Berlin 2024 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 33: Focus session: Physics of organoids
BP 33.5: Vortrag
Donnerstag, 21. März 2024, 16:30–16:45, H 1028
Quantification of mechanical relaxation in retinal organoid tissues across scales — •Elijah Robinson Shelton1, Michael Frischmann1, Achim Theo Brinkop1, Rebecca James1, and Friedhelm Serwane1,2 — 1Faculty of Physics and Center for NanoScience, LMU Munich, Germany — 2SyNergy, LMU Munich, Germany
Quantifying mechanical properties is critical for understanding how forces shape tissues during retinal development. Organoids recapitulate retina composition and morphology, providing physicists with a platform to study the mechanics underlying this self-organization. While retina mechanical properties have been investigated with various technologies, such probing has been restricted to timescales of seconds or less. Using retina organoids as in vitro models and ferrofluid droplets as force actuators, we probe retina rheology over a range of timescales. After we inject ferrofluid droplets (30 microns), we live-image organoids on a confocal microscope. We introduce homogenous magnetic fields to actuate the droplets and the tissue. Using linear viscoelastic models, we find a mean elastic modulus of 0.63 kPa when probed at a second timescale. We find viscosities of 4.5 to 15.1 kPa s for strain responses over 5 to 20 minutes, indicating stress relaxation over a range of timescales. To describe this rheology across scales, we employ fractional viscoelastic models and discuss their application to retinal organoid tissue mechanics. This modeling combined with our experimental observations provide mechanical insights for how the retina is shaped during development in vivo and in vitro.
Keywords: Tissue mechanics; Organoids; Viscoelasticity; Retina; Magnetic droplets