Endothelial cells (ECs) play a major role in the healing process following angioplasty to inhibit excessive neointima. This makes the process of EC healing after injury, in particular EC migration in a stented vessel, important for recovery of normal vessel function. In that context, we present a novel particle-based model of EC migration and validate it against in vitro experimental data. We have developed a particle-based model of EC migration under flow conditions in an in vitro vessel with obstacles. Cell movement in the model is a combination of random walks and directed movement along the local flow velocity vector. For model calibration, a set of experimental data for cell migration in a similarly shaped channel has been used. We have calibrated the model for a baseline case of a channel with no obstacles and then applied it to the case of a channel with ridges on the bottom surface, representative of stent strut geometry. We were able to closely reproduce the cell migration speed and angular distribution of their movement relative to the flow direction reported in vitro. The model also reproduces qualitative aspects of EC migration, such as entrapment of cells downstream from the flow-disturbing ridge. The model has the potential, after more extensive in vitro validation, to study the effect of variation in strut spacing and shape, through modification of the local flow, on EC migration. The results of this study support the hypothesis that EC migration is strongly affected by the direction and magnitude of local wall shear stress.

中文翻译：

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在流动条件下内皮细胞迁移的基于粒子的模型。

内皮细胞（EC）在血管成形术后的愈合过程中起主要作用，以抑制过多的新内膜。这使得受伤后的EC愈合过程，特别是EC在带支架血管中的迁移对于恢复正常血管功能很重要。在这种情况下，我们提出了一种新型的基于粒子的EC迁移模型，并针对体外实验数据进行了验证。我们已经开发了基于粒子的EC模型，该模型在有障碍物的体外血管中流动条件下进行。模型中的单元运动是随机游走和沿局部流速矢量的定向运动的组合。对于模型校准，已使用了一组用于在形状相似的通道中进行细胞迁移的实验数据。我们已经针对没有障碍物的通道的基准情况对模型进行了校准，然后将其应用于底面上有脊的通道情况（代表支架支杆的几何形状）。我们能够精确地再现细胞迁移速度及其相对于体外报道的流向的运动角度分布。该模型还再现了EC迁移的定性方面，例如在扰流脊下游截留了细胞。经过更广泛的体外验证后，该模型有潜力研究支杆间距和形状的变化（通过修改局部流量）对EC迁移的影响。这项研究的结果支持以下假设：EC迁移受到局​​部壁剪应力的方向和大小的强烈影响。