1
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Linder A, Portmann K, Schlotheuber LJ, Streuli A, Glänzer WS, Eyer K, Lüchtefeld I. Microfluidic Approach to Resolve Simultaneous and Sequential Cytokine Secretion of Individual Polyfunctional Cells. J Vis Exp 2024. [PMID: 38526129 DOI: 10.3791/66492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2024] Open
Abstract
Infections, autoimmune diseases, desired and adverse immunological responses to treatment can lead to a complex and dynamic cytokine response in vivo. This response involves numerous immune cells secreting various cytokines to orchestrate the immune reaction. However, the secretion dynamics, amounts, and co-occurrence of the different cytokines by various cell subtypes remain poorly understood due to a lack of appropriate tools to study them. Here, we describe a protocol using a microfluidic droplet platform that allows the time-resolved quantitative measurement of secretion dynamics for several cytokines in parallel on the single-cell level. This is enabled by the encapsulation of individual cells into microfluidic droplets together with a multiplexed immunoassay for parallel quantification of cytokine concentrations, their immobilization for dynamic fluorescent imaging, and the analysis of the respective images to derive secreted quantities and dynamics. The protocol describes the preparation of functionalized magnetic nanoparticles, calibration experiments, cell preparation, and the encapsulation of the cells and nanoparticles into droplets for fluorescent imaging and subsequent image and data analysis using the example of lipopolysaccharide-stimulated human peripheral blood mononuclear cells. The presented platform identified distinct cytokine secretion behavior for single and co-secreting cells, characterizing the expected phenotypic heterogeneity in the measured cell sample. Furthermore, the modular nature of the assay allows its adaptation and application to study a variety of proteins, cytokines, and cell samples, potentially leading to a deeper understanding of the interplay between different immune cell types and the role of the different cytokines secreted dynamically to shape the tightly regulated immune response. These new insights could be particularly interesting in the studies of immune dysregulations or in identifying target populations in therapy and drug development.
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Affiliation(s)
- Aline Linder
- Laboratory for Functional Immune Repertoire Analysis, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zürich
| | - Kevin Portmann
- Laboratory for Functional Immune Repertoire Analysis, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zürich
| | - Luca Johannes Schlotheuber
- Laboratory for Functional Immune Repertoire Analysis, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zürich
| | - Alessandro Streuli
- Laboratory for Functional Immune Repertoire Analysis, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zürich
| | - Wiona Sophie Glänzer
- Laboratory for Functional Immune Repertoire Analysis, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zürich
| | - Klaus Eyer
- Laboratory for Functional Immune Repertoire Analysis, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zürich; Department of Biomedicine, Aarhus University;
| | - Ines Lüchtefeld
- Laboratory for Functional Immune Repertoire Analysis, Institute of Pharmaceutical Sciences, Department of Chemistry and Applied Biosciences, ETH Zürich; Laboratory for Tumor and Stem Cell Dynamics, Institute of Molecular Health Sciences, Department of Biology, ETH Zürich;
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2
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Schlotheuber LJ, Lüchtefeld I, Eyer K. Antibodies, repertoires and microdevices in antibody discovery and characterization. Lab Chip 2024; 24:1207-1225. [PMID: 38165819 PMCID: PMC10898418 DOI: 10.1039/d3lc00887h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 12/01/2023] [Indexed: 01/04/2024]
Abstract
Therapeutic antibodies are paramount in treating a wide range of diseases, particularly in auto-immunity, inflammation and cancer, and novel antibody candidates recognizing a vast array of novel antigens are needed to expand the usefulness and applications of these powerful molecules. Microdevices play an essential role in this challenging endeavor at various stages since many general requirements of the overall process overlap nicely with the general advantages of microfluidics. Therefore, microfluidic devices are rapidly taking over various steps in the process of new candidate isolation, such as antibody characterization and discovery workflows. Such technologies can allow for vast improvements in time-lines and incorporate conservative antibody stability and characterization assays, but most prominently screenings and functional characterization within integrated workflows due to high throughput and standardized workflows. First, we aim to provide an overview of the challenges of developing new therapeutic candidates, their repertoires and requirements. Afterward, this review focuses on the discovery of antibodies using microfluidic systems, technological aspects of micro devices and small-scale antibody protein characterization and selection, as well as their integration and implementation into antibody discovery workflows. We close with future developments in microfluidic detection and antibody isolation principles and the field in general.
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Affiliation(s)
- Luca Johannes Schlotheuber
- ETH Laboratory for Functional Immune Repertoire Analysis, Institute of Pharmaceutical Sciences, D-CHAB, ETH Zürich, 8093 Zürich, Switzerland.
| | - Ines Lüchtefeld
- ETH Laboratory for Functional Immune Repertoire Analysis, Institute of Pharmaceutical Sciences, D-CHAB, ETH Zürich, 8093 Zürich, Switzerland.
- ETH Laboratory for Tumor and Stem Cell Dynamics, Institute of Molecular Health Sciences, D-BIOL, ETH Zürich, 8093 Zürich, Switzerland
| | - Klaus Eyer
- ETH Laboratory for Functional Immune Repertoire Analysis, Institute of Pharmaceutical Sciences, D-CHAB, ETH Zürich, 8093 Zürich, Switzerland.
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3
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Wahlsten A, Stracuzzi A, Lüchtefeld I, Restivo G, Lindenblatt N, Giampietro C, Ehret AE, Mazza E. Multiscale mechanical analysis of the elastic modulus of skin. Acta Biomater 2023; 170:155-168. [PMID: 37598792 DOI: 10.1016/j.actbio.2023.08.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 07/27/2023] [Accepted: 08/15/2023] [Indexed: 08/22/2023]
Abstract
The mechanical properties of the skin determine tissue function and regulate dermal cell behavior. Yet measuring these properties remains challenging, as evidenced by the large range of elastic moduli reported in the literature-from below one kPa to hundreds of MPa. Here, we reconcile these disparate results by dedicated experiments at both tissue and cellular length scales and by computational models considering the multiscale and multiphasic tissue structure. At the macroscopic tissue length scale, the collective behavior of the collagen fiber network under tension provides functional tissue stiffness, and its properties determine the corresponding elastic modulus (100-200 kPa). The compliant microscale environment (0.1-10 kPa), probed by atomic force microscopy, arises from the ground matrix without engaging the collagen fiber network. Our analysis indicates that indentation-based elasticity measurements, although probing tissue properties at the cell-relevant length scale, do not assess the deformation mechanisms activated by dermal cells when exerting traction forces on the extracellular matrix. Using dermal-equivalent collagen hydrogels, we demonstrate that indentation measurements of tissue stiffness do not correlate with the behavior of embedded dermal fibroblasts. These results provide a deeper understanding of tissue mechanics across length scales with important implications for skin mechanobiology and tissue engineering. STATEMENT OF SIGNIFICANCE: Measuring the mechanical properties of the skin is essential for understanding dermal cell mechanobiology and designing tissue-engineered skin substitutes. However, previous results reported for the elastic modulus of skin vary by six orders of magnitude. We show that two distinct deformation mechanisms, related to the tension-compression nonlinearity of the collagen fiber network, can explain the large variations in elastic moduli. Furthermore, we show that microscale indentation, which is frequently used to assess the stiffness perceived by cells, fails to engage the fiber network, and therefore cannot predict the behavior of dermal fibroblasts in stiffness-tunable fibrous hydrogels. This has important implications for how to measure and interpret the mechanical properties of soft tissues across length scales.
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Affiliation(s)
- Adam Wahlsten
- Institute for Mechanical Systems, Department of Mechanical and Process Engineering, ETH Zurich, Leonhardstrasse 21, Zurich 8092, Switzerland
| | - Alberto Stracuzzi
- Institute for Mechanical Systems, Department of Mechanical and Process Engineering, ETH Zurich, Leonhardstrasse 21, Zurich 8092, Switzerland; Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf 8600, Switzerland
| | - Ines Lüchtefeld
- Institute for Biomedical Engineering, Department of Information Technology and Electrical Engineering, ETH Zurich, Gloriastrasse 35, Zurich 8092, Switzerland
| | - Gaetana Restivo
- Department of Dermatology, University Hospital Zurich, Zurich 8091, Switzerland
| | - Nicole Lindenblatt
- Department of Plastic and Hand Surgery, University Hospital Zurich, Zurich 8091, Switzerland
| | - Costanza Giampietro
- Institute for Mechanical Systems, Department of Mechanical and Process Engineering, ETH Zurich, Leonhardstrasse 21, Zurich 8092, Switzerland; Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf 8600, Switzerland
| | - Alexander E Ehret
- Institute for Mechanical Systems, Department of Mechanical and Process Engineering, ETH Zurich, Leonhardstrasse 21, Zurich 8092, Switzerland; Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf 8600, Switzerland
| | - Edoardo Mazza
- Institute for Mechanical Systems, Department of Mechanical and Process Engineering, ETH Zurich, Leonhardstrasse 21, Zurich 8092, Switzerland; Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf 8600, Switzerland.
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4
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Ciccone G, Azevedo Gonzalez Oliva M, Antonovaite N, Lüchtefeld I, Salmeron-Sanchez M, Vassalli M. Experimental and Data Analysis Workflow for Soft Matter Nanoindentation. J Vis Exp 2022. [DOI: 10.3791/63401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
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5
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Demir I, Lüchtefeld I, Lemen C, Dague E, Guiraud P, Zambelli T, Formosa-Dague C. Probing the interactions between air bubbles and (bio)interfaces at the nanoscale using FluidFM technology. J Colloid Interface Sci 2021; 604:785-797. [PMID: 34303172 DOI: 10.1016/j.jcis.2021.07.036] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/23/2021] [Accepted: 07/06/2021] [Indexed: 10/20/2022]
Abstract
Understanding the molecular mechanisms underlying bubble-(bio)surfaces interactions is currently a challenge that if overcame, would allow to understand and control the various processes in which they are involved. Atomic force microscopy is a useful technique to measure such interactions, but it is limited by the large size and instability of the bubbles that it can use, attached either on cantilevers or on surfaces. We here present new developments where microsized and stable bubbles are produced using FluidFM technology, which combines AFM and microfluidics. The air bubbles produced were used to probe the interactions with hydrophobic samples, showing that bubbles in water behave like hydrophobic surfaces. They thus could be used to measure the hydrophobic properties of microorganisms' surfaces, but in this case the interactions are also influenced by electrostatic forces. Finally a strategy was developed to functionalize their surface, thereby modulating their interactions with microorganism interfaces. This new method provides a valuable tool to understand bubble-(bio)surfaces interactions but also to engineer them.
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Affiliation(s)
- Irem Demir
- TBI, Université de Toulouse, INSA, INRAE, CNRS, Toulouse, France; LAAS-CNRS, Université de Toulouse, CNRS, Toulouse, France
| | - Ines Lüchtefeld
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zurich, Zurich, Switzerland
| | - Claude Lemen
- TBI, Université de Toulouse, INSA, INRAE, CNRS, Toulouse, France
| | - Etienne Dague
- LAAS-CNRS, Université de Toulouse, CNRS, Toulouse, France; Fédération de Recherche Fermat, CNRS, Toulouse, France
| | - Pascal Guiraud
- TBI, Université de Toulouse, INSA, INRAE, CNRS, Toulouse, France; Fédération de Recherche Fermat, CNRS, Toulouse, France
| | - Tomaso Zambelli
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zurich, Zurich, Switzerland
| | - Cécile Formosa-Dague
- TBI, Université de Toulouse, INSA, INRAE, CNRS, Toulouse, France; Fédération de Recherche Fermat, CNRS, Toulouse, France.
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6
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Incaviglia I, Frutiger A, Blickenstorfer Y, Treindl F, Ammirati G, Lüchtefeld I, Dreier B, Plückthun A, Vörös J, Reichmuth AM. An Approach for the Real-Time Quantification of Cytosolic Protein-Protein Interactions in Living Cells. ACS Sens 2021; 6:1572-1582. [PMID: 33759497 DOI: 10.1021/acssensors.0c02480] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In recent years, cell-based assays have been frequently used in molecular interaction analysis. Cell-based assays complement traditional biochemical and biophysical methods, as they allow for molecular interaction analysis, mode of action studies, and even drug screening processes to be performed under physiologically relevant conditions. In most cellular assays, biomolecules are usually labeled to achieve specificity. In order to overcome some of the drawbacks associated with label-based assays, we have recently introduced "cell-based molography" as a biosensor for the analysis of specific molecular interactions involving native membrane receptors in living cells. Here, we expand this assay to cytosolic protein-protein interactions. First, we created a biomimetic membrane receptor by tethering one cytosolic interaction partner to the plasma membrane. The artificial construct is then coherently arranged into a two-dimensional pattern within the cytosol of living cells. Thanks to the molographic sensor, the specific interactions between the coherently arranged protein and its endogenous interaction partners become visible in real time without the use of a fluorescent label. This method turns out to be an important extension of cell-based molography because it expands the range of interactions that can be analyzed by molography to those in the cytosol of living cells.
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Affiliation(s)
- Ilaria Incaviglia
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Andreas Frutiger
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Yves Blickenstorfer
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Fridolin Treindl
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Giulia Ammirati
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Ines Lüchtefeld
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Birgit Dreier
- Department of Biochemistry, University of Zurich, 8057 Zurich, Switzerland
| | - Andreas Plückthun
- Department of Biochemistry, University of Zurich, 8057 Zurich, Switzerland
| | - Janos Vörös
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Andreas M Reichmuth
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zurich, 8092 Zurich, Switzerland
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7
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Lüchtefeld I, Bartolozzi A, Mejía Morales J, Dobre O, Basso M, Zambelli T, Vassalli M. Elasticity spectra as a tool to investigate actin cortex mechanics. J Nanobiotechnology 2020; 18:147. [PMID: 33081777 PMCID: PMC7576730 DOI: 10.1186/s12951-020-00706-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 10/09/2020] [Indexed: 12/24/2022] Open
Abstract
Background The mechanical properties of single living cells have proven to be a powerful marker of the cell physiological state. The use of nanoindentation-based single cell force spectroscopy provided a wealth of information on the elasticity of cells, which is still largely to be exploited. The simplest model to describe cell mechanics is to treat them as a homogeneous elastic material and describe it in terms of the Young’s modulus. Beside its simplicity, this approach proved to be extremely informative, allowing to assess the potential of this physical indicator towards high throughput phenotyping in diagnostic and prognostic applications. Results Here we propose an extension of this analysis to explicitly account for the properties of the actin cortex. We present a method, the Elasticity Spectra, to calculate the apparent stiffness of the cell as a function of the indentation depth and we suggest a simple phenomenological approach to measure the thickness and stiffness of the actin cortex, in addition to the standard Young’s modulus. Conclusions The Elasticity Spectra approach is tested and validated on a set of cells treated with cytoskeleton-affecting drugs, showing the potential to extend the current representation of cell mechanics, without introducing a detailed and complex description of the intracellular structure.![]()
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Affiliation(s)
- Ines Lüchtefeld
- Laboratory of Biosensors and Bioelectronics, ETH Zürich, Gloriastrasse 35, 8092, Zürich, Switzerland
| | - Alice Bartolozzi
- Dipartimento di Ingegneria dell'Informazione, Università degli studi di Firenze, Via di S. Marta 3, 50139, Firenze, Italy
| | - Julián Mejía Morales
- Institut de Physique de Nice, Université Côte d'Azur, 1361 Route des Lucioles, 06560, Valbonne, France.,Dipartimento di Medicina Sperimentale, Università degli studi di Genova, Via Leon Battista Alberti 2, 16132, Genova, Italy
| | - Oana Dobre
- James Watt School of Engineering, University of Glasgow, Oakfield avenue, Glasgow, G12 8LT, UK
| | - Michele Basso
- Dipartimento di Ingegneria dell'Informazione, Università degli studi di Firenze, Via di S. Marta 3, 50139, Firenze, Italy
| | - Tomaso Zambelli
- Laboratory of Biosensors and Bioelectronics, ETH Zürich, Gloriastrasse 35, 8092, Zürich, Switzerland
| | - Massimo Vassalli
- James Watt School of Engineering, University of Glasgow, Oakfield avenue, Glasgow, G12 8LT, UK.
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8
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Broguiere N, Lüchtefeld I, Trachsel L, Mazunin D, Rizzo R, Bode JW, Lutolf MP, Zenobi-Wong M. Morphogenesis Guided by 3D Patterning of Growth Factors in Biological Matrices. Adv Mater 2020; 32:e1908299. [PMID: 32390195 DOI: 10.1002/adma.201908299] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 03/26/2020] [Accepted: 03/26/2020] [Indexed: 05/23/2023]
Abstract
Three-dimensional (3D) control over the placement of bioactive cues is fundamental to understand cell guidance and develop engineered tissues. Two-photon patterning (2PP) provides such placement at micro- to millimeter scale, but nonspecific interactions between proteins and functionalized extracellular matrices (ECMs) restrict its use. Here, a 2PP system based on nonfouling hydrophilic photocages and Sortase A (SA)-based enzymatic coupling is presented, which offers unprecedented orthogonality and signal-to-noise ratio in both inert hydrogels and complex mammalian matrices. Improved photocaged peptide synthesis and protein functionalization protocols with broad applicability are introduced. Importantly, the method enables 2PP in a single step in the presence of fragile biomolecules and cells, and is compatible with time-controlled growth factor presentation. As a corollary, the guidance of axons through 3D-patterned nerve growth factor (NGF) within brain-mimetic ECMs is demonstrated. The approach allows for the interrogation of the role of complex signaling molecules in 3D matrices, thus helping to better understand biological guidance in tissue development and regeneration.
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Affiliation(s)
- Nicolas Broguiere
- Tissue Engineering and Biofabrication Laboratory, Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland
- Laboratory of Stem Cell Bioengineering, School of Life Sciences and School of Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Ines Lüchtefeld
- Tissue Engineering and Biofabrication Laboratory, Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland
| | - Lucca Trachsel
- Tissue Engineering and Biofabrication Laboratory, Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland
| | - Dmitry Mazunin
- Laboratorium für Organische Chemie, Department of Chemistry and Applied Biosciences, ETH Zürich, Zürich, Switzerland
| | - Riccardo Rizzo
- Tissue Engineering and Biofabrication Laboratory, Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland
| | - Jeffrey W Bode
- Laboratorium für Organische Chemie, Department of Chemistry and Applied Biosciences, ETH Zürich, Zürich, Switzerland
| | - Matthias P Lutolf
- Laboratory of Stem Cell Bioengineering, School of Life Sciences and School of Engineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Marcy Zenobi-Wong
- Tissue Engineering and Biofabrication Laboratory, Department of Health Sciences and Technology, ETH Zürich, Zürich, Switzerland
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9
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Aramesh M, Forró C, Dorwling-Carter L, Lüchtefeld I, Schlotter T, Ihle SJ, Shorubalko I, Hosseini V, Momotenko D, Zambelli T, Klotzsch E, Vörös J. Localized detection of ions and biomolecules with a force-controlled scanning nanopore microscope. Nat Nanotechnol 2019; 14:791-798. [PMID: 31308500 DOI: 10.1038/s41565-019-0493-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 06/03/2019] [Indexed: 06/10/2023]
Abstract
Proteins, nucleic acids and ions secreted from single cells are the key signalling factors that determine the interaction of cells with their environment and the neighbouring cells. It is possible to study individual ion channels by pipette clamping, but it is difficult to dynamically monitor the activity of ion channels and transporters across the cellular membrane. Here we show that a solid-state nanopore integrated in an atomic force microscope can be used for the stochastic sensing of secreted molecules and the activity of ion channels in arbitrary locations both inside and outside a cell. The translocation of biomolecules and ions through the nanopore is observed in real time in live cells. The versatile nature of this approach allows us to detect specific biomolecules under controlled mechanical confinement and to monitor the ion-channel activities of single cells. Moreover, the nanopore microscope was used to image the surface of the nuclear membrane via high-resolution scanning ion conductance measurements.
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Affiliation(s)
- Morteza Aramesh
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zürich, Zürich, Switzerland.
- Laboratory of Applied Mechanobiology, Department for Health Sciences and Technology, ETH Zürich, Zürich, Switzerland.
| | - Csaba Forró
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zürich, Zürich, Switzerland
| | - Livie Dorwling-Carter
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zürich, Zürich, Switzerland
| | - Ines Lüchtefeld
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zürich, Zürich, Switzerland
| | - Tilman Schlotter
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zürich, Zürich, Switzerland
| | - Stephan J Ihle
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zürich, Zürich, Switzerland
| | - Ivan Shorubalko
- Laboratory for Transport at Nanoscale Interfaces, Swiss Federal Laboratories for Materials Science and Technology (Empa), Dübendorf, Switzerland
| | - Vahid Hosseini
- Laboratory of Applied Mechanobiology, Department for Health Sciences and Technology, ETH Zürich, Zürich, Switzerland
| | - Dmitry Momotenko
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zürich, Zürich, Switzerland
| | - Tomaso Zambelli
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zürich, Zürich, Switzerland
| | - Enrico Klotzsch
- Laboratory of Applied Mechanobiology, Department for Health Sciences and Technology, ETH Zürich, Zürich, Switzerland
- Institute for Biology, Experimental Biophysics/ Mechanobiology, Humboldt University of Berlin, Berlin, Germany
| | - János Vörös
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zürich, Zürich, Switzerland.
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10
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Hwu S, Blickenstorfer Y, Tiefenauer RF, Gonnelli C, Schmidheini L, Lüchtefeld I, Hoogenberg BJ, Gisiger AB, Vörös J. Dark-Field Microwells toward High-Throughput Direct miRNA Sensing with Gold Nanoparticles. ACS Sens 2019; 4:1950-1956. [PMID: 31310098 DOI: 10.1021/acssensors.9b00946] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
MicroRNA (miRNA) is a class of short RNA that is emerging as an ideal biomarker, as its expression level has been found to correlate with different types of diseases including diabetes and cancer. The detection of miRNA is highly beneficial for early diagnostics and disease monitoring. However, miRNA sensing remains difficult because of its small size and low expression levels. Common techniques such as quantitative real-time polymerase chain reaction (qRT-PCR), in situ hybridization and Northern blotting have been developed to quantify miRNA in a given sample. Nevertheless, these methods face common challenges in point-of-care practice as they either require complicated sample handling and expensive equipment, or suffer from low sensitivity. Here we present a new tool based on dark-field microwells to overcome these challenges in miRNA sensing. This miniaturized device enables the readout of a gold nanoparticle assay without the need of a dark-field microscope. We demonstrate the feasibility of the dark-field microwells to detect miRNA in both buffer solution and cell lysate. The dark-field microwells allow affordable miRNA sensing at a high throughput which make them a promising tool for point-of-care diagnostics.
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Affiliation(s)
- Stephanie Hwu
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Yves Blickenstorfer
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Raphael F. Tiefenauer
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Claudio Gonnelli
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Lukas Schmidheini
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Ines Lüchtefeld
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Bas-Jan Hoogenberg
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - Andrea B. Gisiger
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zurich, 8092 Zurich, Switzerland
| | - János Vörös
- Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering, ETH Zurich, 8092 Zurich, Switzerland
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11
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Lüchtefeld I, Zambelli T, Vörös J. Investigation of Synaptic Vesicle Fusion Mechanisms with Novel Vesicular Force Microscopy. Biophys J 2018. [DOI: 10.1016/j.bpj.2017.11.3319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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12
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Gester K, Lüchtefeld I, Büsen M, Sonntag SJ, Linde T, Steinseifer U, Cattaneo G. In Vitro Evaluation of Intra-Aneurysmal, Flow-Diverter-Induced Thrombus Formation: A Feasibility Study. AJNR Am J Neuroradiol 2015; 37:490-6. [PMID: 26450536 DOI: 10.3174/ajnr.a4555] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 08/10/2015] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Intracranial aneurysm treatment by flow diverters aims at triggering intra-aneurysmal thrombosis. By combining in vitro blood experiments with particle imaging velocimetry measurements, we investigated the time-resolved thrombus formation triggered by flow diverters. MATERIALS AND METHODS Two test setups were built, 1 for particle imaging velocimetry and 1 for blood experiments, both generating the same pulsatile flow and including a silicone aneurysm model. Tests without flow diverters and with 2 different flow-diverter sizes (diameter: 4.5 and 4.0 mm) were performed. In the blood experiments, the intra-aneurysmal flow was monitored by using Doppler sonography. The experiments were stopped at 3 different changes of the spatial extent of the signal. RESULTS No thrombus was detected in the aneurysm model without the flow diverter. Otherwise, thrombi were observed in all aneurysm models with flow diverters. The thrombi grew from the proximal side of the aneurysm neck with fibrin threads connected to the flow diverter and extending across the aneurysm. The thrombus resulting from the 4.0-mm flow diverter grew along the aneurysm wall as a solid and organized thrombus, which correlates with the slower velocities near the wall detected by particle imaging velocimetry. The thrombus that evolved by using the 4.5-mm flow diverter showed no identifiable growing direction. The entire thrombus presumably resulted from stagnation of blood and correlates with the central vortex detected by particle imaging velocimetry. CONCLUSIONS We showed the feasibility of in vitro investigation of time-resolved thrombus formation in the presence of flow diverters.
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Affiliation(s)
- K Gester
- From the Department of Cardiovascular Engineering (K.G., I.L., M.B., S.J.S., T.L., U.S.), Institute of Applied Medical Engineering, Helmholtz Institute-RWTH Aachen University, Aachen, Germany
| | - I Lüchtefeld
- From the Department of Cardiovascular Engineering (K.G., I.L., M.B., S.J.S., T.L., U.S.), Institute of Applied Medical Engineering, Helmholtz Institute-RWTH Aachen University, Aachen, Germany
| | - M Büsen
- From the Department of Cardiovascular Engineering (K.G., I.L., M.B., S.J.S., T.L., U.S.), Institute of Applied Medical Engineering, Helmholtz Institute-RWTH Aachen University, Aachen, Germany
| | - S J Sonntag
- From the Department of Cardiovascular Engineering (K.G., I.L., M.B., S.J.S., T.L., U.S.), Institute of Applied Medical Engineering, Helmholtz Institute-RWTH Aachen University, Aachen, Germany
| | - T Linde
- From the Department of Cardiovascular Engineering (K.G., I.L., M.B., S.J.S., T.L., U.S.), Institute of Applied Medical Engineering, Helmholtz Institute-RWTH Aachen University, Aachen, Germany
| | - U Steinseifer
- From the Department of Cardiovascular Engineering (K.G., I.L., M.B., S.J.S., T.L., U.S.), Institute of Applied Medical Engineering, Helmholtz Institute-RWTH Aachen University, Aachen, Germany
| | - G Cattaneo
- Acandis GmbH & Co KG (G.C.), Pforzheim, Germany
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