在内的疾病的治疗具有巨大的应用前景和市场需求。本文介绍了在血液的粘性和外磁场作用下载药物微粒在血管中的流动、聚集等力学特性，建立了一个数学模型。进而忽略颗粒的重力、浮力等影响以及颗粒之间的相互作用，重点分析了粘性阻力和磁场力对颗粒流动的作用，提出了载体颗粒的流动模型。模型从理论上描述了磁性载体颗粒在血管中流动时磁矩对颗粒轨迹的影响以及微粒半径对颗粒捕捉效率以及与磁场强度的关系。借助Matlab数值分析了磁性载体微粒的运动过程;用计算流体力学方法和Fluent软件模拟了磁矩、颗粒半径等对磁颗粒捕获的作用;仿真结果与数值结果基本一致,得到了三维空间中不同条件的捕获效率。由于外部磁场条件的导向，，取得了治疗药物目的性聚集的效果。数学模型模拟结果和仿真结果有相似的颗粒聚集特征。因此，本文中提出的数学模型在一定条件下描述了载药颗粒的流动、聚集与外部磁场强度的关系。利用所提出的流体动模型分析了磁性载体的流动与颗粒半径和磁矩的关系，可为磁性药物靶向递送的应用提供参考。
[Abstract]:The traditional drug delivery system usually carries drugs into the blood vessels by intravenous injection, and then drives the injected drugs to the whole body and the diseased areas through the flow of the blood itself, because the drugs are dispersed throughout the body. The relative concentration in the diseased area is relatively low and the therapeutic effect is relatively low, which may lead to the prolongation of the treatment cycle and the weakening of the cure effect. If you want to obtain a better therapeutic effect, you must increase the dosage of the drug. In this way, the ideal concentration of treatment can be obtained in the target area, but the drug will have a negative effect on normal cells and cause a certain degree of damage to the human body. In order to overcome these problems in traditional medicine, Many methods of targeted delivery of drugs have been proposed, but these methods are still in the theoretical and simulation stages and will take some time to be applied to clinical applications. One of them is that therapeutic drugs are encapsulated on magnetic nanoparticles. Then through the control of external conditions, the particles can be effectively transported, aggregated and targeted treatment of the diseased areas in vivo. In practice, the therapeutic drugs can be coated on the surface of the cluster magnetic particles. Through the directional guidance of the external magnetic field, the drug is eventually delivered to the disease-causing region of the body for purposeful release, which not only reduces the disadvantages of traditional delivery, but also reduces the side effects. And more directly increases the concentration of drugs in local areas, which is helpful to improve the treatment. The advantages of targeted delivery of these drugs undoubtedly have great application prospects and market demand for the treatment of diseases including cancer. In this paper, the flow and aggregation of drug particles in blood vessels are introduced, and a mathematical model is established. The effects of gravity and buoyancy of particles and the interaction between particles are ignored. The effects of viscous resistance and magnetic field force on particle flow are emphatically analyzed. A flow model of carrier particles is proposed, which theoretically describes the effect of magnetic moment on particle trajectory and the relationship between particle radius and particle capture efficiency and magnetic field intensity. The moving process of magnetic carrier particles is analyzed numerically by Matlab. The effect of magnetic moment and particle radius on magnetic particle capture is simulated by using computational fluid dynamics method and Fluent software. The simulation results are in good agreement with the numerical results, and the capture efficiency of different conditions in three-dimensional space is obtained. Due to the guidance of external magnetic field conditions, the therapeutic effect of targeted drug aggregation is achieved. The simulation results of the mathematical model and the simulation results have similar particle aggregation characteristics. The mathematical model proposed in this paper describes the relationship between the flow, aggregation and external magnetic field intensity of the drug-loaded particles under certain conditions. The relationship between the flow of the magnetic carrier and the particle radius and magnetic moment is analyzed by using the proposed fluid dynamic model. It can provide reference for the application of magnetic drug targeted delivery.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R943

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