Promotionsvortrag Physik: „On the viscoelasticity and the circulation behavior of cells“

Ankündigung des Promotionsvortrags von: Herrn Benedikt Hartmann

The viscoelastic properties of biological cells are crucial for understanding cellular behavior in both healthy and diseased states. Microfluidics has emerged as a powerful tool for studying these properties, though challenges remain, particularly in analyzing complex stress distributions and maintaining cells in the imaging focal plane.

To address this, I introduce a novel approach using hyperbolic channels combined with 3D hydro-dynamic focusing. This setup simplifies the stress distribution and keeps cells centered in the channel, enabling the use of calibration particles to characterize the stresses in the channel with-out the need to determine different stress contributions or the carrier medium’s rheology. Using this method, I applied Kelvin-Voigt and power-law models to extract the mechanical properties of human leukemia HL60 cells.

In the second part of my work, I explore how the viscoelasticity of cells relate to their transit through constriction channels - relevant in microcirculation, where blood cells regularly deform to pass through narrow capillaries. Unlike previous studies that either focus on single constrictions or measure transit times without linking them to viscoelasticity, my research connects both aspects. The data suggest that initial deformation facilitates passage through subsequent constrictions and that the time scale matters.

Overall, these findings provide new insights into cellular viscoelasticity, its role in microcirculation, and may improve our understanding of cells.

(Vortrag auf Englisch)

Dem Vortrag schließt sich eine Diskussion von 15 Minuten an. Vortrag und Diskussion sind öffentlich. Diesen Verfahrensteilen folgt ein nicht öffentliches Rigorosum von 45 Minuten.