Biomechanical and Microstructural Properties of Fibulin-5 Null Mice

Fibulin-5 is an extracellular matrix (ECM) protein that interacts with integrins and plays a critical role in organizing elastic fibers. Gross observation and histological examination reveal that carotid arteries from fibulin-5 knockout (fib5-/-) mice have disrupted elastic lamellae and are more tortuous [1]. The properties of fibulin-5 null mice provide a unique platform for developing constituent based models for vascular mechanics. While numerous models for blood vessels exist, there is a need to relate measurable microstructural metrics of structurally-based constitutive relations. We performed mechanical tests on carotid arteries from wildtype (WT) and fib5-/-mice and imaged live vessels under multiple loading scenarios to quantify microstructure during deformation. We also fit experimental results to a constitutive relation based on Holzapfel’s model [2]. These results provide a basis for further model development.