Research

Cell Physics

Scientfic overview

Biophysical properties of cellular compartments

We know from molecular biology that the intracellular space is densely packed. But how dense are cells actually? Through Optical Diffraction Tomography (ODT) we explore density distributions within individual cells, shedding light on how cells organize their sub-compartments in steady-state, and how they restructure it in response to stress.

A significant discovery from our research is that, contrary to common assumptions, the cell nucleus has a lower mass density compared to the cytoplasm. Remarkably, this density ratio remains consistent across various cell types and species, and might be one of the most fundamental organizational principles in cell and developmental biology [Biswas 2023].

 


The mechanical fingerprint of blood

Measurements with our RT-DC device revealed that the major blood cell types can be distinguished by their deformability characteristics [Toepfner 2018]. This innovative technology allows us to analyze whole blood samples and detect variations in blood cell mechanics associated with various diseases. Our findings indicate significant alterations in the mechanical properties of white and red blood cells during conditions such as Covid-19 or depression, among others [Kubanková 2021, Walther 2022]. Even tissue biopsies can be dissociated into single-cell suspensions using a tissue-grinder and then analyzed using RT-DC [Soteriou 2023].

Our ultimate aim is to integrate RT-DC as a standard procedure in clinical practice and to establish cell deformability as a diagnostic marker. To facilitate this transfer, we have many collaborations with colleagues at the University Hospital Erlangen and elsewhere.

 


The mechanics of vertebrate spinal cord regeneration

Unlike humans and other mammals, certain fish species possess the remarkable ability to regenerate their spinal cord following injury, ultimately restoring full motor function. For instance, both adult zebrafish and zebrafish larvae exhibit complete regeneration capabilities. We employ our specialized toolkit to investigate how tissue mechanical properties evolve at the injury site and monitor the regeneration process both in living organisms (in vivo) and in isolated tissue samples (ex vivo) [Schlüßler 2018 , Möllmert 2020, Tsata 2021, Kolb 2023].

Together with the Neuroregeneration Group led by Daniel Wehner, we endeavor to unravel the mystery behind why zebrafish can achieve spinal cord regeneration while humans cannot. This research is part of the CRC1540 Exploring Brain Mechanics.

For a more detailed overview of our research efforts, you can read our reports to the Scientific Advisory Board over the past few years. (report 2020, report 2023).

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