TY - JOUR AU - Salánki, Rita Zsanett AU - Péter, Beatrix AU - Gerecsei, Tamás AU - Orgován, Norbert AU - Horváth, Róbert AU - Szabó, Bálint TI - A practical review on the measurement tools for cellular adhesion force JF - ADVANCES IN COLLOID AND INTERFACE SCIENCE J2 - ADV COLLOID INTERFAC VL - 269 PY - 2019 SP - 309 EP - 333 PG - 25 SN - 0001-8686 DO - 10.1016/j.cis.2019.05.005 UR - https://m2.mtmt.hu/api/publication/30677054 ID - 30677054 LA - English DB - MTMT ER - TY - JOUR AU - Székács, Inna AU - Orgován, Norbert AU - Péter, Beatrix AU - Kovács, Boglárka AU - Horváth, Róbert TI - Receptor specific adhesion assay for the quantification of integrin–ligand interactions in intact cells using a microplate based, label-free optical biosensor JF - SENSORS AND ACTUATORS B-CHEMICAL J2 - SENSOR ACTUAT B CHEM VL - 256 PY - 2018 SP - 729 EP - 734 PG - 6 SN - 0925-4005 DO - 10.1016/j.snb.2017.09.208 UR - https://m2.mtmt.hu/api/publication/3309272 ID - 3309272 LA - English DB - MTMT ER - TY - JOUR AU - Németh, A AU - Orgován, Norbert AU - Sódar, Barbara AU - Osteikoetxea, Xabier AU - Pálóczi, Krisztina AU - Kittel, A AU - Turiák, Lilla AU - Wiener, Zoltán AU - Tóth, Sára AU - Horváth, Róbert AU - Buzás, Edit Irén TI - Antibiotic-induced release of small extracellular vesicles with surfaceassociated DNA JF - JOURNAL OF EXTRACELLULAR VESICLES J2 - J EXTRACELLULAR VESICL VL - 7 PY - 2018 IS - Suppl. 1 SP - 215 EP - 215 PG - 1 SN - 2001-3078 UR - https://m2.mtmt.hu/api/publication/32732704 ID - 32732704 LA - English DB - MTMT ER - TY - JOUR AU - Németh, Andrea AU - Orgován, Norbert AU - Sódar, Barbara AU - Osteikoetxea, Xabier AU - Pálóczi, Krisztina AU - Szabó-Taylor, Katalin AU - Visnovitzné Dr Vukman, Krisztina AU - Kittel, Ágnes AU - Turiák, Lilla AU - Wiener, Zoltán AU - Tóth, Sára AU - Drahos, László AU - Vékey, Károly AU - Horváth, Róbert AU - Buzás, Edit Irén TI - Antibiotic-induced release of small extracellular vesicles (exosomes) with surface-associated DNA JF - SCIENTIFIC REPORTS J2 - SCI REP VL - 7 PY - 2017 IS - 1 PG - 16 SN - 2045-2322 DO - 10.1038/s41598-017-08392-1 UR - https://m2.mtmt.hu/api/publication/3254659 ID - 3254659 AB - Recently, biological roles of extracellular vesicles (which include among others exosomes, microvesicles and apoptotic bodies) have attracted substantial attention in various fields of biomedicine. Here we investigated the impact of sustained exposure of cells to the fluoroquinolone antibiotic ciprofloxacin on the released extracellular vesicles. Ciprofloxacin is widely used in humans against bacterial infections as well as in cell cultures against Mycoplasma contamination. However, ciprofloxacin is an inducer of oxidative stress and mitochondrial dysfunction of mammalian cells. Unexpectedly, here we found that ciprofloxacin induced the release of both DNA (mitochondrial and chromosomal sequences) and DNA-binding proteins on the exofacial surfaces of small extracellular vesicles referred to in this paper as exosomes. Furthermore, a label-free optical biosensor analysis revealed DNA-dependent binding of exosomes to fibronectin. DNA release on the surface of exosomes was not affected any further by cellular activation or apoptosis induction. Our results reveal for the first time that prolonged low-dose ciprofloxacin exposure leads to the release of DNA associated with the external surface of exosomes. LA - English DB - MTMT ER - TY - JOUR AU - Salánki, Rita Zsanett AU - Gerecsei, Tamás AU - Fürjes, Péter AU - Orgován, Norbert AU - Sándor, Noémi AU - Holczer, Eszter Gabriella AU - Horváth, Róbert AU - Szabó, Bálint TI - Automated single cell isolation from suspension with computer vision JF - SCIENTIFIC REPORTS J2 - SCI REP VL - 6 PY - 2016 PG - 9 SN - 2045-2322 DO - 10.1038/srep20375 UR - https://m2.mtmt.hu/api/publication/2991783 ID - 2991783 AB - Current robots can manipulate only surface-attached cells seriously limiting the fields of their application for single cell handling. We developed a computer vision-based robot applying a motorized microscope and micropipette to recognize and gently isolate intact individual cells for subsequent analysis, e.g., DNA/RNA sequencing in 1–2 nanoliters from a thin (~100 μm) layer of cell suspension. It can retrieve rare cells, needs minimal sample preparation and can be applied for virtually any tissue cell type. Combination of 1 μm positioning precision, adaptive cell targeting and below 1 nl liquid handling precision resulted in an unprecedented accuracy and efficiency in robotic single cell isolation. Single cells were injected either into the wells of a miniature plate with a sorting speed of 3 cells/min or into standard PCR tubes with 2 cells/min. We could isolate labeled cells also from dense cultures containing ~1,000 times more unlabeled cells by the successive application of the sorting process. We compared the efficiency of our method to that of single cell entrapment in microwells and subsequent sorting with the automated micropipette: the recovery rate of single cells was greatly improved. LA - English DB - MTMT ER - TY - JOUR AU - Nazirizadeh, Yousef AU - Behrends, Volker AU - Prósz, György Aurél AU - Orgován, Norbert AU - Horváth, Róbert AU - M Ferrie, Ann AU - Fang, Ye AU - Selhuber-Unkel, Christine AU - Gerken, Martina TI - Intensity interrogation near cutoff resonance for label-free cellular profiling JF - SCIENTIFIC REPORTS J2 - SCI REP VL - 6 PY - 2016 PG - 6 SN - 2045-2322 DO - 10.1038/srep24685 UR - https://m2.mtmt.hu/api/publication/3055425 ID - 3055425 AB - We report a method enabling intensity-based readout for label-free cellular assays and realize a reader device with the same footprint as a microtiter plate. For unambiguous resonance intensity measurements in resonance waveguide grating (RWG) sensors, we propose to apply resonances near the substrate cutoff wavelength. This method was validated in bulk refractive index, surface bilayer and G protein-coupled receptor (GPCR) experiments. The significantly reduced size of the reader device opens new opportunities for easy integration into incubators or liquid handling systems. LA - English DB - MTMT ER - TY - GEN AU - Kovács, Boglárka AU - Patkó, Dániel AU - Székács, Inna AU - Orgován, Norbert AU - Kurunczi, Sándor AU - Toth, Balazs AU - Vonderviszt, Ferenc AU - Horváth, Róbert TI - The modulation of human cell adhesion by genetically modified flagellin monolayers revealed by label-free optical biosensors PY - 2016 UR - https://m2.mtmt.hu/api/publication/3078629 ID - 3078629 LA - English DB - MTMT ER - TY - GEN AU - Kovács, Boglárka AU - Orgován, Norbert AU - Patkó, Dániel AU - Székács, Inna AU - Kurunczi, Sándor AU - Toth, Balazs AU - Vonderviszt, Ferenc AU - Horváth, Róbert TI - The modulation of human cell adhesion by oriented flagellin monolayers revealed by label-free optical biosensors PY - 2016 UR - https://m2.mtmt.hu/api/publication/3078634 ID - 3078634 LA - English DB - MTMT ER - TY - JOUR AU - Orgován, Norbert AU - Salánki, Rita Zsanett AU - Lukácsi, Szilvia Zsófia AU - Sándor, Noémi AU - Bajtay, Zsuzsanna AU - Erdei, Anna AU - Szabó, Bálint AU - Horváth, Róbert TI - Adhesion kinetics of human primary monocytes, dendritic cells, and macrophages: Dynamic cell adhesion measurements with a label-free optical biosensor and their comparison with end-point assays JF - BIOINTERPHASES J2 - BIOINTERPHASES VL - 11 PY - 2016 IS - 3 PG - 11 SN - 1934-8630 DO - 10.1116/1.4954789 UR - https://m2.mtmt.hu/api/publication/3095711 ID - 3095711 AB - Monocytes, dendritic cells (DCs), and macrophages (MFs) are closely related immune cells that differ in their main functions. These specific functions are, to a considerable degree, determined by the differences in the adhesion behavior of the cells. To study the inherently and essentially dynamic aspects of the adhesion of monocytes, DCs, and MFs, dynamic cell adhesion assays were performed with a high-throughput label-free optical biosensor [Epic BenchTop (BT)] on surfaces coated with either fibrinogen (Fgn) or the biomimetic copolymer PLL-g-PEG-RGD. Cell adhesion profiles typically reached their maximum at ∼60 min after cell seeding, which was followed by a monotonic signal decrease, indicating gradually weakening cell adhesion. According to the biosensor response, cell types could be ordered by increasing adherence as monocytes, MFs, and DCs. Notably, all three cell types induced a larger biosensor signal on Fgn than on PLL-g-PEG-RGD. To interpret this result, the molecular layers were characterized by further exploiting the potentials of the biosensor: by measuring the adsorption signal induced during the surface coating procedure, the authors could estimate the surface density of adsorbed molecules and, thus, the number of binding sites potentially presented for the adhesion receptors. Surfaces coated with PLL-g-PEG-RGD presented less RGD sites, but was less efficient in promoting cell spreading than those coated with Fgn; hence, other binding sites in Fgn played a more decisive role in determining cell adherence. To support the cell adhesion data obtained with the biosensor, cell adherence on Fgn-coated surfaces 30–60 min after cell seeding was measured with three complementary techniques, i.e., with (1) a fluorescence-based classical adherence assay, (2) a shear flow chamber applying hydrodynamic shear stress to wash cells away, and (3) an automated micropipette using vacuum-generated fluid flow to lift cells up. These techniques confirmed the results obtained with the high-temporal-resolution Epic BT, but could only provide end-point data. In contrast, complex, nonmonotonic cell adhesion kinetics measured by the high-throughput optical biosensor is expected to open a window on the hidden background of the immune cell–extracellular matrix interactions. LA - English DB - MTMT ER - TY - JOUR AU - Kovács, Boglárka AU - Patkó, Dániel AU - Székács, Inna AU - Orgován, Norbert AU - Kurunczi, Sándor AU - Sulyok, Attila AU - Nguyen Quoc, Khánh AU - Toth, B AU - Vonderviszt, Ferenc AU - Horváth, Róbert TI - Flagellin based biomimetic coatings: From cell-repellent surfaces to highly adhesive coatings JF - ACTA BIOMATERIALIA J2 - ACTA BIOMATER VL - 42 PY - 2016 SP - 66 EP - 76 PG - 11 SN - 1742-7061 DO - 10.1016/j.actbio.2016.07.002 UR - https://m2.mtmt.hu/api/publication/3105834 ID - 3105834 AB - Biomimetic coatings with cell-adhesion-regulating functionalities are intensively researched today. For example, cell-based biosensing for drug development, biomedical implants, and tissue engineering require that the surface adhesion of living cells is well controlled. Recently, we have shown that the bacterial flagellar protein, flagellin, adsorbs through its terminal segments to hydrophobic surfaces, forming an oriented monolayer and exposing its variable D3 domain to the solution. Here, we hypothesized that this nanostructured layer is highly cell-repellent since it mimics the surface of the flagellar filaments. Moreover, we proposed flagellin as a carrier molecule to display the cell-adhesive RGD (Arg-Gly-Asp) peptide sequence and induce cell adhesion on the coated surface. The D3 domain of flagellin was replaced with one or more RGD motifs linked by various oligopeptides modulating flexibility and accessibility of the inserted segment. The obtained flagellin variants were applied to create surface coatings inducing cell adhesion and spreading to different levels, while wild-type flagellin was shown to form a surface layer with strong anti-adhesive properties. As reference surfaces synthetic polymers were applied which have anti-adhesive (PLL-g-PEG poly(L-lysine)-graft-poly(ethylene glycol)) or adhesion inducing properties (RGD-functionalized PLL-g-PEG). Quantitative adhesion data was obtained by employing optical biochips and microscopy. Cell-adhesion-regulating coatings can be simply formed on hydrophobic surfaces by using the developed flagellin-based constructs. The developed novel RGD-displaying flagellin variants can be easily obtained by bacterial production and can serve as alternatives to create cell-adhesion-regulating biomimetic coatings. Statement of Significance In the present work, we show for the first time that - an oriented and dense monolayer of flagellin molecules mimics the surface of the bacterial flagellar filament. Consequently, the fabricated layer is completely cell repellent.- By genetically modifying flagellin, we incorporate cell adhesion regulating functionalities into this anti-adhesive coating.- We can easily tune the adhesion of living cells from completely cell repellent to highly adhesive. © 2016 Acta Materialia Inc. LA - English DB - MTMT ER -