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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 41: Biopolymers, Biomaterials and Bioinspired Functional Materials II (joint session CPP/BP)
CPP 41.5: Vortrag
Mittwoch, 29. März 2023, 17:30–17:45, MER 02
Aging and compressed exponential stress relaxation in mechanoresponsive hydrogels — •Geonho Song1,2, Wouter Ellenbroek3, and Kerstin Blank1,2 — 1Johannes Kepler University Linz, Linz, Austria — 2Max Planck Institute of Colloids and Interfaces, Potsdam, Germany — 3Eindhoven University of Technology, Eindhoven, The Netherlands
Biological materials, such as the extracellular matrix (ECM), are viscoelastic and exhibit stress relaxation. Stress relaxation in the ECM is linked to cellular behavior and needs to be considered as a design parameter when developing bioinspired materials for cell culture and tissue engineering. Here, we introduce a collagen-inspired hydrogel with tunable crosslink kinetics. We utilize collagen-mimetic peptides with controlled association and dissociation rates to crosslink star-shaped polyethylene glycol. We show that ultraslow crosslink dissociation rates cause a distinctive relaxation behavior that is reminiscent of soft glassy materials, showing out-of-equilibrium properties. In particular, subjecting the networks to a sequence of pre-stress and aging causes uncommon compressed exponential relaxation. This unique phenomenon has previously only been reported for a small number of soft glassy systems where compressed exponential relaxation was related to ultraslow dynamics that prohibited the release of internal stresses. In such systems, slow crosslink dissociation delays network relaxation until an external trigger is applied. In future work, we aim to investigate the interplay between locally generated stresses, such as cellular traction forces, and network relaxation properties.