Jure Derganc, Assoc. Prof. in Biophysics at the Faculty of Medicine, University of Ljubljana, Slovenia

Leuchs-Russell-Auditorium, A.1.500, Staudtstr. 2

Location details

Abstract:

Mechanical properties are an important parameter of living cells reflecting their function and potential pathologies. In recent years, a number of experimental methods have been developed to assess cell mechanics, but so far none of them has found its way into clinical practice. For example, we have recently developed a new method, which employs optical tweezers to measure the surface stiffness of adherent cells [1,2]. The method was applied to different cell types and showed that the disruption of cytoskeletal elements affects the stiffness of the cell surface and the cell interior differently [3]. However, the method is very labor-intensive and has not been adopted by other laboratories. To study non-adherent cells, we have turned to deformability cytometry, which was recently developed by the Guck group. We intend to use this method to assess the health of immune cells used in cell immunotherapies such as CAR-T therapy. To test the method, we used a custom-built, low-cost stroboscopic imaging system [4] and focused on the Jukrat cell line as the standard lymphocyte model. The goal was to determine if the cells are affected by the presence of the lipid emulsions Omegaven and SMOFlipid, which are part of parenteral nutrition for critically ill patients. In my talk, I will present our unpublished results on Jurkat cells and discuss some of the challenges we have faced with deformability cytometry that need to be resolved before this method can be adopted in the clinical setting, e.g. open access to the methods used for image analysis and machine learning for cell classification.

[1] Zemljič Jokhadar, Š., Stojković, B., Vidak, M., Sorčan, T., Liovic, M., Gouveia, M., ... & Derganc, J. (2020). Cortical stiffness of keratinocytes measured by lateral indentation with optical tweezers. Plos one, 15(12), e0231606.

[2] Zemljič-Jokhadar, Š., Kokot, G., Pavlin, M., & Derganc, J. (2021). Adhesion and stiffness of detached breast cancer cells in vitro: Co-treatment with metformin and 2-deoxy-D-glucose induces changes related to increased metastatic potential. Biology, 10(9), 873.

[3] Zemljič Jokhadar, Š., Iturri, J., Toca-Herrera, J. L., & Derganc, J. (2021). Cell stiffness under small and large deformations measured by optical tweezers and atomic force microscopy: effects of actin disruptors CK-869 and jasplakinolide. Journal of Physics D: Applied Physics, 54(12), 124001.

[4] Tuljak, M., Lajevec, D., Zemljič Jokhadar, Š., & Derganc, J. (2022). Low-cost programable stroboscopic illumination with sub-microsecond pulses for high-throughput microfluidic applications. HardwareX, 12, e00367.