Extracellular Matrix-Contractile Response Coupling of the Aortic Heart Valve Interstitial Cell

The role of aortic valve interstitial cell (AVIC) and extracellular matrix (ECM) interactions of the aortic valve (AV) are not well understood. Distinct differences in the composition and structure of the AV leaflet layers (fibrosa and ventricularis) have been shown to influence mechanical properties ¹. Our ability to measure the effects of changes in cellular stiffness in the dense collagenous AV leaflets (AVL) ² offers a unique opportunity to explore the in-situ AVIC stiffness and local AVIC-ECM mechanical interactions. In the present study, a multi-scale finite element model approach was developed based on our simulations of our flexural stiffness experiment ² were used to develop effective layer dependent mechanical properties. In addition, we present a predictive model for the alteration of AVL tissue mechanical properties resulting from AVIC contraction. This model provides a means to probe the layer dependent properties under the influence of AVIC contraction relative to an intact tissue state. By establishing a procedure to examine ECM stiffness in situ, through coupled experimental and computational methods, insights into relative contributions of ECM components were developed. Finally, in contrast previous study, where tissue stiffness was reported in terms on an instantaneous elastic modules, this work provides a more complete mechanical response of AVL in flexure.