ALT Tissues are perpetually subjected to mechanical forces. We know for nearly a century that high mechanical load on polymer materials - be it a shoe sole or rubber band – causes the rupture of chemical bonds and generates mechanoradicals. We uncovered the very same mechanism in biology: radicals form by stretching collagen, a major protein material of our tissues, even under stresses far below tissue failure. Using experiments in conjunction with simulations and machine learning we reveal how collagen tames its radicals and converts them in a highly controlled fashion to oxidative stress, dominantly hydrogen peroxide. We currently explore how this new mechano-sensing mechanism is related to tissue inflammation and ageing.
ALT Winners of the 2024 Paul Klee Awards. On the left Dr. Salome Brütsch and on the right Dr. Catharina Sänger, with flowers and their award certificates.
ALT Winners of the 2024 Paul Klee Awards. On the left Dr. Salome Brütsch and on the right Dr. Catharina Sänger, with flowers and their award certificates.
ALT Macroscopic analysis of HSEs shows an effect of radial constraint. a) Representative macroscopic images (upper panel) and hematoxylin & eosin (H&E)-stained cross-sections (lower panel) of HSEs from all experimental groups after 26 days of culture: Planar constraint (PC), free-floating (FF), radial constraint S (RC-S), radial constraint M (RC-M) and radial constraint L (RC-L). The depicted arrow points to the location of the 3D-printed culture insert. Scale bars; 10 mm for macroscopic images and 2 mm for H&E cross-sections. b) Epidermal thickness of the produced HSEs after 26 days of culture was measured in H&E-stained sections. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001. c) Dermal thickness of the produced HSEs after 26 days of culture was measured in H&E-stained sections. *P < 0.05 and **P < 0.01 (Kruskal-Wallis test with Dunn's multiple comparison test). d) Radial area contraction of HSEs over the total culture period (26 days). Graphs show mean ± standard deviation.
