The cover image is a three dimensional representation of the topography of a hydrated collagen I fibril displaying a localized bend in the otherwise linear structure of the fibril. The color scheme of the image represents the modulus of the fibril with a spatial resolution of 8 nm. The image was generated from data acquired with Peak Force Quantitative Nanomechanical Mapping, an atomic force microscopy mode developed by Bruker. The result of this methodology is a 256 by 256 grid of force curves acquired over a 2 µm x 2 µm region, at indentation speeds of roughly 1 mm/s. This represents an example of recent advancements in mechanical mapping at the nanometer scale in a hydrated environment, and is an essential component for understanding the mechanical properties of biological structures.
The main drive of our research is to understand variations in molecular organization along collagen I fibrils, which are responsible for the mechanical properties of connective tissues such as tendon, ligament, bone, and skin. This image highlights both the localized (fibril bend) and periodic (D-band) fluctuations in molecular interaction and density along the length of a single fibril as depicted in the coloring of the fibril. Our research focus is to study variations in molecular interaction along mechanically damaged collagen fibrils displaying localized alterations. This work will provide insight in to the nanoscale protein response to mechanical damage resulting in the failure of connective tissues.
Further information on our research can be found on our group webpage at:
– Samuel Baldwin, Andrew Quigley, Charlotte Clegg and Laurent Kreplak