Quantifying age-related changes in the structure and mechanical function of skin with multiscale imaging

Second-harmonic generation microscopy and macro-scale imaging were combined to enable multiscale assessments of mouse skin undergoing uniaxial mechanical testing. Skin from old and young mice experienced a substantial micro-scale volume reduction during uniaxial tension. A non-affine relationship between the 3D collagen fiber kinematics and local deformation was also observed. Aged skin was found to have a lower stiffness but increased collagen fiber realignment during mechanical loading. These results are being used to develop multiscale models of skin mechanics and obtain a more complete understanding of age-related changes in skin structure-function relationships.