Fig. 2
From: A microengineered vascularized bleeding model that integrates the principal components of hemostasis
Integrin αIIbβ3 antagonism alters hemostatic plug architecture by inhibiting platelet–fibrin binding and clot contraction. a Healthy blood treated with 10 µg ml−1 eptifibatide, an anti-platelet drug commonly used in the clinical setting, and healthy blood with vehicle control exhibit similar in vitro bleeding times. b Moreover, the total areas of adhered platelets are also similar between the two conditions. c However, when comparing platelet aggregation followed by clot contraction, which is tracked by measuring the areas of saturated intensity of fluorescently labeled platelets over time, eptifibatide-treated blood exhibited significantly less platelet aggregation and clot contraction over the time course of hemostasis as compared to vehicle control conditions. The error bars in the graphs show standard errors (control n = 3, eptifibatide n = 4). Double asterisk (**) shows P-value < 0.05 by Student's t-test. d Heat map of adhered platelets shows dense platelet aggregates with saturated fluorescence intensity formed in vehicle control conditions at 20 min after bleeding (top) while no aggregation or clot contraction observed in eptifibatide-treated blood (bottom). e Under the eptifibatide-treated conditions, platelet–fibrin binding (as defined by co-localization of platelets—red—and fibrinogen/fibrin—green) was markedly decreased compared to that of the control conditions. f, g The analyzed images of a representative experiment with healthy control and eptifibatide-treated blood samples (left) and the corresponding platelet-fibrin(ogen) co-localization plot (right). Each co-localization plot displays the pixel intensity of the red channel (x axis), corresponding to platelets, plotted against the pixel intensity of the green channel (y axis), corresponding to fibrin(ogen), of each pixel in the respective image. The red lines show the Pearson correlation coefficient lines. h Comparing Pearson correlation coefficients between healthy control and eptifibatide-treated samples (n = 5 for each condition) reveals that co-localization is more pronounced in the control condition (Student's t-test, P = 0.008). All scale bars = 50 µm. Bars in graph represent median values
