Shaping nano-/micro-particles for enhanced vascular interaction in laminar flows
Shaping nano-/micro-particles for enhanced vascular interaction in laminar flows
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DOI：
10.1088/0957-4484/20/49/495101
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发表时间：
2009-12-09
期刊：
影响因子：
3.5
通讯作者：
Decuzzi, Paolo
中科院分区：
文献类型：
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作者：
Lee, Sei-Young;Ferrari, Mauro;Decuzzi, Paolo
非球形纳米/微米颗粒可以在流体动力学和惯性力的共同作用下在线性层流中横向漂移（流体动力学边缘化）。这样的特征可以在基于颗粒的血管内和肺部递送系统的合理设计中被利用，并且用于设计用于高通量颗粒分离的新的流动分级系统。提出了一种预测非球形颗粒边集行为的通用方法。横向漂移速度取决于粒子的Stokes数St（a），并随着粒子的尺寸、密度和转动惯量而增长。细长颗粒，特别是低纵横比的盘状颗粒，在线性层流中表现出最大的边缘化倾向。（S < 100 s（-1）），非球形颗粒围绕其轨迹振荡，并且边缘化只能通过施加外力场来实现（重力，磁性）;而对于较大的S（100 s（-1）< S < 10（4）s（-1）），微米颗粒可以达到1-10 μ m s（-1）的漂移速度。在肺循环中，即使对于亚微米颗粒也可以观察到流体动力学边集。最后，非球形颗粒横向漂移的固有倾向可以有效地用于设计微流体装置，基于流动分级方法，用于颗粒分离而不使用外部横向力场。
Non-spherical nano-/micro-particles can drift laterally (hydrodynamic margination) in a linear laminar flow under the concurrent effect of hydrodynamic and inertial forces. Such a feature can be exploited in the rational design of particle-based intravascular and pulmonary delivery systems and for designing new flow fractioning systems for high-throughput particle separation. A general approach is presented to predict the marginating behavior of non-spherical particles. The lateral drift velocity is shown to depend on the particle Stokes number St(a) and to grow with the size, density and rotational inertia of the particle. Elongated particles, in particular, low aspect ratio discoidal particles, exhibit the largest propensity to marginate in a linear laminar flow.In the blood microcirculation, at low shear rates (S < 100 s(-1)), non-spherical particles oscillate around their trajectory and margination can only be achieved through the application of external force fields (gravitational, magnetic); whereas for larger S (100 s(-1) < S < 10(4) s(-1)), micrometer particles can achieve drift velocities in the order of 1-10 mu m s(-1). In the pulmonary circulation, hydrodynamic margination can be observed even for sub-micrometer particles. Finally, the inherent propensity of non-spherical particles to drift laterally can be effectively exploited for designing microfluidic devices, based on the flow fractioning approach, for particle separation without using external lateral force fields.