Age-dependent arterial mechanics via a multi scale elastic approach

A multiscale mechanical model for arterial walls is proposed to describe their age-dependent elastic behavior. The model accounts for nanoscale mechanisms related to molecular and cross-link stretching, as well as for micro- and macroscale effects, by employing homogenization techniques. Such a model uses only a few measurable histological parameters, and allows the reproduction of well-established experimental evidence, highlighting that stiffness of collagen fibrils is related to both cross-link density and their mechanical properties. In the case of aortic walls, the model allows to account for histological alterations occurring with age, fully reproducing available experimental results. Proposed evidence also gives a clear mechanical interpretation of the influence of cross-link density and stiffness on arterial tissue elastic modulus and arterial compliance.