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Localized endothelial‐based control of platelet aggregation and coagulation under flow: A proof‐of‐principle vessel‐on‐a‐chip study
Author(s) -
Brouns Sanne L.N.,
Provenzale Isabella,
Geffen Johanna P.,
Meijden Paola E.J.,
Heemskerk Johan W.M.
Publication year - 2020
Publication title -
journal of thrombosis and haemostasis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.947
H-Index - 178
eISSN - 1538-7836
pISSN - 1538-7933
DOI - 10.1111/jth.14719
Subject(s) - coagulation , proof of concept , platelet aggregation , platelet , chemistry , computer science , medicine , operating system
Background In the intact vessel wall, endothelial cells form a barrier between the blood and the remaining vascular structures, serving to maintain blood fluidity and preventing platelet activation and fibrin clot formation. The spatiotemporal space of this inhibition is largely unknown. Objective To assess the local inhibitory roles of a discontinuous endothelium, we developed a vessel‐on‐a‐chip model, consisting of a microfluidic chamber coated with the thrombogenic collagen and tissue factor (TF), and covered with patches of human endothelial cells. By flow perfusion of human blood and plasma, the heterogeneous formation of platelet aggregates and fibrin clots was monitored by multicolor fluorescence microscopy. Results On collagen/TF coatings, a coverage of 40% to 60% of human umbilical vein endothelial cells resulted in a strong overall delay in platelet deposition and fibrin fiber formation under flow. Fibrin formation colocalized with the deposited platelets, and was restricted to regions in between endothelial cells, thus pointing to immediate local suppression of the clotting process. Fibrin kinetics were enhanced by treatment of the cells with heparinase III, partially disrupting the glycocalyx, and to a lesser degree by antagonism of the endothelial thrombomodulin. Co‐coating of purified thrombomodulin and collagen had a similar coagulation‐suppressing effect as endothelial thrombomodulin. Conclusions In this vessel‐on‐a‐chip system with patches of endothelial cells on thrombogenic surfaces, the coagulant activity under flow is regulated by: (a) the residual exposure of trigger (collagen/TF), (b) the endothelial glycocalyx, and (c) to a lesser degree the endothelial thrombomodulin.