Department of Mechanical Engineering, Temple University.
Department of Bioengineering, Temple University.
J Vis Exp. 2021 Dec 9(178). doi: 10.3791/63312.
Leukocyte-endothelial cell interactions play an important role in inflammatory diseases such as sepsis. During inflammation, excessive migration of activated leukocytes across the vascular endothelium into key organs can lead to organ failure. A physiologically relevant biomimetic microfluidic assay (bMFA) has been developed and validated using several experimental and computational techniques, which can reproduce the entire leukocyte rolling/adhesion/migration cascade to study leukocyte-endothelial cell interactions. Microvascular networks obtained from in vivo images in rodents were digitized using a Geographic Information System (GIS) approach and microfabricated with polydimethylsiloxane (PDMS) on a microscope slide. To study the effect of shear rate and vascular topology on leukocyte-endothelial cell interactions, a Computational Fluid Dynamics (CFD) model was developed to generate a corresponding map of shear rates and velocities throughout the network. The bMFA enables the quantification of leukocyte-endothelial cells interactions, including rolling velocity, number of adhered leukocytes in response to different shear rates, number of migrated leukocytes, endothelial cell permeability, adhesion molecule expression and other important variables. Furthermore, by using human-related samples, such as human endothelial cells and leukocytes, bMFA provides a tool for rapid screening of potential therapeutics to increase their clinical translatability.
白细胞-内皮细胞相互作用在炎症性疾病（如败血症）中起着重要作用。在炎症过程中，激活的白细胞过度迁移穿过血管内皮进入关键器官会导致器官衰竭。已经开发并使用几种实验和计算技术验证了一种生理相关的仿生微流控测定法（bMFA），该方法可以复制整个白细胞滚动/粘附/迁移级联，以研究白细胞-内皮细胞相互作用。使用地理信息系统（GIS）方法对来自啮齿动物体内图像的微血管网络进行数字化处理，并在显微镜载玻片上用聚二甲基硅氧烷（PDMS）进行微加工。为了研究剪切率和血管拓扑结构对白细胞-内皮细胞相互作用的影响，开发了计算流体动力学（CFD）模型，以生成整个网络中剪切率和速度的相应图谱。bMFA 能够定量测量白细胞-内皮细胞相互作用，包括滚动速度、对不同剪切率的粘附白细胞数量、迁移白细胞数量、内皮细胞通透性、粘附分子表达和其他重要变量。此外，通过使用与人相关的样本，如人内皮细胞和白细胞，bMFA 提供了一种快速筛选潜在治疗方法的工具，以提高其临床转化能力。
