Összes szerző

Sallai Igor

az alábbi absztraktok szerzői között szerepel:

Novák Szabolcs
Investigation of antibody-mediated adhesion force of individual immune cells using computer-controlled micropipette and fluidic force microscopy

Aug 29 - kedd

15:30 – 17:00

I. Poszterszekció

P19

Investigation of antibody-mediated adhesion force of individual immune cells using computer-controlled micropipette and fluidic force microscopy

S. Novák¹, Z. Szittner¹, I. Sallai¹, I. Székács¹, R. Horvath¹

¹ Nanobiosensorics Laboratory, Centre of Energy Research, Eötvös Loránd Research Network, Budapest, Hungary

Cell adhesion is a fundamental process that plays a critical role in various biological phenomena, such as the immune response. To understand the mechanisms of cell adhesion and develop new therapies, it is necessary to measure the forces involved.Computer-controlled micropipettes (CCMP) and Fluidic Force Microscopy (FluidFM) techniques have become effective instruments for the accurate determination of cell adhesion in recent years.

A CCMP is a tool that can be used to probe single cell interactions with specific macromolecules and surfaces. The micropipette is mounted onto a micromanipulator on a normal inverted microscope and is controlled by a computer. The adhesion force of surface-attached cells can be accurately probed by repeating a pick-up process on the examined cells while increasing a vacuum applied through a pump system in the pipette positioned above the cell. Using this methodology, high number of cells adhered to specific macromolecules, treated surfaces can be measured one by one in a short period of time. Additionally, the probed single cells can be easily picked up and separated for further examinations by other techniques. This is a definite advantage of the CCPM.[1]

FluidFM, on the other hand, uses a hollow cantilever with a small opening at the tip that can be filled with liquid using a fluid reservoir that is attached to a pressure control system, allowing for precise fluid dispensing and manipulation at the nanoscale. This technology enables the precise measurement of adhesion forces between cells and their targets and makes it possible to record the entire cell detachment process quickly and accurately. [2]

The combination of these two technologies provides high accuracy and resolution in the measurement of cell adhesion forces and in addition to measuring adhesion forces. We used these techniques to study the adhesion strength of immune cells on different surfaces.

Acknowledgment

This work was supported by the National Research, Development, and Innovation Office (Grant Numbers: PD 134195 for Z.Sz, ELKH topic-fund, "Élvonal" KKP_19 TKP2022-EGA-04 grants).

References

[1] R. Salánki et al., “Single Cell Adhesion Assay Using Computer Controlled Micropipette,” PLoS One, vol. 9, no. 10, pp. e111450-, Oct. 2014, [Online]. Available: https://doi.org/10.1371/journal.pone.0111450

[2] Á. G. Nagy, I. Székács, A. Bonyár, and R. Horvath, “Cell-substratum and cell-cell adhesion forces and single-cell mechanical properties in mono- and multilayer assemblies from robotic fluidic force microscopy,” Eur J Cell Biol, vol. 101, no. 4, Sep. 2022, doi: 10.1016/j.ejcb.2022.151273.

Sallai Igor
Label-free immune cell analysis using optical biosensor

Aug 30 - szerda

15:30 – 17:00

II. Poszterszekció

P52

Label-free immune cell analysis using optical biosensor

I. Sallai¹, Z. Szittner¹, Sz. Novák¹, I. Székács¹ and R. Horvath¹

¹ Nanobiosensorics Laboratory, Center of Energy Research, Eötvös Loránd Research Network, Budapest, Hungary

Understanding of activation processes at the single-cell level in response to different stimuli is essential for the diagnosis of certain diseases.

External stimuli induced differences are reflected in the dynamic changes of cell biophysical parameters, such as cell motility, shape, spreading and adhesion properties [1]. Novel highly sensitive optical biosensors allow the monitoring of changes in these parameters in a label-free manner. The advantage of label-free detection is that cells can be examined in an intact/organism-specific manner without modification.

The above parameters can be studied using microplate-based, high-throughput systems [2]. Surface functionalisation provide the opportunity to create an organism-specific environment [3]. In classical measurements, such as microscopy, dye-conjugated antibody labelling is essential and can be combined with label-free data [4].

Our aim is to interpret the activation mechanisms of various cell types and their function triggered by different stimuli and compare the results with conventional testing methods.

Acknowledgment

This work was supported by the National Research, Development, and Innovation Office (Grant Numbers: PD 134195 for Z.Sz, ELKH topic-fund, "Élvonal" KKP_19 TKP2022-EGA-04 grants).

References

[1] Z. Szittner, B. Péter, S. Kurunczi, I. Székács, and R. Horvath, “Functional blood cell analysis by label-free biosensors and single-cell technologies,” Advances in Colloid and Interface Science, vol. 308. Elsevier B.V., Oct. 01, 2022. doi: 10.1016/j.cis.2022.102727.

[2] M. Sztilkovics et al., “Single-cell adhesion force kinetics of cell populations from combined label free optical biosensor and robotic fluidic force microscopy,” Sci Rep, vol. 10, no. 1, Dec. 2020, doi: 10.1038/s41598-019-56898-7.

[3] N. Orgovan et al., “In-situ and label-free optical monitoring of the adhesion and spreading of primary monocytes isolated from human blood: Dependence on serum concentration levels,” Biosens Bioelectron, vol. 54, pp. 339–344, Apr. 2014, doi: 10.1016/j.bios.2013.10.076.

[4] S. Zheng, J. C. H. Lin, H. L. Kasdan, and Y. C. Tai, “Fluorescent labeling, sensing, and differentiation of leukocytes from undiluted whole blood samples,” Sens Actuators B Chem, vol. 132, no. 2, pp. 558–567, Jun. 2008, doi: 10.1016/j.snb.2007.11.031.

Szittner Zoltán
Label-free single-cell compatible biophysical methods in immune cell activation

Aug 30 - szerda

12:00 – 12:15

Bioszenzorika és bio-nanotechnológia

E30

Label-free single-cell compatible biophysical methods in immune cell activation

Z. Szittner, S. Novák, I. Sallai, I. Székács, R. Horvath

Nanobiosensorics Laboratory, Centre of Energy Research, ELKH, Budapest, Hungary

Recent advances in biophysical methods provide a novel approach to characterize immune cell activation. Here, we present an experimental platform for studying adhesion kinetics, adhesion force, and cell morphology at a single-cell level. These techniques enable the precise characterization of complex cellular mixtures and the testing of the effects of various compounds on immune cell activation(1). The adhesion force, measured by computer-controlled micropipette and fluidic force microscopy, serves as a proxy for cellular activation induced by various compounds(2). The resonant wavelength grating technique exploits the sensitivity of the surface-bound optical evanescent field to changes in the local refractive index, enabling the study of cell adhesion kinetics in single cells at subminute time resolutions(3). Moreover, digital holographic microscopy records the morphology of single cells during their activation and extracts multiple features, such as cell area, optical thickness, and motility, to characterize their activation state(4). Importantly, these biophysical methods enable the characterization of cellular processes in a label-free manner, reducing the complexity and material demand of each measurement and enabling the investigation of single cells in their native state. Comparing and evaluating these techniques carefully can enhance our understanding of immune cell activation and lead to the development of diagnostic approaches and novel therapies for immune system-related questions.

Acknowledgements

This work was supported by the National Research, Development, and Innovation Office (Grant Numbers: PD 134195 for Z.Sz, PD 131543 for B.P., ELKH topic-fund, "Élvonal" KKP_19 TKP2022-EGA-04 grants).

References

1. Szittner Z, Péter B, Kurunczi S, Székács I, Horvath R. Functional blood cell analysis by label-free biosensors and single-cell technologies. Advances in Colloid and Interface Science. 2022 Oct;308:102727.

2. Ungai-Salánki R, Peter B, Gerecsei T, Orgovan N, Horvath R, Szabó B. A practical review on the measurement tools for cellular adhesion force. Advances in Colloid and Interface Science. 2019 Jul 1;269:309–33.

3. Sztilkovics M, Gerecsei T, Peter B, Saftics A, Kurunczi S, Szekacs I, et al. Single-cell adhesion force kinetics of cell populations from combined label-free optical biosensor and robotic fluidic force microscopy. Sci Rep. 2020 Jan 9;10(1):61.

4. Nagy ÁG, Székács I, Bonyár A, Horvath R. Simple and automatic monitoring of cancer cell invasion into an epithelial monolayer using label-free holographic microscopy. Sci Rep. 2022 Jun 16;12(1):10111.