Osmotic pressure induced tensile forces in tendon collagen
Admir Masic, Luca Bertinetti, Roman Schuetz, Shu-Wei Chang, Till Hartmut Metzger, Markus J Buehler, Peter Fratzl
Changes in hydration can cause collagen to generate powerful pulling forces, potentially affecting how tissues like tendons function.
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.
The episode was first published on the Swedish podcast Fasciaguiden on June 4, 2025. In this unique episode, we meet Professor Gerald Pollack — one of the world’s most influential…
The episode was first published on the Swedish podcast Fasciaguiden on June 5, 2025. In this thought-provoking conversation, we meet Dr. Neil Theise — liver pathologist, fascia re…