| Abstract Scope |
Abdominal aortic aneurysms (AAA) involve significant remodeling of the vessel wall, affecting both intracellular structures and the extracellular matrix (ECM). While decreased collagen fiber waviness has been noted in AAA, collagen fibril-level changes remain poorly understood. To address this, collagen fibrils were isolated from human AAA tissues collected during surgery and compared to healthy aortic controls. Transmission electron microscopy and atomic force microscopy revealed key differences in morphology and mechanics. AAA fibrils showed disrupted D-periodicity, irregular morphology, and altered mechanical properties, including changes in stiffness, storage modulus, and loss modulus. Viscoelastic measurements at both ECM and fibril levels confirmed notable differences between aneurysmal and healthy tissues. These nanoscale abnormalities resemble those seen with chronic inflammation or mechanical stress, suggesting that collagen fibril-level damage may contribute to ECM dysfunction in AAA. Understanding these fibrillar alterations could improve insight into the pathophysiology of AAA and other vascular diseases involving ECM degradation. |