Regensburg 2025 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 9: Biomaterials and Biopolymers (joint session BP/CPP)
CPP 9.5: Talk
Monday, March 17, 2025, 16:00–16:15, H46
Encoding how shear stress during gelation boosts the stiffness of collagen networks — •Pavlik Lettinga1,2, Lens Dedroog2, Olivier Deschaume2, Yovan de Coene2, Carmen Bartic2, Erin Koos2, and Mehdi Bouzid3 — 1Forschungszentrum Jülich — 2KU Leuven — 3Université Grenoble Alpes
Collagen is one of the main building blocks of the mammalian extracellular matrix, due to its ability to form tough structures with a wide variety of non-linear mechanical properties allowing it to support multiple tissue types. However, the mechanical properties of collagen gels have been extensively studied under static conditions, whereas in nature gelation will mostly take place in the presence of flow. Here we show how the elastic modulus of collagen hydrogels can be increased up to an order of magnitude by applying a stress ramp at a well-defined moment during gelation. Where the first stress block induces most of the final strain and alignment, sequential increases in stress cause a dramatic increase of the modulus. This high modulus is preserved by keeping the high stress until the gel is fully matured. Coarse-grained simulations of a model gel system show that that the microscopic mechanism of inducing high stiffness is due to formation of extra cross bridges and could be very generic. Thus, we not only show that the true non-linear capabilities of biomaterials are tenfold higher than previously assessed, but also provide insight into in vivo structure formation of collagen and potentially other (bio-)polymers.
Keywords: collagen; shear stress; stress hardening; simulations; confocal microscopy