磁性靶向药物递送中铁磁流体的动力学建模

在所有人体内进行的药物递送技术中，磁性药物靶向递送治疗由于其非入侵性和高靶向性而成为主要的方法．磁性药物靶向递送是将药物装载到磁性纳米颗粒上，利用外部磁场使其移动并聚焦在靶部位的方法．该法能提高靶部位药物的浓度，降低药物对正常组织的毒副作用．尽管已经有不少磁性靶向药物递送的理论分析，但是很少有人研究磁流体在血管里的流体动力学模型．该文提出了一个数学模型来描述作为药物载体的铁磁流体在外磁场作用下,在血管里的流体动力学特性，并在模型中增加了磁场力以及由此产生的不对称应力，增加了磁性纳米颗粒在磁场作用下的角动量方程．由于运动方程的数学复杂性，通过保留数学模型里物理特性最显著项来获得工程近似．用计算流体力学（CFD）进行数值仿真，分析了铁磁流体在一个模拟动脉瘤血管的三维管道里的流动状况，来进一步理解铁磁流体的临床应用．仿真结果和动物实验相一致．分析结果对于磁性靶向药物递送的各种应用提供了可参考的数据．

Hydrodynamic Modeling of Ferrofluids Flow in Magnetic Targeting Drug Delivery

Among the proposed techniques for delivering drugs to specific locations within the human body,magnetic drug targeting surpasses due to its non-invasive character and its high targeting efficiency.Magnetic targeting drug delivery is a method of carrying drug-loaded magnetic nanoparticles to a tissue target under the applied magnetic field.This method increases the drug concentration in target and reduces the adverse side-effects.Although there have been some analyses theoretically for magnetic drug targeting,very few researchers have addressed the hydrodynamic models of magnetic fluids in the blood vessel of human body.A mathematical model was presented to describe the hydrodynamics of ferrofluids as drug carriers flowing in a blood vessel under the applied magnetic field.In this model,the magnetic force and the asymmetrical force were added and an angular momentum equation of magnetic nanoparticles under the applied magnetic field was modeled.And engineering approximations were achieved by retaining the physically most significant items in the mathematical model due to the mathematical complexity of the motion equations.Numerical simulations were performed to obtain better insight into the theoretical model with computational fluid dynamics(CFD)'simulation results demonstrate the important parameters leading to adequate drug delivery to the target site depending on the magnetic field intensity,which coincide with those animal experiments.Results of the analysis provide important information and can suggest strategies for improving delivery in favor of the clinic application.