Department of Biomedical Engineering, CaseWestern Reserve University, Cleveland, OH 44106, USA.
Nanotechnology. 2011 Mar 18;22(11):115101. doi: 10.1088/0957-4484/22/11/115101.
In the recent past, remarkable advances in nanotechnology have generated nanoparticles of different shapes and sizes, which have been shown to exhibit unique properties suitable for biomedical applications such as cancer therapy and imaging. Obviously, all nanoparticles are not made equal. This becomes evident when we consider their transport behavior under blood flow in microcirculation. In this work, we evaluated the effect of critical physical characteristics such as the particle shape, size and density on a nanoparticle's tendency to marginate towards the vessel walls in microcirculation using an in vitro model. The wall deposition of nanoparticles was tested in a fibronectin-coated microfluidic channel at a physiologically relevant flow rate. Different classes of nanoparticles (liposome, metal particles) of different sizes (60-130 nm), densities (1-19 g ml(-1)) and shapes (sphere, rod) displayed significantly different deposition as a result of different margination rates. The smaller-sized and the oblate-shaped particles displayed a favorable behavior as indicated by their higher margination rates. Notably, the particle density showed an even more essential role, as it was observed that the lighter particles marginated significantly more. Since nanoparticles must escape the flow in order to approach the vascular bed and subsequently extravascular components for meaningful interactions, the design of nanoparticles strongly affects their margination, a key factor for their ultimate in vivo effectiveness.
在最近的过去，纳米技术的显著进步产生了不同形状和大小的纳米粒子，这些纳米粒子表现出独特的性质，适合于癌症治疗和成像等生物医学应用。显然，并非所有的纳米粒子都是一样的。当我们考虑它们在微循环中的血流下的传输行为时，这一点变得显而易见。在这项工作中，我们使用体外模型评估了关键物理特性（如颗粒形状、尺寸和密度）对纳米颗粒在微循环中向血管壁边缘迁移倾向的影响。在生理相关流速下，在纤维连接蛋白涂覆的微流控通道中测试了纳米颗粒的壁沉积。不同大小（60-130nm）、密度（1-19g/ml）和形状（球体、棒体）的不同类别的纳米颗粒（脂质体、金属颗粒）表现出明显不同的沉积，这是由于不同的边缘迁移率造成的。较小尺寸和扁球体形状的颗粒表现出有利的行为，这表明它们具有更高的边缘迁移率。值得注意的是，颗粒密度起着更为重要的作用，因为观察到较轻的颗粒边缘迁移显著更多。由于纳米颗粒必须逃脱流动才能接近血管床和随后的血管外成分进行有意义的相互作用，纳米颗粒的设计强烈影响它们的边缘迁移，这是它们最终在体内有效性的关键因素。
