Determination of the elastic modulus of native collagen fibrils via radial indentation

The authors studied the elastic response of single, native collagen fibrils extracted from tissues of the inner dermis of the sea cucumber, Cucumaria frondosa, via local nanoscale indentation with an atomic force microscope (AFM). AFM imaging of fibrils under ambient conditions are presented, demonstrating a peak-to-peak periodicity, the d band, of dehydrated, unfixed fibrils to be ∼64.5nm. Radial indentation experiments were performed, and the measured value for the reduced modulus is 1–2GPa.