Osmotic pressure induced tensile forces in tendon collagen

Abstract

Water is an important component of collagen in tendons, but its role for the function of this load-carrying protein structure is poorly understood. Here we use a combination of multi-scale experimentation and computation to show that water is an integral part of the collagen molecule, which changes conformation upon water removal. The consequence is a shortening of the molecule that translates into tensile stresses in the range of several to almost 100 MPa, largely surpassing those of about 0.3 MPa generated by contractile muscles. Although a complete drying of collagen would be relevant for technical applications, such as the fabrication of leather or parchment, stresses comparable to muscle contraction already occur at small osmotic pressures common in biological environments. We suggest, therefore, that water-generated tensile stresses may play a role in living collagen-based materials such as tendon or bone.

Gradual conversion of cellular stress patterns into pre-stressed matrix architecture during in vitro tissue growth

“…Interface 13: 20160136 pre-strain in the ECM fibrils behind the growth front. Recent studies discovered how stresses up to several megapascals in collagen can develop purely owing to changes in osmotic pressure in ranges that can occur in the presence of PGs in the ECM [72]. Although we have not yet investigated the role of PGs on the development of ECM tension in our in vitro system, it presents a plausible mechanism by which ECM internal stresses can be pre-programmed by cells.…”

Wall structure and material properties cause viscous damping of swimbladder sounds in the oyster toadfishOpsanus tau

“…Findings from the current study indicate that the bladder wall is responsible for differences between findings and predictions of the underwater resonant bubble. Further, water content appears important for normal acoustic function [52]. The high water content, decreased RE and increased RS and modulus in dry bladder tissue strongly implicate viscous damping.…”

Interfibrillar stiffening of echinoderm mutable collagenous tissue demonstrated at the nanoscale

“…3A. In this regard, the recent finding of collagen molecular shortening-due to water content changes-leading to large tensile stresses in tendon may be of relevance (59). These findings shed light on the synergistic action at the nanoscale enabling mutability in MCT.…”