Journal of Synchrotron Radiation

Volume 12, Part 6 (November 2005)

research papers

J. Synchrotron Rad. (2005). 12, 727-733 [ doi:10.1107/S0909049505012549 ]

In situ tensile testing of human aortas by time-resolved small-angle X-ray scattering

F. Schmid, G. Sommer, M. Rappolt, C. A. J. Schulze-Bauer, P. Regitnig, G. A. Holzapfel, P. Laggner and H. Amenitsch

Abstract: The collagen diffraction patterns of human aortas under uniaxial tensile test conditions have been investigated by synchrotron small-angle X-ray scattering. Using a recently designed tensile testing device the orientation and d-spacing of the collagen fibers in the adventitial layer have been measured in situ with the macroscopic force and sample stretching under physiological conditions. The results show a direct relation between the orientation and extension of the collagen fibers on the nanoscopic level and the macroscopic stress and strain. This is attributed first to a straightening, second to a reorientation of the collagen fibers, and third to an uptake of the increasing loads by the collagen fibers.

Keywords: human tissue; biomechanics; artery; small-angle X-ray scattering; collagen; fiber diffraction; tensile testing.