Unlocking the secrets of cell adhesion

Originally, our Nanobiosensorics Laboratory focused on the development and application of optical biosensors for live cell studies. One of our primary interests was the adhesion of living cells, particularly integrin complexes, their time-dependent assembly, and how external factors or components of the cell surface glycocalyx influence these biological processes. There were very few techniques available that could study these processes in living cells without labeling, especially once mature adhesion contacts were formed.

FluidFM technology emerged as one of these techniques, and our interest in it grew after reading the excellent papers by Tomasso, Janos, and their colleagues at ETH. When Janos first mentioned the robotic FluidFM system, OMNIUM, to me, I immediately recognized it as the technique we needed. The system offered significantly higher throughput compared to conventional AFM or FluidFM, thanks to its motorized large-area sample stage. I also envisioned combining the Omnium system with our large-area optical biosensors, allowing us to simultaneously measure the optical signals and adhesion force of the same living cell.

Since incorporating FluidFM into our research, it has profoundly influenced the way we approach our work. The increased throughput provided by the Omnium system has allowed us to gather data from a larger number of living cells, enhancing the statistical significance of our findings. Additionally, the ability to measure both optical signals and adhesion force in real-time has provided a more comprehensive understanding of the cellular adhesion process. This integrated approach has opened up new avenues for investigating the dynamic behavior of integrin complexes and their interaction with the cell environment.

Overall, FluidFM technology has revolutionized our experimental capabilities and significantly advanced our research in studying live cell adhesion. It has provided a valuable tool for exploring the intricate details of cellular processes without the need for labeling, enabling us to uncover novel insights into the mechanisms underlying cell adhesion and its regulation.

We have achieved numerous successful projects utilizing FluidFM technology, including applications beyond the field of cell adhesion. One notable accomplishment involved the precise printing of cell adhesion peptide motifs on a biomimetic DEXTRAN-based interface using FluidFM microprobes. We meticulously calibrated the optical signals of adhering living cancer cells to correspond with adhesion force. Leveraging this force-calibrated label-free sensor, we were able to determine the adhesion force distribution of large cell populations, shedding light on time-dependent population changes. Additionally, we delved into investigating the cell cycle of cancer cells and expanded our research to more complex systems, such as epithelial layers with adhering cancer cells on top. Furthermore, we successfully employed microbeads and FluidFM to force-calibrate another high-throughput device, the computer-controlled micropipette, for applications in colloidal force spectroscopy.

These endeavors highlight the versatility and effectiveness of FluidFM technology in diverse research areas. By leveraging its capabilities, we have been able to conduct intricate experiments, uncovering valuable insights into cellular processes and exploring novel applications beyond traditional cell adhesion studies.

In my view, FluidFM has the potential to become a standard tool in both cell biology and biotechnological laboratories, as well as in labs focused on cell mechanics and biophysics. Its versatility allows for successful application in diverse areas of research. In our own work, we have already begun utilizing FluidFM for injecting various nanoparticles into living cells and studying their subsequent fate. This expansion of capabilities opens up exciting possibilities for investigating cellular processes at a more detailed level.

Furthermore, the recently introduced Live-seq technique by the research groups of Vorholt at ETH and Deplancke at EPFL is expected to facilitate the transfer of other omics technologies, such as proteomics and metabolomics, from their current end-point-type assays to a temporal analysis platform. This advancement has the potential to revolutionize biology as a whole, enabling researchers to gain deeper insights into the dynamic processes governing life.

Looking ahead, I anticipate that FluidFM technology will continue to advance, offering improved precision, higher throughput, and expanded applications. This will greatly impact our research by providing us with enhanced tools for studying cell behavior, cellular interactions, and the underlying mechanisms in greater detail. Additionally, the field as a whole will benefit from the continued evolution of FluidFM technology, as it will contribute to groundbreaking discoveries and further our understanding of biological processes at the cellular level.

Robert Horvath is a physicist specializing in biophysics. He received his MSc and PhD degrees from Eötvös University, Hungary, in 1997 and 2002, respectively. During his PhD studies, he focused on developing an OWLS biosensor and applying the technique to various problems in biophysics and biology. As a visiting PhD student at the Graduate School of Biophysics (Copenhagen University, Denmark), he gained experience in micro- and nano-fabrication of polymeric materials and conducted theoretical and experimental work on novel waveguide sensor configurations, including the reverse symmetry waveguide.

     Starting in November 2001, he worked as a postdoctoral researcher in the Optics and Plasma Research Department at the Risø National Laboratory in Denmark, where he developed advanced biosensors for bacterial detection. In 2004, he received a two-year Talent Project Award from the Danish Technical Research Council to investigate surface-cell interactions in bioassays. From 2006, he held a Marie Curie EIF Fellowship at Cranfield University, England, working on the OPTICELL project. This project focused on studying protein structural order, surface adsorption, and stem cell adhesion and behavior on nanosurfaces using label-free optical biosensors under the guidance of Professor Jeremy J Ramsden.

     Robert received a three-year fellowship from the Hungarian Scientific Research Fund (OTKA) and a Marie Curie Reintegration Grant to join the Photonics Division of MFA from October 2008. In 2012, he was awarded the Momentum Award for Excellence by the Hungarian Academy of Sciences and became the head of the Nanobiosensorics Laboratory. The laboratory's activities encompass all aspects of label-free biosensing, ranging from theory to device fabrication and future applications, such as the detection and characterization of protein and polyelectrolyte multilayer films, bacteria, and living cells. Their present focus is on single-cell label-free biosensing and manipulation using resonant waveguide gratings, FluidFM, and computer-controlled micropipette.

For more information, please visit  www.nanobiosensorics.com.