Endothelial cell distributions and migration under conditions of flow shear stress around a stent wire

Background: Blood vessels are constantly exposed to flow-induced stresses, and endothelial cells (ECs) respond to these stresses in various ways.

Objective: In order to facilitate endothelialization after endovascular implantation, cell behaviors around a metallic wire using a flow circulation system are observed.

Methods: A parallel flow chamber was designed to reproduce constant shear stresses (SSs) on cell surfaces and to examine the effects of a straight bare metal wire on cell monolayers. Cells were then exposed to flow for 24 h under SS conditions of 1, 2, and 3 Pa. Subsequently, cell distributions were observed on the plate of the flow chamber and on the surface of the bare metal wire. Flow fields inside the flow chamber were analyzed using computational fluid dynamics under each SS condition.

Results: After 24 h, ECs on the bottom plate were concentrated toward the area of flow reattachment. The matching of higher cell density and CFD result suggests that flow-induced stimuli have an influence on EC distributions.

Conclusion: Typical cell concentration occurs on dish plate along the vortexes, which produces large changes in SSs on cell layer.