Analysis of Fiber Network Architecture in Blood Vessels and Blood Clots

Fibrous networks, including collagen and fibrin, provide strength and support, and are critical for maintaining homeostasis. In this study, we have developed algorithms to define the structural properties of collagen and fibrin networks from microscopic images of these networks in abdominal aortic aneurysms (AAA) and blood clots, respectively. AAA is a biomechanical disease characterized by significant changes in the structure and strength of the arterial wall due to differential changes in the composition of fibrillar collagen in adventitial and medial layers. Using bright-field and polarized microscopic images of histological sections of mouse aorta stained with Picrosirius red (PSR) stain, we developed MATLAB code to locally quantify collagen content within the vessel wall. The method was benchmarked against manual quantification, and the superiority of the automated analysis was established by statistical analyses of accuracy and reproducibility. Fibrin networks form the structural and functional basis of blood clots. We developed an algorithm using a combination of ImageJ plugins and a custom MATLAB code to analyze the ultrastructure of blood clots from the scanning electron microscopic images of fibrin networks. This morphometric profile was used to correlate clot structure to mechanics, which has implications for our understanding of hemostasis and thrombosis