Ryan W Muthard1, Scott L Diamond. 1. Department of Chemical and Biomolecular Engineering, Vagelos Research Laboratory, Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
Abstract
OBJECTIVE: Blood clots form under flow during intravascular thrombosis or vessel leakage. Prevailing hemodynamics influence thrombus structure and may regulate contraction processes. A microfluidic device capable of flowing human blood over a side channel plugged with collagen (± tissue factor) was used to measure thrombus permeability (κ) and contraction at controlled transthrombus pressure drops. METHODS AND RESULTS: The collagen (κ(collagen)=1.98 × 10(-11) cm(2)) supported formation of a 20-µm thick platelet layer, which unexpectedly underwent massive platelet retraction on flow arrest. This contraction resulted in a 5.34-fold increase in permeability because of collagen restructuring. Without stopping flow, platelet deposits (no fibrin) had a permeability of κ(platelet)=5.45 × 10(-14) cm(2) and platelet-fibrin thrombi had κ(thrombus)=2.71 × 10(-14) cm(2) for ΔP=20.7 to 23.4 mm Hg, the first ever measurements for clots formed under arterial flow (1130 s(-1) wall shear rate). Platelet sensing of flow cessation triggered a 4.6- to 6.5-fold (n=3, P<0.05) increase in contraction rate, which was also observed in a rigid, impermeable parallel-plate microfluidic device. This triggered contraction was blocked by the myosin IIA inhibitor blebbistatin and by inhibitors of thromboxane A2 (TXA(2)) and ADP signaling. In addition, flow arrest triggered platelet intracellular calcium mobilization, which was blocked by TXA(2)/ADP inhibitors. As clots become occlusive or blood pools following vessel leakage, the flow diminishes, consequently allowing full platelet retraction. CONCLUSIONS: Flow dilution of ADP and thromboxane regulates platelet contractility with prevailing hemodynamics, a newly defined flow-sensing mechanism to regulate clot function.
OBJECTIVE: Blood clots form under flow during intravascular thrombosis or vessel leakage. Prevailing hemodynamics influence thrombus structure and may regulate contraction processes. A microfluidic device capable of flowing human blood over a side channel plugged with collagen (± tissue factor) was used to measure thrombus permeability (κ) and contraction at controlled transthrombus pressure drops. METHODS AND RESULTS: The collagen (κ(collagen)=1.98 × 10(-11) cm(2)) supported formation of a 20-µm thick platelet layer, which unexpectedly underwent massive platelet retraction on flow arrest. This contraction resulted in a 5.34-fold increase in permeability because of collagen restructuring. Without stopping flow, platelet deposits (no fibrin) had a permeability of κ(platelet)=5.45 × 10(-14) cm(2) and platelet-fibrin thrombi had κ(thrombus)=2.71 × 10(-14) cm(2) for ΔP=20.7 to 23.4 mm Hg, the first ever measurements for clots formed under arterial flow (1130 s(-1) wall shear rate). Platelet sensing of flow cessation triggered a 4.6- to 6.5-fold (n=3, P<0.05) increase in contraction rate, which was also observed in a rigid, impermeable parallel-plate microfluidic device. This triggered contraction was blocked by the myosin IIA inhibitor blebbistatin and by inhibitors of thromboxane A2 (TXA(2)) and ADP signaling. In addition, flow arrest triggered platelet intracellular calcium mobilization, which was blocked by TXA(2)/ADP inhibitors. As clots become occlusive or blood pools following vessel leakage, the flow diminishes, consequently allowing full platelet retraction. CONCLUSIONS: Flow dilution of ADP and thromboxane regulates platelet contractility with prevailing hemodynamics, a newly defined flow-sensing mechanism to regulate clot function.
Authors: Wilbur A Lam; Ovijit Chaudhuri; Ailey Crow; Kevin D Webster; Tai-De Li; Ashley Kita; James Huang; Daniel A Fletcher Journal: Nat Mater Date: 2010-12-05 Impact factor: 43.841
Authors: John D Welsh; Ryan W Muthard; Timothy J Stalker; Joshua P Taliaferro; Scott L Diamond; Lawrence F Brass Journal: Blood Date: 2016-01-06 Impact factor: 22.113
Authors: Maurizio Tomaiuolo; Timothy J Stalker; John D Welsh; Scott L Diamond; Talid Sinno; Lawrence F Brass Journal: Blood Date: 2014-06-20 Impact factor: 22.113
Authors: John D Welsh; Timothy J Stalker; Roman Voronov; Ryan W Muthard; Maurizio Tomaiuolo; Scott L Diamond; Lawrence F Brass Journal: Blood Date: 2014-06-20 Impact factor: 22.113
Authors: Shixin Xu; Zhiliang Xu; Oleg V Kim; Rustem I Litvinov; John W Weisel; Mark Alber Journal: J R Soc Interface Date: 2017-11 Impact factor: 4.118
Authors: Peter Höök; Teresa Brito-Robinson; Oleg Kim; Cody Narciso; Holly V Goodson; John W Weisel; Mark S Alber; Jeremiah J Zartman Journal: Biomed Opt Express Date: 2017-07-17 Impact factor: 3.732
Authors: H B Moore; E E Moore; M P Chapman; E Gonzalez; A L Slaughter; A P Morton; A D'Alessandro; K C Hansen; A Sauaia; A Banerjee; C C Silliman Journal: J Thromb Haemost Date: 2015-09-22 Impact factor: 5.824