Collagen Fibrillar Structure and Hierarchies

Collagen is most commonly found in animals as long, slender generally cylindrical fibrillar structures with tapered ends that are most easily recognized by a 65–67 nm axial periodicity. Collagen fibrils are substantial constituents of skin, tendon, bone, ligament, cornea, and cartilage, where the fundamental tensile properties of the fibril are finely tuned to serve bespoke biomechanical, and less well understood structural signaling roles.