1
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Chen S, Zhang S, Zhu R. Biophysical phenotyping of single-cell based on impedance and application for individualized precision medicine. Biosens Bioelectron 2024; 259:116410. [PMID: 38781697 DOI: 10.1016/j.bios.2024.116410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 05/03/2024] [Accepted: 05/19/2024] [Indexed: 05/25/2024]
Abstract
Single-cell biophysical characterization based on impedance measurement is an advantageous approach due to its label-free, high-efficiency, cost-effective and real-time capability. Biophysical phenotyping can yield timely and rich information on physiological and pathological state of cells for disease diagnosis, drug screening, precision medicine, etc. However, precise measurement on single-cell impedance is challenging, particularly hard to figure out the detailed biophysical parameters of single cell due to coupling and complexity of impedance model. Here, we propose an analytic determination method to decode single-cell electrophysiological parameters (including cell-substrate interface capacitance, cell membrane capacitance, cell membrane conductivity, and cytoplasm conductivity) from the impedances measured at optimized frequencies by using analytic solution rather than spectrum fitting. With this simple and fast analytic solution method, the physiological parameters of single cell in natural adhesion state can be accurately determined in real time. We validate this cell parameter determination method in monitoring the change of cell adhesion under hydraulic effects and exploring electrophysiological differences among MCF-7, HeLa, Huh7, and MDA-MB-231 cell lines. Particularly, we apply the approach to optimize tumor treating fields (TTFields) therapy, realizing individualized precision medicine. Our work provides an accurate and efficient approach for characterizing single-cell biophysical properties with real-time, in-situ, label-free, and less invasive advantages.
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Affiliation(s)
- Shengjie Chen
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, 100084, China
| | - Shengsen Zhang
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, 100084, China
| | - Rong Zhu
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, 100084, China.
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2
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Legerstee K, Sueters J, Abraham TE, Slotman JA, Kremers GJ, Hoogenboom JP, Houtsmuller AB. Correlative light and electron microscopy reveals fork-shaped structures at actin entry sites of focal adhesions. Biol Open 2022; 11:283176. [PMID: 36409550 PMCID: PMC9836080 DOI: 10.1242/bio.059417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 10/21/2022] [Indexed: 11/23/2022] Open
Abstract
Focal adhesions (FAs) are the main cellular structures to link the intracellular cytoskeleton to the extracellular matrix. FAs mediate cell adhesion, are important for cell migration and are involved in many (patho)-physiological processes. Here we examined FAs and their associated actin fibres using correlative fluorescence and scanning electron microscopy (SEM). We used fluorescence images of cells expressing paxillin-GFP to define the boundaries of FA complexes in SEM images, without using SEM contrast enhancing stains. We observed that SEM contrast was increased around the actin fibre entry site in 98% of FAs, indicating increases in protein density and possibly also phosphorylation levels in this area. In nearly three quarters of the FAs, these nanostructures had a fork shape, with the actin forming the stem and the high-contrast FA areas the fork. In conclusion, the combination of fluorescent and electron microscopy allowed accurate localisation of a highly abundant, novel fork structure at the FA-actin interface.
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Affiliation(s)
- Karin Legerstee
- Erasmus Medical Centre Rotterdam, Department of Pathology, Optical Imaging Centre, 3000 CA, Rotterdam, The Netherlands
| | - Jason Sueters
- Delft University of Technology, Department of Imaging Physics, 2628 CD, Delft, The Netherlands
| | - Tsion E. Abraham
- Erasmus Medical Centre Rotterdam, Department of Pathology, Optical Imaging Centre, 3000 CA, Rotterdam, The Netherlands
| | - Johan A. Slotman
- Erasmus Medical Centre Rotterdam, Department of Pathology, Optical Imaging Centre, 3000 CA, Rotterdam, The Netherlands
| | - Gert-Jan Kremers
- Erasmus Medical Centre Rotterdam, Department of Pathology, Optical Imaging Centre, 3000 CA, Rotterdam, The Netherlands
| | - Jacob P. Hoogenboom
- Delft University of Technology, Department of Imaging Physics, 2628 CD, Delft, The Netherlands
| | - Adriaan B. Houtsmuller
- Erasmus Medical Centre Rotterdam, Department of Pathology, Optical Imaging Centre, 3000 CA, Rotterdam, The Netherlands,Author for correspondence ()
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3
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Slepička P, Rimpelová S, Svobodová Pavlíčková V, Slepičková Kasálková N, Hurtuková K, Fajstavr D, Švorčík V. Mammalian Cell Interaction with Periodic Surface Nanostructures. Int J Mol Sci 2022; 23:ijms23094676. [PMID: 35563068 PMCID: PMC9100987 DOI: 10.3390/ijms23094676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 04/17/2022] [Accepted: 04/20/2022] [Indexed: 12/04/2022] Open
Abstract
Here, we report on the nanopatterning of different aromatic polymer substrates achieved by KrF excimer laser treatment. The conditions for the construction of the laser-induced periodic surface structures, the so-called LIPSS pattern, were established by optimized laser fluence and a number of pulses. The polymer substrates were polyethylene naphthalate (PEN), polyethersulfone (PES), and polystyrene (PS), which were chosen since they are thermally, chemically, and mechanically resistant polymers with high absorption coefficients at the excimer laser wavelength. The surface morphology of the treated substrates was investigated by atomic force microscopy and scanning electron microscopy, and the roughness and effective surface area on the modified samples were determined. Elemental concentration was characterized by energy-dispersive (EDX) analysis, surface chemistry was determined with X-ray photoelectron spectroscopy (XPS). The samples with the formation of LIPSS induced by 10 mJ·cm−2 with 1000, 3000, and 6000 pulses were used for subsequent in vitro cytocompatibility tests using human cells from osteosarcoma (U-2 OS). The LIPSS pattern and its ability of significant cell guidance were confirmed for some of the studied samples. Cell morphology, adhesion, and proliferation were evaluated. The results strongly contribute to the development of novel applications using nanopatterned polymers, e.g., in tissue engineering, cell analysis or in combination with metallization for sensor construction.
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Affiliation(s)
- Petr Slepička
- Department of Solid State Engineering, University of Chemistry and Technology Prague, 166 28 Prague, Czech Republic; (N.S.K.); (K.H.); (D.F.); (V.Š.)
- Correspondence: (P.S.); (S.R.)
| | - Silvie Rimpelová
- Department of Biochemistry and Microbiology, University of Chemistry and Technology Prague, 166 28 Prague, Czech Republic;
- Correspondence: (P.S.); (S.R.)
| | - Vladimíra Svobodová Pavlíčková
- Department of Biochemistry and Microbiology, University of Chemistry and Technology Prague, 166 28 Prague, Czech Republic;
| | - Nikola Slepičková Kasálková
- Department of Solid State Engineering, University of Chemistry and Technology Prague, 166 28 Prague, Czech Republic; (N.S.K.); (K.H.); (D.F.); (V.Š.)
| | - Klaudia Hurtuková
- Department of Solid State Engineering, University of Chemistry and Technology Prague, 166 28 Prague, Czech Republic; (N.S.K.); (K.H.); (D.F.); (V.Š.)
| | - Dominik Fajstavr
- Department of Solid State Engineering, University of Chemistry and Technology Prague, 166 28 Prague, Czech Republic; (N.S.K.); (K.H.); (D.F.); (V.Š.)
| | - Václav Švorčík
- Department of Solid State Engineering, University of Chemistry and Technology Prague, 166 28 Prague, Czech Republic; (N.S.K.); (K.H.); (D.F.); (V.Š.)
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4
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Emmert M, Somorowsky F, Ebert J, Görick D, Heyn A, Rosenberger E, Wahl M, Heinrich D. Modulation of Mammalian Cell Behavior by Nanoporous Glass. Adv Biol (Weinh) 2021; 5:e2000570. [PMID: 33960740 DOI: 10.1002/adbi.202000570] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 03/31/2021] [Indexed: 11/08/2022]
Abstract
The introduction of novel bioactive materials to manipulate living cell behavior is a crucial topic for biomedical research and tissue engineering. Biomaterials or surface patterns that boost specific cell functions can enable innovative new products in cell culture and diagnostics. This study investigates the influence of the intrinsically nano-patterned surface of nanoporous glass membranes on the behavior of mammalian cells. Three different cell lines and primary human mesenchymal stem cells (hMSCs) proliferate readily on nanoporous glass membranes with mean pore sizes between 10 and 124 nm. In both proliferation and mRNA expression experiments, L929 fibroblasts show a distinct trend toward mean pore sizes >80 nm. For primary hMSCs, excellent proliferation is observed on all nanoporous surfaces. hMSCs on samples with 17 nm pore size display increased expression of COL10, COL2A1, and SOX9, especially during the first two weeks of culture. In the upside down culture, SK-MEL-28 cells on nanoporous glass resist the gravitational force and proliferate well in contrast to cells on flat references. The effect of paclitaxel treatment of MDA-MB-321 breast cancer cells is already visible after 48 h on nanoporous membranes and strongly pronounced in comparison to reference samples, underlining the material's potential for functional drug screening.
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Affiliation(s)
- Martin Emmert
- Fraunhofer Institute for Silicate Research ISC, Neunerplatz 2, 97082, Würzburg, Germany.,Julius-Maximilians-Universität Würzburg, Chemical Technology of Material Synthesis, Röntgenring 11, 97070, Würzburg, Germany
| | - Ferdinand Somorowsky
- Fraunhofer Institute for Silicate Research ISC, Neunerplatz 2, 97082, Würzburg, Germany
| | - Jutta Ebert
- Fraunhofer Institute for Silicate Research ISC, Neunerplatz 2, 97082, Würzburg, Germany
| | - Dominik Görick
- Fraunhofer Institute for Silicate Research ISC, Neunerplatz 2, 97082, Würzburg, Germany
| | - Andreas Heyn
- Julius-Maximilians-Universität Würzburg, Chemical Technology of Material Synthesis, Röntgenring 11, 97070, Würzburg, Germany
| | - Eva Rosenberger
- Fraunhofer Institute for Silicate Research ISC, Neunerplatz 2, 97082, Würzburg, Germany
| | - Moritz Wahl
- Julius-Maximilians-Universität Würzburg, Chemical Technology of Material Synthesis, Röntgenring 11, 97070, Würzburg, Germany
| | - Doris Heinrich
- Fraunhofer Institute for Silicate Research ISC, Neunerplatz 2, 97082, Würzburg, Germany.,Leiden University, LION Leiden Institute of Physics, Niels Bohrweg 2, Leiden, 2333 CA, The Netherlands
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5
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Goto T, Kasai N, Filip R, Sumitomo K, Nakashima H. Observation of intracellular protein localization area in a single neuron using gold nanoparticles with a scanning electron microscope. Micron 2019; 126:102740. [DOI: 10.1016/j.micron.2019.102740] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 08/26/2019] [Accepted: 08/26/2019] [Indexed: 11/28/2022]
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6
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Henn I, Atkins A, Markus A, Shpun G, Barad H, Farah N, Mandel Y. SEM/FIB Imaging for Studying Neural Interfaces. Dev Neurobiol 2019; 80:305-315. [DOI: 10.1002/dneu.22707] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 05/11/2019] [Accepted: 06/15/2019] [Indexed: 11/12/2022]
Affiliation(s)
- Itai Henn
- Mina and Everard Goodman Faculty of Life Sciences Bar‐Ilan University Ramat Gan Israel
- Bar‐Ilan Institute for Nanotechnology and Advanced Materials (BINA) Bar‐Ilan University Ramat Gan Israel
| | - Ayelet Atkins
- Mina and Everard Goodman Faculty of Life Sciences Bar‐Ilan University Ramat Gan Israel
- Bar‐Ilan Institute for Nanotechnology and Advanced Materials (BINA) Bar‐Ilan University Ramat Gan Israel
| | - Amos Markus
- Mina and Everard Goodman Faculty of Life Sciences Bar‐Ilan University Ramat Gan Israel
| | - Gal Shpun
- Mina and Everard Goodman Faculty of Life Sciences Bar‐Ilan University Ramat Gan Israel
- Bar‐Ilan Institute for Nanotechnology and Advanced Materials (BINA) Bar‐Ilan University Ramat Gan Israel
| | - Hannah‐Noa Barad
- Bar‐Ilan Institute for Nanotechnology and Advanced Materials (BINA) Bar‐Ilan University Ramat Gan Israel
- Department of Chemistry, Bar‐Ilan Institute for Nanotechnology and Advanced Materials (BINA) Bar‐Ilan University Ramat Gan Israel
| | - Nairouz Farah
- Mina and Everard Goodman Faculty of Life Sciences Bar‐Ilan University Ramat Gan Israel
- Faculty of Life Science, School of Optometry and Vision Science Bar‐Ilan University Ramat Gan Israel
| | - Yossi Mandel
- Mina and Everard Goodman Faculty of Life Sciences Bar‐Ilan University Ramat Gan Israel
- Bar‐Ilan Institute for Nanotechnology and Advanced Materials (BINA) Bar‐Ilan University Ramat Gan Israel
- Faculty of Life Science, School of Optometry and Vision Science Bar‐Ilan University Ramat Gan Israel
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7
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McGuire AF, Santoro F, Cui B. Interfacing Cells with Vertical Nanoscale Devices: Applications and Characterization. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2018; 11:101-126. [PMID: 29570360 PMCID: PMC6530470 DOI: 10.1146/annurev-anchem-061417-125705] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Measurements of the intracellular state of mammalian cells often require probes or molecules to breach the tightly regulated cell membrane. Mammalian cells have been shown to grow well on vertical nanoscale structures in vitro, going out of their way to reach and tightly wrap the structures. A great deal of research has taken advantage of this interaction to bring probes close to the interface or deliver molecules with increased efficiency or ease. In turn, techniques have been developed to characterize this interface. Here, we endeavor to survey this research with an emphasis on the interface as driven by cellular mechanisms.
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Affiliation(s)
- Allister F McGuire
- Department of Chemistry, Stanford University, Stanford, California 94305, USA;
| | - Francesca Santoro
- Department of Chemistry, Stanford University, Stanford, California 94305, USA;
- Center for Advanced Biomaterials for Healthcare, Istituto Italiano di Tecnologia, 80125 Naples, Italy;
| | - Bianxiao Cui
- Department of Chemistry, Stanford University, Stanford, California 94305, USA;
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8
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Gui N, Xu W, Abraham AN, Myers DE, Mayes ELH, Xia K, Shukla R, Qian M. A comparative study of the effect of submicron porous and smooth ultrafine-grained Ti-20Mo surfaces on osteoblast responses. J Biomed Mater Res A 2018; 106:2020-2033. [PMID: 29569836 DOI: 10.1002/jbm.a.36402] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 02/20/2018] [Accepted: 03/15/2018] [Indexed: 11/08/2022]
Abstract
The surface of an orthopaedic implant plays a crucial role in determining the adsorption of proteins and cell functions. A detailed comparative study has been made of the in vitro osteoblast responses to coarse-grained (grain size: 500 μm), ultrafine-grained (grain size: 100 nm), coarse-porous (pore size: 350 nm), and fine-porous (pore size: 155 nm) surfaces of Ti-20Mo alloy. The purpose was to provide essential experimental data for future design of orthopaedic titanium implants for rapid osseointegration. Systematic original experimental data was produced for each type of surfaces in terms of surface wettability, cell morphology, adhesion, growth, and differentiation. Microscopic evidence was collected to reveal the detailed interplay between each characteristic surface with proteins or cells. Various new observations were discussed and compared with literature data. It was concluded that the coarse-porous surfaces offered the optimum topographical environment for osteoblasts and that the combination of ultrafine grains and considerable grain boundary areas is not an effective way to enhance cell growth and osteogenic capacity. Moreover, pore features (size and depth) have a greater effect than smooth surfaces on cell growth and osteogenic capacity. It proves that cells can discern the difference in pore size in the range of 100-350 nm. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2020-2033, 2018.
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Affiliation(s)
- Na Gui
- Centre for Additive Manufacturing, School of Engineering, RMIT University, Melbourne, Victoria, 3000, Australia
| | - Wei Xu
- Centre for Additive Manufacturing, School of Engineering, RMIT University, Melbourne, Victoria, 3000, Australia.,School of Engineering, Macquarie University, Sydney, New South Wales, 2109, Australia.,Department of Mechanical Engineering, University of Melbourne, Victoria, 3010, Australia
| | - Amanda N Abraham
- Nanobiotechnology Research Laboratory and Centre for Advanced Materials & Industrial Chemistry, School of Science, RMIT University, Melbourne, Victoria 3001, Australia
| | - Damian E Myers
- Australian Institute for Musculoskeletal Science, Department of Medicine, Western Health, University of Melbourne, Melbourne, Victoria, 3010, Australia.,College of Health and Biomedicine, Victoria University; Western Centre for Health and Research Education, Sunshine Hospital, Victoria, 3021, Australia
| | - Edwin L H Mayes
- RMIT Microscopy and Microanalysis Facility (RMMF), GPO Box 2467V, Melbourne, Victoria, 3000, Australia
| | - Kenong Xia
- Department of Mechanical Engineering, University of Melbourne, Victoria, 3010, Australia
| | - Ravi Shukla
- Nanobiotechnology Research Laboratory and Centre for Advanced Materials & Industrial Chemistry, School of Science, RMIT University, Melbourne, Victoria 3001, Australia
| | - Ma Qian
- Centre for Additive Manufacturing, School of Engineering, RMIT University, Melbourne, Victoria, 3000, Australia
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9
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Diez-Escudero A, Espanol M, Montufar EB, Di Pompo G, Ciapetti G, Baldini N, Ginebra MP. Focus Ion Beam/Scanning Electron Microscopy Characterization of Osteoclastic Resorption of Calcium Phosphate Substrates. Tissue Eng Part C Methods 2017; 23:118-124. [DOI: 10.1089/ten.tec.2016.0361] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Affiliation(s)
- Anna Diez-Escudero
- Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgical Engineering, Technical University of Catalonia (UPC), Barcelona, Spain
- Center for Research in NanoEngineering (CRnE), UPC, Barcelona, Spain
| | - Montserrat Espanol
- Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgical Engineering, Technical University of Catalonia (UPC), Barcelona, Spain
- Center for Research in NanoEngineering (CRnE), UPC, Barcelona, Spain
| | - Edgar B. Montufar
- Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgical Engineering, Technical University of Catalonia (UPC), Barcelona, Spain
- Center for Research in NanoEngineering (CRnE), UPC, Barcelona, Spain
| | - Gemma Di Pompo
- Orthopaedic Pathophysiology and Regenerative Medicine Unit, IstitutoOrtopedico Rizzoli, Bologna, Italy
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Gabriela Ciapetti
- Orthopaedic Pathophysiology and Regenerative Medicine Unit, IstitutoOrtopedico Rizzoli, Bologna, Italy
| | - Nicola Baldini
- Orthopaedic Pathophysiology and Regenerative Medicine Unit, IstitutoOrtopedico Rizzoli, Bologna, Italy
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Maria-Pau Ginebra
- Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgical Engineering, Technical University of Catalonia (UPC), Barcelona, Spain
- Center for Research in NanoEngineering (CRnE), UPC, Barcelona, Spain
- Institute for Bioengineering of Catalonia, Barcelona, Spain
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10
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Improved Measurement of Elastic Properties of Cells by Micropipette Aspiration and Its Application to Lymphocytes. Ann Biomed Eng 2017; 45:1375-1385. [DOI: 10.1007/s10439-017-1795-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 01/10/2017] [Indexed: 10/24/2022]
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11
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Belu A, Schnitker J, Bertazzo S, Neumann E, Mayer D, Offenhäusser A, Santoro F. Ultra-thin resin embedding method for scanning electron microscopy of individual cells on high and low aspect ratio 3D nanostructures. J Microsc 2016; 263:78-86. [PMID: 26820619 DOI: 10.1111/jmi.12378] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Accepted: 12/09/2015] [Indexed: 01/18/2023]
Abstract
The preparation of biological cells for either scanning or transmission electron microscopy requires a complex process of fixation, dehydration and drying. Critical point drying is commonly used for samples investigated with a scanning electron beam, whereas resin-infiltration is typically used for transmission electron microscopy. Critical point drying may cause cracks at the cellular surface and a sponge-like morphology of nondistinguishable intracellular compartments. Resin-infiltrated biological samples result in a solid block of resin, which can be further processed by mechanical sectioning, however that does not allow a top view examination of small cell-cell and cell-surface contacts. Here, we propose a method for removing resin excess on biological samples before effective polymerization. In this way the cells result to be embedded in an ultra-thin layer of epoxy resin. This novel method highlights in contrast to standard methods the imaging of individual cells not only on nanostructured planar surfaces but also on topologically challenging substrates with high aspect ratio three-dimensional features by scanning electron microscopy.
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Affiliation(s)
- A Belu
- Institute of Complex Systems and Peter Grünberg Institute (ICS-8/PGI-8) - Bioelectronics, Forschungszentrum Jülich GmbH, Jülich, and JARA-Fundamentals of Future Information Technology, Germany
| | - J Schnitker
- Institute of Complex Systems and Peter Grünberg Institute (ICS-8/PGI-8) - Bioelectronics, Forschungszentrum Jülich GmbH, Jülich, and JARA-Fundamentals of Future Information Technology, Germany
| | - S Bertazzo
- Department of Medical Physics & Biomedical Engineering, University College London, Malet Place Engineering Building, London WC1E 6BT, U.K
| | - E Neumann
- Institute of Complex Systems and Peter Grünberg Institute (ICS-8/PGI-8) - Bioelectronics, Forschungszentrum Jülich GmbH, Jülich, and JARA-Fundamentals of Future Information Technology, Germany
| | - D Mayer
- Institute of Complex Systems and Peter Grünberg Institute (ICS-8/PGI-8) - Bioelectronics, Forschungszentrum Jülich GmbH, Jülich, and JARA-Fundamentals of Future Information Technology, Germany
| | - A Offenhäusser
- Institute of Complex Systems and Peter Grünberg Institute (ICS-8/PGI-8) - Bioelectronics, Forschungszentrum Jülich GmbH, Jülich, and JARA-Fundamentals of Future Information Technology, Germany
| | - F Santoro
- Institute of Complex Systems and Peter Grünberg Institute (ICS-8/PGI-8) - Bioelectronics, Forschungszentrum Jülich GmbH, Jülich, and JARA-Fundamentals of Future Information Technology, Germany
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12
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Cryo-planing of frozen-hydrated samples using cryo triple ion gun milling (CryoTIGM™). J Struct Biol 2015; 192:569-579. [PMID: 26549007 DOI: 10.1016/j.jsb.2015.11.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 11/04/2015] [Accepted: 11/05/2015] [Indexed: 11/23/2022]
Abstract
Cryo-SEM is a high throughput technique for imaging biological ultrastructure in its most pristine state, i.e. without chemical fixation, embedding, or drying. Freeze fracture is routinely used to prepare internal surfaces for cryo-SEM imaging. However, the propagation of the fracture plane is highly dependent on sample properties, and the resulting surface frequently shows substantial topography, which can complicate image analysis and interpretation. We have developed a broad ion beam milling technique, called cryogenic triple ion gun milling (CryoTIGM™ ['krī-ə-,tīm]), for cryo-planing frozen-hydrated biological specimens. Comparing sample preparation by CryoTIGM™ and freeze fracture in three model systems, Baker's yeast, mouse liver tissue, and whole sea urchin embryos, we find that CryoTIGM™ yields very large (∼700,000 μm(2)) and smooth sections that present ultrastructural details at similar or better quality than freeze-fractured samples. A particular strength of CryoTIGM™ is the ability to section samples with hard-soft contrast such as brittle calcite (CaCO3) spicules in the sea urchin embryo.
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13
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Adineh VR, Liu B, Rajan R, Yan W, Fu J. Multidimensional characterisation of biomechanical structures by combining Atomic Force Microscopy and Focused Ion Beam: A study of the rat whisker. Acta Biomater 2015; 21:132-41. [PMID: 25839121 DOI: 10.1016/j.actbio.2015.03.028] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 03/23/2015] [Accepted: 03/23/2015] [Indexed: 01/13/2023]
Abstract
Understanding the heterogeneity of biological structures, particularly at the micro/nano scale can offer insights valuable for multidisciplinary research in tissue engineering and biomimicry designs. Here we propose to combine nanocharacterisation tools, particularly Focused Ion Beam (FIB) and Atomic Force Microscopy (AFM) for three dimensional mapping of mechanical modulus and chemical signatures. The prototype platform is applied to image and investigate the fundamental mechanics of the rat face whiskers, a high-acuity sensor used to gain detailed information about the world. Grazing angle FIB milling was first applied to expose the interior cross section of the rat whisker sample, followed by a "lift-out" method to retrieve and position the target sample for further analyses. AFM force spectroscopy measurements revealed a non-uniform pattern of elastic modulus across the cross section, with a range from 0.8GPa to 13.5GPa. The highest elastic modulus was found at the outer cuticle region of the whisker, and values gradually decreased towards the interior cortex and medulla regions. Elemental mapping with EDS confirmed that the interior of the rat whisker is dominated by C, O, N, S, Cl and K, with a significant change of elemental distribution close to the exterior cuticle region. Based on these data, a novel comprehensive three dimensional (3D) elastic modulus model was constructed, and stress distributions under realistic conditions were investigated with Finite Element Analysis (FEA). The simulations could well account for the passive whisker deflections, with calculated resonant frequency as well as force-deflection for the whiskers being in good agreement with reported experimental data. Limitations and further applications are discussed for the proposed FIB/AFM approach, which holds good promise as a unique platform to gain insights on various heterogeneous biomaterials and biomechanical systems.
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Affiliation(s)
- Vahid Reza Adineh
- Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia
| | - Boyin Liu
- Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia
| | - Ramesh Rajan
- Department of Physiology, Monash University, Clayton, VIC 3800, Australia
| | - Wenyi Yan
- Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia
| | - Jing Fu
- Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia.
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14
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Bakhsh TA, Sadr A, Mandurah MM, Shimada Y, Zakaria O, Tagami J. In situ characterization of resin-dentin interfaces using conventional vs. cryofocused ion-beam milling. Dent Mater 2015; 31:833-44. [PMID: 25986333 DOI: 10.1016/j.dental.2015.04.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 10/11/2014] [Accepted: 04/16/2015] [Indexed: 11/19/2022]
Abstract
OBJECTIVE The introduction of focused ion beam (FIB) milling has facilitated preparation of hard tissue samples for transmission electron microscope (TEM). However, this technique generates high temperature that may alter or damage morphological features in biological tissue. Therefore, the aim of this study was to determine the effects of cryogenic cooling on the morphological features of dentin interfaces with dental restorative materials in samples prepared by FIB for TEM examination. METHODS After preparation of a cylindrical-shaped cavities in extracted, non-carious premolar teeth, the specimens were restored with dental adhesive/composite and categorized into two restorative materials groups; (PB) a combination of Clearfil Protect Bond (Kuraray Noritake Dental, Japan)/Estelite Sigma Quick composite (Tokuyama Dental, Japan), and (SB) Filtek Silorane restorative system (3M ESPE, USA). The specimens were subjected to interfacial cross-sectioning, followed by observation and area selection using confocal laser microscopy. Later, ultrathin sections were prepared using FIB with cryogenic cooling (PB-C) and (SB-C), or without cooling (PB-NC) and (SB-NC) that all were examined under TEM. RESULTS Resulting TEM images of the ultra-morphological features at the resin-dentin nano-interaction zone were improved when FIB preparation was conducted in the cryogenic condition and no sign of artifacts were detected. SIGNIFICANCE Conducting ion beam milling with cryogenic cooling was advantageous in minimizing the elevation in specimen temperature. This led to preservation of dentin microstructures that revealed additional information about substrates that are necessary for advanced characterization of tooth-biomaterial interactions.
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Affiliation(s)
- Turki A Bakhsh
- Operative Dentistry Department, Faculty of Dentistry, King Abdulaziz University, P.O. Box 80209, Jeddah 215-89, Saudi Arabia.
| | - Alireza Sadr
- Cariology and Operative Dentistry Department, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan; University of Washington School of Dentistry, 1959 NE Pacific St, Seattle, WA 98195, United States
| | - Mona M Mandurah
- Cariology and Operative Dentistry Department, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
| | - Yasushi Shimada
- Cariology and Operative Dentistry Department, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
| | - Osama Zakaria
- Oral Surgery, Faculty of Dentistry, Pharos University, 10 Elbostan St. Elmandara, Alexandria, Egypt
| | - Junji Tagami
- Cariology and Operative Dentistry Department, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
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15
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Lee MH, Son JS, Kim KH, Kwon TY. Improved Resin-Zirconia Bonding by Room Temperature Hydrofluoric Acid Etching. MATERIALS 2015; 8:850-866. [PMID: 28787975 PMCID: PMC5455444 DOI: 10.3390/ma8030850] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Revised: 02/12/2015] [Accepted: 02/15/2015] [Indexed: 11/27/2022]
Abstract
This in vitro study was conducted to evaluate the shear bond strength of “non-self-adhesive” resin to dental zirconia etched with hydrofluoric acid (HF) at room temperature and to compare it to that of air-abraded zirconia. Sintered zirconia plates were air-abraded (control) or etched with 10%, 20%, or 30% HF for either 5 or 30 min. After cleaning, the surfaces were characterized using various analytical techniques. Three resin cylinders (Duo-Link) were bonded to each treated plate. All bonded specimens were stored in water at 37 °C for 24 h, and then half of them were additionally thermocycled 5000 times prior to the shear bond-strength tests (n = 12). The formation of micro- and nano-porosities on the etched surfaces increased with increasing concentration and application time of the HF solution. The surface wettability of zirconia also increased with increasing surface roughness. Higher concentrations and longer application times of the HF solution produced higher bond-strength values. Infiltration of the resin into the micro- and nano-porosities was observed by scanning electron microscopy. This in vitro study suggests that HF slowly etches zirconia ceramic surfaces at room temperature, thereby improving the resin–zirconia bond strength by the formation of retentive sites.
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Affiliation(s)
- Mun-Hwan Lee
- Department of Medical & Biological Engineering, Graduate School, Kyungpook National University, 2-188-1 Samduk-dong, Jung-gu, Daegu 700-412, Korea.
| | - Jun Sik Son
- Korea Textile Development Institute, 1083 Jungri-dong, Seo-gu, Daegu 703-712, Korea.
| | - Kyo-Han Kim
- Department of Dental Biomaterials, School of Dentistry, Kyungpook National University, 2-188-1 Samduk-dong, Jung-gu, Daegu 700-412, Korea.
| | - Tae-Yub Kwon
- Department of Dental Biomaterials, School of Dentistry, Kyungpook National University, 2-188-1 Samduk-dong, Jung-gu, Daegu 700-412, Korea.
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16
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Hamano T, Dwiranti A, Kaneyoshi K, Fukuda S, Kometani R, Nakao M, Takata H, Uchiyama S, Ohmido N, Fukui K. Chromosome interior observation by focused ion beam/scanning electron microscopy (FIB/SEM) using ionic liquid technique. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2014; 20:1340-7. [PMID: 25010743 DOI: 10.1017/s143192761401280x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Attempts to elucidate chromosome structure have long remained elusive. Electron microscopy is useful for chromosome structure research because of its high resolution and magnification. However, biological samples such as chromosomes need to be subjected to various preparation steps, including dehydration, drying, and metal/carbon coating, which may induce shrinkage and artifacts. The ionic liquid technique has recently been developed and it enables sample preparation without dehydration, drying, or coating, providing a sample that is closer to the native condition. Concurrently, focused ion beam/scanning electron microscopy (FIB/SEM) has been developed, allowing the investigation and direct analysis of chromosome interiors. In this study, we investigated chromosome interiors by FIB/SEM using plant and human chromosomes prepared by the ionic liquid technique. As a result, two types of chromosomes, with and without cavities, were visualized, both for barley and human chromosomes prepared by critical point drying. However, chromosome interiors were revealed only as a solid structure, lacking cavities, when prepared by the ionic liquid technique. Our results suggest that the existence and size of cavities depend on the preparation procedures. We conclude that combination of the ionic liquid technique and FIB/SEM is a powerful tool for chromosome study.
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Affiliation(s)
- Tohru Hamano
- 1Laboratory of Dynamic Cell Biology,Department of Biotechnology,Graduate School of Engineering,Osaka University,Yamadaoka,Suita,Osaka 565-0871,Japan
| | - Astari Dwiranti
- 1Laboratory of Dynamic Cell Biology,Department of Biotechnology,Graduate School of Engineering,Osaka University,Yamadaoka,Suita,Osaka 565-0871,Japan
| | - Kohei Kaneyoshi
- 1Laboratory of Dynamic Cell Biology,Department of Biotechnology,Graduate School of Engineering,Osaka University,Yamadaoka,Suita,Osaka 565-0871,Japan
| | - Shota Fukuda
- 1Laboratory of Dynamic Cell Biology,Department of Biotechnology,Graduate School of Engineering,Osaka University,Yamadaoka,Suita,Osaka 565-0871,Japan
| | - Reo Kometani
- 2Laboratory of Nano Mechanics,Department of Mechanical Engineering,Graduate School of Engineering,The University of Tokyo,Hongo,Bunkyo,Tokyo 113-8685,Japan
| | - Masayuki Nakao
- 3Department of Engineering Synthesis,Graduate School of Engineering,The University of Tokyo,Hongo,Bunkyo,Tokyo 113-8685,Japan
| | - Hideaki Takata
- 1Laboratory of Dynamic Cell Biology,Department of Biotechnology,Graduate School of Engineering,Osaka University,Yamadaoka,Suita,Osaka 565-0871,Japan
| | - Susumu Uchiyama
- 1Laboratory of Dynamic Cell Biology,Department of Biotechnology,Graduate School of Engineering,Osaka University,Yamadaoka,Suita,Osaka 565-0871,Japan
| | - Nobuko Ohmido
- 4Department of Human Environmental Science,Division of Living Environment,Graduate School of Human Development and Environment,Kobe University,Tsurukabuto,Nada,Kobe 657-8501,Japan
| | - Kiichi Fukui
- 1Laboratory of Dynamic Cell Biology,Department of Biotechnology,Graduate School of Engineering,Osaka University,Yamadaoka,Suita,Osaka 565-0871,Japan
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17
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Lai M, Hermann CD, Cheng A, Olivares-Navarrete R, Gittens RA, Bird MM, Walker M, Cai Y, Cai K, Sandhage KH, Schwartz Z, Boyan BD. Role of α2β1 integrins in mediating cell shape on microtextured titanium surfaces. J Biomed Mater Res A 2014; 103:564-73. [PMID: 24733736 DOI: 10.1002/jbm.a.35185] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 04/02/2014] [Indexed: 12/21/2022]
Abstract
Surface microroughness plays an important role in determining osteoblast behavior on titanium. Previous studies have shown that osteoblast differentiation on microtextured titanium substrates is dependent on alpha-2 beta-1 (α2β1) integrin signaling. This study used focused ion beam milling and scanning electron microscopy, combined with three-dimensional image reconstruction, to investigate early interactions of individual cells with their substrate and the role of integrin α2β1 in determining cell shape. MG63 osteoblast-like cells on sand blasted/acid etched (SLA) Ti surfaces after 3 days of culturing indicated decreased cell number, increased cell differentiation, and increased expression of mRNA levels for α1, α2, αV, and β1 integrin subunits compared to cells on smooth Ti (PT) surfaces. α2 or β1 silenced cells exhibited increased cell number and decreased differentiation on SLA compared to wild-type cells. Wild-type cells on SLA possessed an elongated morphology with reduced cell area, increased cell thickness, and more apparent contact points. Cells on PT exhibited greater spreading and were relatively flat. Silenced cells possessed a morphology and phenotype similar to wild-type cells grown on PT. These observations indicate that surface microroughness affects cell response via α2β1 integrin signaling, resulting in a cell shape that promotes osteoblastic differentiation.
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Affiliation(s)
- Min Lai
- Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia; College of Bioengineering, Chongqing University, Chongqing, China; College of Life Science, Jiangsu Normal University, Xuzhou, Jiangsu Province, China
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18
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Liu B, Yu HH, Ng TW, Paterson DL, Velkov T, Li J, Fu J. Nanoscale focused ion beam tomography of single bacterial cells for assessment of antibiotic effects. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2014; 20:537-547. [PMID: 24589280 DOI: 10.1017/s1431927614000026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Antibiotic resistance is a major risk to human health, and to provide valuable insights into mechanisms of resistance, innovative methods are needed to examine the cellular responses to antibiotic treatment. Focused ion beam tomography is proposed to image and assess the detailed three-dimensional (3D) ultrastructure of single bacterial cells. By iteratively removing slices of thickness in the order of 10 nm, high magnification 2D images can be acquired by scanning electron microscopy at single-digit nanometer resolution. In this study, Klebsiella pneumoniae was treated with polymyxin B, and 3D models of both cell envelope and cytoplasm regions containing the nucleoid and ribosomes were reconstructed. The 3D volume containing the nucleoid and ribosomes was significantly smaller, and the cell length along the longitudinal axis was extended by 40% in the treated cells, implying stress responses to the drug treatment. More than a 200% increase in protrusions per unit surface area on the cell envelope was observed in the curvature analysis after treatment. Experiments by conventional transmission electron microscopy and atomic force microscopy were also performed, followed by comparison and discussions. In conclusion, the proposed 3D imaging method and associated analysis provide a unique tool for the assessment of antibiotic effects on multidrug-resistant bacteria at nanometer resolution.
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Affiliation(s)
- Boyin Liu
- 1 Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia
| | - Heidi H Yu
- 2 Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Tuck Wah Ng
- 1 Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia
| | - David L Paterson
- 3 Centre for Clinical Research, University of Queensland, Brisbane, QLD 4072, Australia
| | - Tony Velkov
- 2 Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Jian Li
- 2 Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
| | - Jing Fu
- 1 Department of Mechanical and Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia
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19
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Olderøy MØ, Lilledahl MB, Beckwith MS, Melvik JE, Reinholt F, Sikorski P, Brinchmann JE. Biochemical and structural characterization of neocartilage formed by mesenchymal stem cells in alginate hydrogels. PLoS One 2014; 9:e91662. [PMID: 24626259 PMCID: PMC3953515 DOI: 10.1371/journal.pone.0091662] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 02/12/2014] [Indexed: 11/18/2022] Open
Abstract
A popular approach to make neocartilage in vitro is to immobilize cells with chondrogenic potential in hydrogels. However, functional cartilage cannot be obtained by control of cells only, as function of cartilage is largely dictated by architecture of extracellular matrix (ECM). Therefore, characterization of the cells, coupled with structural and biochemical characterization of ECM, is essential in understanding neocartilage assembly to create functional implants in vitro. We focused on mesenchymal stem cells (MSC) immobilized in alginate hydrogels, and used immunohistochemistry (IHC) and gene expression analysis combined with advanced microscopy techniques to describe properties of cells and distribution and organization of the forming ECM. In particular, we used second harmonic generation (SHG) microscopy and focused ion beam/scanning electron microscopy (FIB/SEM) to study distribution and assembly of collagen. Samples with low cell seeding density (1e7 MSC/ml) showed type II collagen molecules distributed evenly through the hydrogel. However, SHG microscopy clearly indicated only pericellular localization of assembled fibrils. Their distribution was improved in hydrogels seeded with 5e7 MSC/ml. In those samples, FIB/SEM with nm resolution was used to visualize distribution of collagen fibrils in a three dimensional network extending from the pericellular region into the ECM. In addition, distribution of enzymes involved in procollagen processing were investigated in the alginate hydrogel by IHC. It was discovered that, at high cell seeding density, procollagen processing and fibril assembly was also occurring far away from the cell surface, indicating sufficient transport of procollagen and enzymes in the intercellular space. At lower cell seeding density, the concentration of enzymes involved in procollagen processing was presumably too low. FIB/SEM and SHG microscopy combined with IHC localization of specific proteins were shown to provide meaningful insight into ECM assembly of neocartilage, which will lead to better understanding of cartilage formation and development of new tissue engineering strategies.
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Affiliation(s)
- Magnus Ø. Olderøy
- The Norwegian Center for Stem Cell Research, Oslo University Hospital, Oslo, Norway
- * E-mail:
| | - Magnus B. Lilledahl
- Department of Physics, Norwegian University of Science and Technology, Trondheim, Norway
| | | | | | - Finn Reinholt
- Department of Pathology, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Pawel Sikorski
- Department of Physics, Norwegian University of Science and Technology, Trondheim, Norway
| | - Jan E. Brinchmann
- The Norwegian Center for Stem Cell Research, Oslo University Hospital, Oslo, Norway
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20
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Wierzbicki R, Købler C, Jensen MRB, Łopacińska J, Schmidt MS, Skolimowski M, Abeille F, Qvortrup K, Mølhave K. Mapping the complex morphology of cell interactions with nanowire substrates using FIB-SEM. PLoS One 2013; 8:e53307. [PMID: 23326412 PMCID: PMC3541134 DOI: 10.1371/journal.pone.0053307] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Accepted: 11/27/2012] [Indexed: 11/19/2022] Open
Abstract
Using high resolution focused ion beam scanning electron microscopy (FIB-SEM) we study the details of cell-nanostructure interactions using serial block face imaging. 3T3 Fibroblast cellular monolayers are cultured on flat glass as a control surface and on two types of nanostructured scaffold substrates made from silicon black (Nanograss) with low- and high nanowire density. After culturing for 72 hours the cells were fixed, heavy metal stained, embedded in resin, and processed with FIB-SEM block face imaging without removing the substrate. The sample preparation procedure, image acquisition and image post-processing were specifically optimised for cellular monolayers cultured on nanostructured substrates. Cells display a wide range of interactions with the nanostructures depending on the surface morphology, but also greatly varying from one cell to another on the same substrate, illustrating a wide phenotypic variability. Depending on the substrate and cell, we observe that cells could for instance: break the nanowires and engulf them, flatten the nanowires or simply reside on top of them. Given the complexity of interactions, we have categorised our observations and created an overview map. The results demonstrate that detailed nanoscale resolution images are required to begin understanding the wide variety of individual cells’ interactions with a structured substrate. The map will provide a framework for light microscopy studies of such interactions indicating what modes of interactions must be considered.
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Affiliation(s)
| | - Carsten Købler
- DTU Nanotech, Technical University of Denmark, Lyngby, Denmark
- DTU CEN, Technical University of Denmark, Lyngby, Denmark
| | | | | | | | | | - Fabien Abeille
- DTU Nanotech, Technical University of Denmark, Lyngby, Denmark
| | - Klaus Qvortrup
- Department of Biomedical Sciences, CFIM, University of Copenhagen, Copenhagen, Denmark
| | - Kristian Mølhave
- DTU Nanotech, Technical University of Denmark, Lyngby, Denmark
- * E-mail:
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21
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Wesche M, Hüske M, Yakushenko A, Brüggemann D, Mayer D, Offenhäusser A, Wolfrum B. A nanoporous alumina microelectrode array for functional cell-chip coupling. NANOTECHNOLOGY 2012; 23:495303. [PMID: 23150042 DOI: 10.1088/0957-4484/23/49/495303] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The design of electrode interfaces has a strong impact on cell-based bioelectronic applications. We present a new type of microelectrode array chip featuring a nanoporous alumina interface. The chip is fabricated in a combination of top-down and bottom-up processes using state-of-the-art clean room technology and self-assembled generation of nanopores by aluminum anodization. The electrode characteristics are investigated in phosphate buffered saline as well as under cell culture conditions. We show that the modified microelectrodes exhibit decreased impedance compared to planar microelectrodes, which is caused by a nanostructuring effect of the underlying gold during anodization. The stability and biocompatibility of the device are demonstrated by measuring action potentials from cardiomyocyte-like cells growing on top of the chip. Cross sections of the cell-surface interface reveal that the cell membrane seals the nanoporous alumina layer without bending into the sub-50 nm apertures. The nanoporous microelectrode array device may be used as a platform for combining extracellular recording of cell activity with stimulating topographical cues.
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Affiliation(s)
- Manuel Wesche
- Institute of Bioelectronics (PGI-8/ICS-8) and JARA-Fundamentals of Future Information Technology, Forschungszentrum Jülich, D-52425 Jülich, Germany
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22
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Borges AMG, Benetoli LO, Licínio MA, Zoldan VC, Santos-Silva MC, Assreuy J, Pasa AA, Debacher NA, Soldi V. Polymer films with surfaces unmodified and modified by non-thermal plasma as new substrates for cell adhesion. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2012; 33:1315-24. [PMID: 23827577 DOI: 10.1016/j.msec.2012.12.031] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 09/29/2012] [Accepted: 12/04/2012] [Indexed: 01/04/2023]
Abstract
The surface properties of biomaterials, such as wettability, polar group distribution, and topography, play important roles in the behavior of cell adhesion and proliferation. Gaseous plasma discharges are among the most common means to modify the surface of a polymer without affecting its properties. Herein, we describe the surface modification of poly(styrene) (PS) and poly(methyl methacrylate) (PMMA) films using atmospheric pressure plasma processing through exposure to a dielectric barrier discharge (DBD). After treatment the film surface showed significant changes from hydrophobic to hydrophilic as the water contact angle decreasing from 95° to 37°. All plasma-treated films developed more hydrophilic surfaces compared to untreated films, although the reasons for the change in the surface properties of PS and PMMA differed, that is, the PS showed chemical changes and in the case of PMMA they were topographical. Excellent adhesion and cell proliferation were observed in all films. In vitro studies employing flow cytometry showed that the proliferation of L929 cells was higher in the film formed by a 1:1 mixture of PS/PMMA, which is consistent with the results of a previous study. These findings suggest better adhesion of L929 onto the 1:1 PS/PMMA modified film, indicating that this system is a new candidate biomaterial for tissue engineering.
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Affiliation(s)
- A M G Borges
- Department of Chemistry, Federal University of Santa Catarina, 88040-900 Florianopolis, Brazil
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23
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Hanson L, Lin ZC, Xie C, Cui Y, Cui B. Characterization of the cell-nanopillar interface by transmission electron microscopy. NANO LETTERS 2012; 12:5815-20. [PMID: 23030066 DOI: 10.1021/nl303163y] [Citation(s) in RCA: 142] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Vertically aligned nanopillars can serve as excellent electrical, optical and mechanical platforms for biological studies. However, revealing the nature of the interface between the cell and the nanopillar is very challenging. In particular, a matter of debate is whether the cell membrane remains intact around the nanopillar. Here we present a detailed characterization of the cell-nanopillar interface by transmission electron microscopy. We examined cortical neurons growing on nanopillars with diameter 50-500 nm and heights 0.5-2 μm. We found that on nanopillars less than 300 nm in diameter, the cell membrane wraps around the entirety of the nanopillar without the nanopillar penetrating into the interior of the cell. On the other hand, the cell sits on top of arrays of larger, closely spaced nanopillars. We also observed that the membrane-surface gap of both cell bodies and neurites is smaller for nanopillars than for a flat substrate. These results support a tight interaction between the cell membrane and the nanopillars and previous findings of excellent sealing in electrophysiology recordings using nanopillar electrodes.
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Affiliation(s)
- Lindsey Hanson
- Department of Chemistry, Stanford University, Stanford, California 94305, USA
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24
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Al-Abboodi A, Fu J, Doran PM, Chan PP. Three-dimensional nanocharacterization of porous hydrogel with ion and electron beams. Biotechnol Bioeng 2012; 110:318-26. [DOI: 10.1002/bit.24612] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Revised: 07/08/2012] [Accepted: 07/10/2012] [Indexed: 11/07/2022]
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25
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Kim J, Kim DH, Lim KT, Seonwoo H, Park SH, Kim YR, Kim Y, Choung YH, Choung PH, Chung JH. Charged nanomatrices as efficient platforms for modulating cell adhesion and shape. Tissue Eng Part C Methods 2012; 18:913-23. [PMID: 22621374 DOI: 10.1089/ten.tec.2011.0731] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In this article, we describe the design and manipulation of charged nanomatrices and their application as efficient platforms for modulating cell behaviors. Using electrospraying technology and well designed biomaterials, poly(ɛ-caprolactone; PCL) and polyethylenimine, the negatively charged PCL nanomatrix (nPCL nanomatrix) and the positively charged PCL nanomatrix (pPCL nanomatrix) were fabricated. It was demonstrated that cell adhesion, affinity, and shape were sensitively modulated in negatively and positively charged nanomatrices. Our results showed that the pPCL nanomatrix promoted adhesion of NIH 3T3 fibroblast cells as compared to the nPCL nanomatrix. When fluid shear stress was applied, cell affinity on the pPCL nanomatrix increased even more. NIH 3T3 fibroblast cells adopted a relatively spherical shape on the pPCL nanomatrix while adopting an aligned, narrow shape on the nPCL nanomatrix. It was also found that charged nanomatrices influenced the cross-sectional cell shape. The cross-sectional cell shape on the pPCL nanomatrix was extremely flattened, whereas the cross-sectional cell shape was relatively round on the nPCL nanomatrix and some of the adhered cells floated. We also showed that the surfaces of the nPCL and pPCL nanomatrices adsorbed the different serum proteins. These results collectively demonstrated a combination of environmental factors including nanoscale structure, electrostatic forces, and absorption of biomolecules on charged substrates affected cell response in terms of cellular adhesion and shape.
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Affiliation(s)
- Jangho Kim
- Department of Biosystems & Biomaterials Science and Engineering, Seoul National University, Seoul, Republic of Korea
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26
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Friedmann A, Cismak A, Tautorat C, Koester PJ, Baumann W, Held J, Gaspar J, Ruther P, Paul O, Heilmann A. FIB preparation and SEM investigations for three-dimensional analysis of cell cultures on microneedle arrays. SCANNING 2012; 34:221-229. [PMID: 22076793 DOI: 10.1002/sca.20297] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Accepted: 09/23/2011] [Indexed: 05/31/2023]
Abstract
We report the investigation of the interfaces between microneedle arrays and cell cultures in patch-on-chip systems by using Focused Ion Beam (FIB) preparation and Scanning Electron Microscopy (SEM). First, FIB preparations of micro chips are made to determine the size and shape of the designed microneedles. In this essay, we investigate the cell-substrate interaction, especially the cell adhesion, and the microneedle's potential cell penetration. For this purpose, cross-sectional preparation of these hard/soft hybrid structures is performed by the FIB technology. By applying the FIB technology followed by high-resolution imaging with SEM, new insights into the cell-substrate interface can be received. One can clearly distinguish between cells that are only in contact with microneedles and cells that are penetrated by microneedles. A stack of slice images is collected by the application of the slice-and-view setup during FIB preparation and is used for three-dimensional reconstruction of cells and micro-needles.
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Affiliation(s)
- A Friedmann
- Fraunhofer Institute for Mechanics of Materials IWM, Halle (Saale), Germany.
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27
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Advanced microscopy techniques to assess solid-state properties of inhalation medicines. Adv Drug Deliv Rev 2012; 64:369-82. [PMID: 22120022 DOI: 10.1016/j.addr.2011.11.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Revised: 11/07/2011] [Accepted: 11/11/2011] [Indexed: 11/22/2022]
Abstract
Efficient control and characterisation of the physico-chemical properties of active pharmaceutical ingredients (APIs) and excipients for orally inhaled drug products (OIDPs) are critical to successful product development. Control and reduction of risk require the introduction of a material science based approach to product development and the use of advanced analytical tools in understanding how the solid-state properties of the input materials influence structure and product functionality. The key issues to be addressed, at a microscopic scale, are understanding how the critical quality attributes of input materials influence surface, interfacial and particulate interactions within OIDPs. This review offers an in-depth discussion on the use of advanced microscopy techniques in characterising of the solid-state properties of particulate materials for OIDPs. The review covers the fundamental principles of the techniques, instrumentation types, data interpretation and specific applications in relation to the product development of OIDPs.
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