Investigating the biophysical response of suspension cells to a millisecond osmotic stress

• Applicant: Professor Dr. Oliver Otto
• Subject Area: Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics ; Biophysics
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 555508590

The central goal of this proposal is to study the biophysical response of suspended cells to an osmotic stress on a millisecond timescale. Answering this fundamental question might help to better understand, e.g., how blood cells cope with the osmolarity gradient in the vasa recta of the human kidney or how leukocytes detect tissue damage by osmotic surveillance. Experiments will be carried out in microfluidic systems using virtual fluidic channels and readout will be based on biophysical cell properties, i.e., cell deformation, cell size (area and volume), cell elasticity and cell viscosity. In detail, the project aims toanswer the following questions:1. On a millisecond timescale, what is the biophysical response of suspended cells to a hyperosmotic and a hypoosmotic stress? 2. Does this response depend on the magnitude of the osmotic stress? 3. What are characteristic times of an osmotic stress response? 4. What is the limiting factor for the rate of volume exchange? Is it found in the cell membrane or in the poroelasticity of the cytoplasm? 5. What is the impact of the osmotically-active surface on the osmotic stress response of cells?

• DFG Programme: Research Grants
• International Connection: United Kingdom
• Cooperation Partner: Dr. Marta Urbanska