An ultrastructural 3D reconstruction method for observing the arrangement of collagen fibrils and proteoglycans in the human aortic wall under mechanical load

• DOI: 10.1016/j.actbio.2022.01.036
• Publication Date: 2022-01-19T23:35:02Z
• Authors: Anna Pukaluk; Anna-Sophie Wittg...; Gerd Leitinger; Dagmar Kolb; Dominique Pernitsch; Sarah A. Schneider; Patrick Knöbelreiter; Verena Horak; Kristian Bredies; Gerhard A. Holzapfel; Thomas Pock; Gerhard Sommer
• Keywords: Collagen fibril

An insight into changes of soft biological tissue ultrastructures under loading conditions is essential to understand their response mechanical stimuli. Therefore, this study offers an approach investigate the arrangement collagen fibrils and proteoglycans (PGs), which are located within mechanically loaded aortic wall. The human samples were either fixed directly with glutaraldehyde in load-free state or subjected a planar biaxial extension test prior fixation. ultrastructure was recorded using electron tomography. Collagen PGs segmented convolutional neural networks, particularly ESPNet model. 3D ultrastructural reconstructions revealed complex organization PGs. In particular, we observed that not all attached fibrils, but some fill spaces between clear distance collagen. cannot be fully captured can severely misinterpreted 2D. developed opens up practical possibilities, including quantification spatial relationship as function load. Such also used compare tissues different conditions, e.g., healthy diseased, improve develop new material models. enables reconstruction they embedded This methodological pipeline comprises knowledge arterial mechanics, imaging transmission microscopy tomography, segmentation image data sets networks finally unique caused by