3D characterization of nanoscale deformation mechanisms in the Achilles tendon enthesis using Texture tomography

The enthesis is an insertion site of tendon into bone featuring a complex organization. Gradients in composition, structure and structure yield exceptional mechanical properties. However, the local nanoscale deformation mechanisms are poorly understood. This is due to difficulties of studying this region in 3D under deformation at the nanoscale. Thus, during our previous proposal, we attempted to study the nanoscale of the mouse Achilles tendon enthesis during mechanical testing using texture tomography (TexTOM) at ID15A and phase-contrast microtomography (PC-µCT) at ID19. We successfully saw the nanoscale deformation of different regions in 2D but failed with 3D due to the restrictions of the setup used at the time, which had a too high ‘dose overhead’. To this end, we again propose to use TexTOM and PC-µCT at incremental strain steps, but now with an updated setup at ID15A, reducing exposure with a second fast shutter and faster frames, allowing us to stay within our radiation budget