1
|
Foo KY, Shaddy B, Murgoitio-Esandi J, Hepburn MS, Li J, Mowla A, Sanderson RW, Vahala D, Amos SE, Choi YS, Oberai AA, Kennedy BF. Tumor spheroid elasticity estimation using mechano-microscopy combined with a conditional generative adversarial network. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2024; 255:108362. [PMID: 39163784 DOI: 10.1016/j.cmpb.2024.108362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 07/26/2024] [Accepted: 07/30/2024] [Indexed: 08/22/2024]
Abstract
BACKGROUND AND OBJECTIVES Techniques for imaging the mechanical properties of cells are needed to study how cell mechanics influence cell function and disease progression. Mechano-microscopy (a high-resolution variant of compression optical coherence elastography) generates elasticity images of a sample undergoing compression from the phase difference between optical coherence microscopy (OCM) B-scans. However, the existing mechano-microscopy signal processing chain (referred to as the algebraic method) assumes the sample stress is uniaxial and axially uniform, such that violation of these assumptions reduces the accuracy and precision of elasticity images. Furthermore, it does not account for prior information regarding the sample geometry or mechanical property distribution. In this study, we investigate the feasibility of training a conditional generative adversarial network (cGAN) to generate elasticity images from phase difference images of samples containing a cell spheroid embedded in a hydrogel. METHODS To construct the cGAN training and simulated test sets, we generated 30,000 artificial elasticity images using a parametric model and computed the corresponding phase difference images using finite element analysis to simulate compression applied to the artificial samples. We also imaged real MCF7 breast tumor spheroids embedded in hydrogel using mechano-microscopy to construct the experimental test set and evaluated the cGAN using the algebraic elasticity images and co-registered OCM and confocal fluorescence microscopy (CFM) images. RESULTS Comparison with the simulated test set ground truth elasticity images shows the cGAN produces a lower root mean square error (median: 3.47 kPa, 95 % confidence interval (CI) [3.41, 3.52]) than the algebraic method (median: 4.91 kPa, 95 % CI [4.85, 4.97]). For the experimental test set, the cGAN elasticity images contain features resembling stiff nuclei at locations corresponding to nuclei seen in the algebraic elasticity, OCM, and CFM images. Furthermore, the cGAN elasticity images are higher resolution and more robust to noise than the algebraic elasticity images. CONCLUSIONS The cGAN elasticity images exhibit better accuracy, spatial resolution, sensitivity, and robustness to noise than the algebraic elasticity images for both simulated and real experimental data.
Collapse
Affiliation(s)
- Ken Y Foo
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and Centre for Medical Research, The University of Western Australia, Perth, WA, Australia; Department of Electrical, Electronic & Computer Engineering, School of Engineering, The University of Western Australia, Perth, WA, Australia.
| | - Bryan Shaddy
- Department of Aerospace and Mechanical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - Javier Murgoitio-Esandi
- Department of Aerospace and Mechanical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - Matt S Hepburn
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and Centre for Medical Research, The University of Western Australia, Perth, WA, Australia; Department of Electrical, Electronic & Computer Engineering, School of Engineering, The University of Western Australia, Perth, WA, Australia; Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziadzka 5, 87-100 Toruń, Poland
| | - Jiayue Li
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and Centre for Medical Research, The University of Western Australia, Perth, WA, Australia; Department of Electrical, Electronic & Computer Engineering, School of Engineering, The University of Western Australia, Perth, WA, Australia; Australian Research Council Centre for Personalised Therapeutics Technologies, Melbourne, VIC, Australia
| | - Alireza Mowla
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and Centre for Medical Research, The University of Western Australia, Perth, WA, Australia; Department of Electrical, Electronic & Computer Engineering, School of Engineering, The University of Western Australia, Perth, WA, Australia
| | - Rowan W Sanderson
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and Centre for Medical Research, The University of Western Australia, Perth, WA, Australia; Department of Electrical, Electronic & Computer Engineering, School of Engineering, The University of Western Australia, Perth, WA, Australia
| | - Danielle Vahala
- School of Human Sciences, The University of Western Australia, Perth, WA, Australia
| | - Sebastian E Amos
- School of Human Sciences, The University of Western Australia, Perth, WA, Australia
| | - Yu Suk Choi
- School of Human Sciences, The University of Western Australia, Perth, WA, Australia
| | - Assad A Oberai
- Department of Aerospace and Mechanical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - Brendan F Kennedy
- BRITElab, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands and Centre for Medical Research, The University of Western Australia, Perth, WA, Australia; Department of Electrical, Electronic & Computer Engineering, School of Engineering, The University of Western Australia, Perth, WA, Australia; Australian Research Council Centre for Personalised Therapeutics Technologies, Melbourne, VIC, Australia
| |
Collapse
|
2
|
Hilai K, Grubich D, Akrawi M, Zhu H, Zaghloul R, Shi C, Do M, Zhu D, Zhang J. Mechanical evolution of metastatic cancer cells in three-dimensional microenvironment. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.27.601015. [PMID: 39005477 PMCID: PMC11244934 DOI: 10.1101/2024.06.27.601015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Cellular biomechanics plays critical roles in cancer metastasis and tumor progression. Existing studies on cancer cell biomechanics are mostly conducted in flat 2D conditions, where cells' behavior can differ considerably from those in 3D physiological environments. Despite great advances in developing 3D in vitro models, probing cellular elasticity in 3D conditions remains a major challenge for existing technologies. In this work, we utilize optical Brillouin microscopy to longitudinally acquire mechanical images of growing cancerous spheroids over the period of eight days. The dense mechanical mapping from Brillouin microscopy enables us to extract spatially resolved and temporally evolving mechanical features that were previously inaccessible. Using an established machine learning algorithm, we demonstrate that incorporating these extracted mechanical features significantly improves the classification accuracy of cancer cells, from 74% to 95%. Building on this finding, we have developed a deep learning pipeline capable of accurately differentiating cancerous spheroids from normal ones solely using Brillouin images, suggesting the mechanical features of cancer cells could potentially serve as a new biomarker in cancer classification and detection.
Collapse
Affiliation(s)
- Karlin Hilai
- Department of Biomedical Engineering, Wayne State University, Detroit, MI 48202, USA
| | - Daniil Grubich
- Department of Biomedical Engineering, Wayne State University, Detroit, MI 48202, USA
| | - Marcus Akrawi
- Department of Biomedical Engineering, Wayne State University, Detroit, MI 48202, USA
| | - Hui Zhu
- Department of Computer Science, Wayne State University, Detroit, MI, 48202, USA
| | - Razanne Zaghloul
- Department of Biomedical Engineering, Wayne State University, Detroit, MI 48202, USA
| | - Chenjun Shi
- Department of Biomedical Engineering, Wayne State University, Detroit, MI 48202, USA
| | - Man Do
- Department of Biomedical Engineering, Wayne State University, Detroit, MI 48202, USA
| | - Dongxiao Zhu
- Department of Computer Science, Wayne State University, Detroit, MI, 48202, USA
| | - Jitao Zhang
- Department of Biomedical Engineering, Wayne State University, Detroit, MI 48202, USA
| |
Collapse
|
3
|
Bilenca A, Prevedel R, Scarcelli G. Current state of stimulated Brillouin scattering microscopy for the life sciences. JPHYS PHOTONICS 2024; 6:032001. [PMID: 38939757 PMCID: PMC11200595 DOI: 10.1088/2515-7647/ad5506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 04/21/2024] [Accepted: 06/05/2024] [Indexed: 06/29/2024] Open
Abstract
Stimulated Brillouin scattering (SBS) microscopy is a nonlinear all-optical imaging method that provides mechanical contrast based on the interaction of laser radiation and acoustical vibrational modes. Featuring high mechanical specificity and sensitivity, three-dimensional sectioning, and practical imaging times, SBS microscopy with (quasi) continuous wave excitation is rapidly advancing as a promising imaging tool for label-free visualization of viscoelastic information of materials and living biological systems. In this article, we introduce the theory of SBS microscopy and review the current state-of-the-art as well as recent innovations, including different approaches to system designs and data analysis. In particular, various performance parameters of SBS microscopy and its applications in the life sciences are described and discussed. Future perspectives for SBS microscopy are also presented.
Collapse
Affiliation(s)
- Alberto Bilenca
- Biomedical Engineering Department, Ben-Gurion University of the Negev, 1 Ben Gurion Blvd, Be’er-Sheva 84105, Israel
- Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, 1 Ben Gurion Blvd, Be’er-Sheva 84105, Israel
| | - Robert Prevedel
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Giuliano Scarcelli
- Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, United States of America
| |
Collapse
|
4
|
Antonacci G, Vanna R, Ventura M, Schiavone ML, Sobacchi C, Behrouzitabar M, Polli D, Manzoni C, Cerullo G. Birefringence-induced phase delay enables Brillouin mechanical imaging in turbid media. Nat Commun 2024; 15:5202. [PMID: 38898004 PMCID: PMC11187154 DOI: 10.1038/s41467-024-49419-2] [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: 01/11/2024] [Accepted: 06/04/2024] [Indexed: 06/21/2024] Open
Abstract
Acoustic vibrations of matter convey fundamental viscoelastic information that can be optically retrieved by hyperfine spectral analysis of the inelastic Brillouin scattered light. Increasing evidence of the central role of the viscoelastic properties in biological processes has stimulated the rise of non-contact Brillouin microscopy, yet this method faces challenges in turbid samples due to overwhelming elastic background light. Here, we introduce a common-path Birefringence-Induced Phase Delay (BIPD) filter to disentangle the polarization states of the Brillouin and Rayleigh signals, enabling the rejection of the background light using a polarizer. We demonstrate a 65 dB extinction ratio in a single optical pass collecting Brillouin spectra in extremely scattering environments and across highly reflective interfaces. We further employ the BIPD filter to image bone tissues from a mouse model of osteopetrosis, highlighting altered biomechanical properties compared to the healthy control. Results herald new opportunities in mechanobiology where turbid biological samples remain poorly characterized.
Collapse
Affiliation(s)
| | - Renzo Vanna
- CNR-Istituto di Fotonica e Nanotecnologie, CNR-IFN, Piazza Leonardo da Vinci 32, 20133, Milano, Italy
| | - Marco Ventura
- CNR-Istituto di Fotonica e Nanotecnologie, CNR-IFN, Piazza Leonardo da Vinci 32, 20133, Milano, Italy
| | | | - Cristina Sobacchi
- IRCCS Humanitas Research Hospital, via Manzoni 56, 20089, Rozzano (Milano), Italy
- CNR-Istituto di Ricerca Genetica e Biomedica (CNR-IRGB), UOS di Milano, via Fantoli 16/15, 20138, Milano, Italy
| | - Morteza Behrouzitabar
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milano, Italy
| | - Dario Polli
- Specto Photonics, Via Giulio e Corrado Venini 18, 20127, Milano, Italy
- CNR-Istituto di Fotonica e Nanotecnologie, CNR-IFN, Piazza Leonardo da Vinci 32, 20133, Milano, Italy
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milano, Italy
| | - Cristian Manzoni
- CNR-Istituto di Fotonica e Nanotecnologie, CNR-IFN, Piazza Leonardo da Vinci 32, 20133, Milano, Italy.
| | - Giulio Cerullo
- CNR-Istituto di Fotonica e Nanotecnologie, CNR-IFN, Piazza Leonardo da Vinci 32, 20133, Milano, Italy
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133, Milano, Italy
| |
Collapse
|
5
|
Möckel C, Beck T, Kaliman S, Abuhattum S, Kim K, Kolb J, Wehner D, Zaburdaev V, Guck J. Estimation of the mass density of biological matter from refractive index measurements. BIOPHYSICAL REPORTS 2024; 4:100156. [PMID: 38718671 PMCID: PMC11090064 DOI: 10.1016/j.bpr.2024.100156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 04/04/2024] [Accepted: 04/19/2024] [Indexed: 05/16/2024]
Abstract
The quantification of physical properties of biological matter gives rise to novel ways of understanding functional mechanisms. One of the basic biophysical properties is the mass density (MD). It affects the dynamics in sub-cellular compartments and plays a major role in defining the opto-acoustical properties of cells and tissues. As such, the MD can be connected to the refractive index (RI) via the well known Lorentz-Lorenz relation, which takes into account the polarizability of matter. However, computing the MD based on RI measurements poses a challenge, as it requires detailed knowledge of the biochemical composition of the sample. Here we propose a methodology on how to account for assumptions about the biochemical composition of the sample and respective RI measurements. To this aim, we employ the Biot mixing rule of RIs alongside the assumption of volume additivity to find an approximate relation of MD and RI. We use Monte-Carlo simulations and Gaussian propagation of uncertainty to obtain approximate analytical solutions for the respective uncertainties of MD and RI. We validate this approach by applying it to a set of well-characterized complex mixtures given by bovine milk and intralipid emulsion and employ it to estimate the MD of living zebrafish (Danio rerio) larvae trunk tissue. Our results illustrate the importance of implementing this methodology not only for MD estimations but for many other related biophysical problems, such as mechanical measurements using Brillouin microscopy and transient optical coherence elastography.
Collapse
Affiliation(s)
- Conrad Möckel
- Max Planck Institute for the Science of Light, Erlangen, Germany; Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany; Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Timon Beck
- Max Planck Institute for the Science of Light, Erlangen, Germany; Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany
| | - Sara Kaliman
- Max Planck Institute for the Science of Light, Erlangen, Germany; Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany
| | - Shada Abuhattum
- Max Planck Institute for the Science of Light, Erlangen, Germany; Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany
| | - Kyoohyun Kim
- Max Planck Institute for the Science of Light, Erlangen, Germany; Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany
| | - Julia Kolb
- Max Planck Institute for the Science of Light, Erlangen, Germany; Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany; Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Daniel Wehner
- Max Planck Institute for the Science of Light, Erlangen, Germany; Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany
| | - Vasily Zaburdaev
- Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany; Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Jochen Guck
- Max Planck Institute for the Science of Light, Erlangen, Germany; Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany; Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.
| |
Collapse
|
6
|
Zorbas C, Soenmez A, Léger J, De Vleeschouwer C, Lafontaine DL. Detecting material state changes in the nucleolus by label-free digital holographic microscopy. EMBO Rep 2024; 25:2786-2811. [PMID: 38654122 PMCID: PMC11169520 DOI: 10.1038/s44319-024-00134-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 03/04/2024] [Accepted: 03/20/2024] [Indexed: 04/25/2024] Open
Abstract
Ribosome biogenesis is initiated in the nucleolus, a multiphase biomolecular condensate formed by liquid-liquid phase separation. The nucleolus is a powerful disease biomarker and stress biosensor whose morphology reflects function. Here we have used digital holographic microscopy (DHM), a label-free quantitative phase contrast microscopy technique, to detect nucleoli in adherent and suspension human cells. We trained convolutional neural networks to detect and quantify nucleoli automatically on DHM images. Holograms containing cell optical thickness information allowed us to define a novel index which we used to distinguish nucleoli whose material state had been modulated optogenetically by blue-light-induced protein aggregation. Nucleoli whose function had been impacted by drug treatment or depletion of ribosomal proteins could also be distinguished. We explored the potential of the technology to detect other natural and pathological condensates, such as those formed upon overexpression of a mutant form of huntingtin, ataxin-3, or TDP-43, and also other cell assemblies (lipid droplets). We conclude that DHM is a powerful tool for quantitatively characterizing nucleoli and other cell assemblies, including their material state, without any staining.
Collapse
Affiliation(s)
- Christiane Zorbas
- RNA Molecular Biology, Fonds de la Recherche Scientifique (F.R.S./FNRS), Université libre de Bruxelles (ULB), Biopark campus, B-6041, Gosselies, Belgium
| | - Aynur Soenmez
- RNA Molecular Biology, Fonds de la Recherche Scientifique (F.R.S./FNRS), Université libre de Bruxelles (ULB), Biopark campus, B-6041, Gosselies, Belgium
| | - Jean Léger
- ICTEAM-ELEN, Fonds de la Recherche Scientifique (F.R.S./FNRS), UCLouvain, B-1348, Louvain-la-Neuve, Belgium
| | - Christophe De Vleeschouwer
- ICTEAM-ELEN, Fonds de la Recherche Scientifique (F.R.S./FNRS), UCLouvain, B-1348, Louvain-la-Neuve, Belgium
| | - Denis Lj Lafontaine
- RNA Molecular Biology, Fonds de la Recherche Scientifique (F.R.S./FNRS), Université libre de Bruxelles (ULB), Biopark campus, B-6041, Gosselies, Belgium.
| |
Collapse
|
7
|
Kasprzycka W, Szumigraj W, Wachulak P, Trafny EA. New approaches for low phototoxicity imaging of living cells and tissues. Bioessays 2024; 46:e2300122. [PMID: 38514402 DOI: 10.1002/bies.202300122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 03/06/2024] [Accepted: 03/07/2024] [Indexed: 03/23/2024]
Abstract
Fluorescence microscopy is a powerful tool used in scientific and medical research, but it is inextricably linked to phototoxicity. Neglecting phototoxicity can lead to erroneous or inconclusive results. Recently, several reports have addressed this issue, but it is still underestimated by many researchers, even though it can lead to cell death. Phototoxicity can be reduced by appropriate microscopic techniques and carefully designed experiments. This review focuses on recent strategies to reduce phototoxicity in microscopic imaging of living cells and tissues. We describe digital image processing and new hardware solutions. We point out new modifications of microscopy methods and hope that this review will interest microscopy hardware engineers. Our aim is to underscore the challenges and potential solutions integral to the design of microscopy systems. Simultaneously, we intend to engage biologists, offering insight into the latest technological advancements in imaging that can enhance their understanding and practice.
Collapse
Affiliation(s)
- Wiktoria Kasprzycka
- Biomedical Engineering Centre, Institute of Optoelectronics, Military University of Technology, Kaliskiego, Warsaw, Poland
| | - Wiktoria Szumigraj
- Biomedical Engineering Centre, Institute of Optoelectronics, Military University of Technology, Kaliskiego, Warsaw, Poland
| | - Przemysław Wachulak
- Laser Technology Division, Institute of Optoelectronics, Military University of Technology, Kaliskiego, Warsaw, Poland
| | - Elżbieta Anna Trafny
- Biomedical Engineering Centre, Institute of Optoelectronics, Military University of Technology, Kaliskiego, Warsaw, Poland
| |
Collapse
|
8
|
Coker ZN, Troyanova-Wood M, Steelman ZA, Ibey BL, Bixler JN, Scully MO, Yakovlev VV. Brillouin microscopy monitors rapid responses in subcellular compartments. PHOTONIX 2024; 5:9. [PMID: 38618142 PMCID: PMC11006764 DOI: 10.1186/s43074-024-00123-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 02/12/2024] [Accepted: 03/11/2024] [Indexed: 04/16/2024]
Abstract
Measurements and imaging of the mechanical response of biological cells are critical for understanding the mechanisms of many diseases, and for fundamental studies of energy, signal and force transduction. The recent emergence of Brillouin microscopy as a powerful non-contact, label-free way to non-invasively and non-destructively assess local viscoelastic properties provides an opportunity to expand the scope of biomechanical research to the sub-cellular level. Brillouin spectroscopy has recently been validated through static measurements of cell viscoelastic properties, however, fast (sub-second) measurements of sub-cellular cytomechanical changes have yet to be reported. In this report, we utilize a custom multimodal spectroscopy system to monitor for the very first time the rapid viscoelastic response of cells and subcellular structures to a short-duration electrical impulse. The cytomechanical response of three subcellular structures - cytoplasm, nucleoplasm, and nucleoli - were monitored, showing distinct mechanical changes despite an identical stimulus. Through this pioneering transformative study, we demonstrate the capability of Brillouin spectroscopy to measure rapid, real-time biomechanical changes within distinct subcellular compartments. Our results support the promising future of Brillouin spectroscopy within the broad scope of cellular biomechanics.
Collapse
Affiliation(s)
- Zachary N. Coker
- Department of Physics & Astronomy, Texas A&M University, 4242 TAMU, College Station, TX 77843 USA
- SAIC, Fort Sam Houston, TX 78234 USA
| | | | - Zachary A. Steelman
- Air Force Research Laboratory, JBSA Fort Sam Houston, Fort Sam Houston, TX 78234 USA
| | - Bennett L. Ibey
- Air Force Research Laboratory, JBSA Fort Sam Houston, Fort Sam Houston, TX 78234 USA
| | - Joel N. Bixler
- Air Force Research Laboratory, JBSA Fort Sam Houston, Fort Sam Houston, TX 78234 USA
| | - Marlan O. Scully
- Department of Physics & Astronomy, Texas A&M University, 4242 TAMU, College Station, TX 77843 USA
- Institute for Quantum Science and Engineering, Texas A&M University, College Station, TX 77843 USA
| | - Vladislav V. Yakovlev
- Department of Physics & Astronomy, Texas A&M University, 4242 TAMU, College Station, TX 77843 USA
- Institute for Quantum Science and Engineering, Texas A&M University, College Station, TX 77843 USA
- Department of Biomedical Engineering, Texas A&M University, 3120 TAMU, 101 Bizzell Street, College Station, TX 77843 USA
| |
Collapse
|
9
|
Kabakova I, Zhang J, Xiang Y, Caponi S, Bilenca A, Guck J, Scarcelli G. Brillouin microscopy. NATURE REVIEWS. METHODS PRIMERS 2024; 4:8. [PMID: 39391288 PMCID: PMC11465583 DOI: 10.1038/s43586-023-00286-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/30/2023] [Indexed: 10/12/2024]
Abstract
The field of Brillouin microscopy and imaging was established approximately 20 years ago, thanks to the development of non-scanning high-resolution optical spectrometers. Since then, the field has experienced rapid expansion, incorporating technologies from telecommunications, astrophotonics, multiplexed microscopy, quantum optics and machine learning. Consequently, these advancements have led to much-needed improvements in imaging speed, spectral resolution and sensitivity. The progress in Brillouin microscopy is driven by a strong demand for label-free and contact-free methods to characterize the mechanical properties of biomaterials at the cellular and subcellular scales. Understanding the local biomechanics of cells and tissues has become crucial in predicting cellular fate and tissue pathogenesis. This Primer aims to provide a comprehensive overview of the methods and applications of Brillouin microscopy. It includes key demonstrations of Brillouin microscopy and imaging that can serve as a reference for the existing research community and new adopters of this technology. The article concludes with an outlook, presenting the authors' vision for future developments in this vibrant field. The Primer also highlights specific examples where Brillouin microscopy can have a transformative impact on biology and biomedicine.
Collapse
Affiliation(s)
- Irina Kabakova
- School of Mathematical and Physical Sciences, University of Technology Sydney, Sydney, New South Wales, Australia
| | - Jitao Zhang
- Department of Biomedical Engineering, Wayne State University, Detroit, MI, USA
| | - Yuchen Xiang
- Department of Metabolism, Digestion & Reproduction, Imperial College London, London, UK
| | - Silvia Caponi
- Istituto Officina dei Materiali–National Research Council (IOM-CNR)–Research Unit in Perugia, c/o Department of Physics and Geology, University of Perugia, Perugia, Italy
| | - Alberto Bilenca
- Biomedical Engineering Department, Ben-Gurion University of the Negev, Be’er-Sheva, Israel
| | - Jochen Guck
- Max Planck Institute for the Science of Light, Erlangen, Germany
- Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany
| | - Giuliano Scarcelli
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA
- Maryland Biophysics Program, University of Maryland, College Park, MD, USA
| |
Collapse
|
10
|
Yang F, Bevilacqua C, Hambura S, Neves A, Gopalan A, Watanabe K, Govendir M, Bernabeu M, Ellenberg J, Diz-Muñoz A, Köhler S, Rapti G, Jechlinger M, Prevedel R. Pulsed stimulated Brillouin microscopy enables high-sensitivity mechanical imaging of live and fragile biological specimens. Nat Methods 2023; 20:1971-1979. [PMID: 37884795 PMCID: PMC10703689 DOI: 10.1038/s41592-023-02054-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 09/20/2023] [Indexed: 10/28/2023]
Abstract
Brillouin microscopy is an emerging optical elastography technique capable of assessing mechanical properties of biological samples in a three-dimensional, all-optical and noncontact fashion. The typically weak Brillouin scattering signal can be substantially enhanced via a stimulated Brillouin scattering (SBS) process; however, current implementations require high pump powers, which prohibit applications to photosensitive or live imaging of biological samples. Here we present a pulsed SBS scheme that takes advantage of the nonlinearity of the pump-probe interaction. In particular, we show that the required pump laser power can be decreased ~20-fold without affecting the signal levels or spectral precision. We demonstrate the low phototoxicity and high specificity of our pulsed SBS approach by imaging, with subcellular detail, sensitive single cells, zebrafish larvae, mouse embryos and adult Caenorhabditis elegans. Furthermore, our method permits observing the mechanics of organoids and C. elegans embryos over time, opening up further possibilities for the field of mechanobiology.
Collapse
Affiliation(s)
- Fan Yang
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany.
- Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, China.
| | - Carlo Bevilacqua
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
- Collaboration for joint PhD degree between EMBL and Heidelberg University, Faculty of Biosciences, Heidelberg, Germany
| | - Sebastian Hambura
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Ana Neves
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
- Collaboration for joint PhD degree between EMBL and Heidelberg University, Faculty of Biosciences, Heidelberg, Germany
| | - Anusha Gopalan
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
- Collaboration for joint PhD degree between EMBL and Heidelberg University, Faculty of Biosciences, Heidelberg, Germany
| | - Koki Watanabe
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Matt Govendir
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
- European Molecular Biology Laboratory Barcelona, Barcelona, Spain
| | - Maria Bernabeu
- European Molecular Biology Laboratory Barcelona, Barcelona, Spain
| | - Jan Ellenberg
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Alba Diz-Muñoz
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Simone Köhler
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Georgia Rapti
- Developmental Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
- Interdisciplinary Center of Neurosciences, Heidelberg University, Heidelberg, Germany
- Epigenetics and Neurobiology Unit, European Molecular Biology Laboratory, Rome, Italy
| | - Martin Jechlinger
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
- MOLIT Institute for Personalized Medicine gGmbH, Heilbronn, Germany
| | - Robert Prevedel
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany.
- Developmental Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany.
- Interdisciplinary Center of Neurosciences, Heidelberg University, Heidelberg, Germany.
- Epigenetics and Neurobiology Unit, European Molecular Biology Laboratory, Rome, Italy.
- Molecular Medicine Partnership Unit, European Molecular Biology Laboratory, Heidelberg, Germany.
- German Center for Lung Research (DZL), Heidelberg, Germany.
| |
Collapse
|
11
|
Shi C, Handler C, Florn H, Zhang J. Monitoring the Mechanical Evolution of Tissue During Neural Tube Closure of Chick Embryo. J Vis Exp 2023:10.3791/66117. [PMID: 38009716 PMCID: PMC11456995 DOI: 10.3791/66117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023] Open
Abstract
Neural tube closure (NTC) is a critical process during embryonic development. Failure in this process can lead to neural tube defects, causing congenital malformations or even mortality. NTC involves a series of mechanisms on genetic, molecular, and mechanical levels. While mechanical regulation has become an increasingly attractive topic in recent years, it remains largely unexplored due to the lack of suitable technology for conducting mechanical testing of 3D embryonic tissue in situ. In response, we have developed a protocol for quantifying the mechanical properties of chicken embryonic tissue in a non-contact and non-invasive manner. This is achieved by integrating a confocal Brillouin microscope with an on-stage incubation system. To probe tissue mechanics, a pre-cultured embryo is collected and transferred to an on-stage incubator for ex ovo culture. Simultaneously, the mechanical images of the neural plate tissue are acquired by the Brillouin microscope at different time points during development. This protocol includes detailed descriptions of sample preparation, the implementation of Brillouin microscopy experiments, and data post-processing and analysis. By following this protocol, researchers can study the mechanical evolution of embryonic tissue during development longitudinally.
Collapse
Affiliation(s)
- Chenjun Shi
- Department of Biomedical Engineering, College of Engineering, Wayne State University
| | | | - Haden Florn
- Department of Biomedical Engineering, College of Engineering, Wayne State University
| | - Jitao Zhang
- Department of Biomedical Engineering, College of Engineering, Wayne State University;
| |
Collapse
|
12
|
Yousafzai MS, Hammer JA. Using Biosensors to Study Organoids, Spheroids and Organs-on-a-Chip: A Mechanobiology Perspective. BIOSENSORS 2023; 13:905. [PMID: 37887098 PMCID: PMC10605946 DOI: 10.3390/bios13100905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 09/13/2023] [Accepted: 09/19/2023] [Indexed: 10/28/2023]
Abstract
The increasing popularity of 3D cell culture models is being driven by the demand for more in vivo-like conditions with which to study the biochemistry and biomechanics of numerous biological processes in health and disease. Spheroids and organoids are 3D culture platforms that self-assemble and regenerate from stem cells, tissue progenitor cells or cell lines, and that show great potential for studying tissue development and regeneration. Organ-on-a-chip approaches can be used to achieve spatiotemporal control over the biochemical and biomechanical signals that promote tissue growth and differentiation. These 3D model systems can be engineered to serve as disease models and used for drug screens. While culture methods have been developed to support these 3D structures, challenges remain to completely recapitulate the cell-cell and cell-matrix biomechanical interactions occurring in vivo. Understanding how forces influence the functions of cells in these 3D systems will require precise tools to measure such forces, as well as a better understanding of the mechanobiology of cell-cell and cell-matrix interactions. Biosensors will prove powerful for measuring forces in both of these contexts, thereby leading to a better understanding of how mechanical forces influence biological systems at the cellular and tissue levels. Here, we discussed how biosensors and mechanobiological research can be coupled to develop accurate, physiologically relevant 3D tissue models to study tissue development, function, malfunction in disease, and avenues for disease intervention.
Collapse
Affiliation(s)
- Muhammad Sulaiman Yousafzai
- Cell and Developmental Biology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - John A. Hammer
- Cell and Developmental Biology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| |
Collapse
|
13
|
Zhu Y, Zhang M, Sun Q, Wang X, Li X, Li Q. Advanced Mechanical Testing Technologies at the Cellular Level: The Mechanisms and Application in Tissue Engineering. Polymers (Basel) 2023; 15:3255. [PMID: 37571149 PMCID: PMC10422338 DOI: 10.3390/polym15153255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 07/24/2023] [Accepted: 07/28/2023] [Indexed: 08/13/2023] Open
Abstract
Mechanics, as a key physical factor which affects cell function and tissue regeneration, is attracting the attention of researchers in the fields of biomaterials, biomechanics, and tissue engineering. The macroscopic mechanical properties of tissue engineering scaffolds have been studied and optimized based on different applications. However, the mechanical properties of the overall scaffold materials are not enough to reveal the mechanical mechanism of the cell-matrix interaction. Hence, the mechanical detection of cell mechanics and cellular-scale microenvironments has become crucial for unraveling the mechanisms which underly cell activities and which are affected by physical factors. This review mainly focuses on the advanced technologies and applications of cell-scale mechanical detection. It summarizes the techniques used in micromechanical performance analysis, including atomic force microscope (AFM), optical tweezer (OT), magnetic tweezer (MT), and traction force microscope (TFM), and analyzes their testing mechanisms. In addition, the application of mechanical testing techniques to cell mechanics and tissue engineering scaffolds, such as hydrogels and porous scaffolds, is summarized and discussed. Finally, it highlights the challenges and prospects of this field. This review is believed to provide valuable insights into micromechanics in tissue engineering.
Collapse
Affiliation(s)
- Yingxuan Zhu
- School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou 450001, China
- National Center for International Joint Research of Micro-nano Moulding Technology, Zhengzhou University, Zhengzhou 450001, China
| | - Mengqi Zhang
- School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou 450001, China
- National Center for International Joint Research of Micro-nano Moulding Technology, Zhengzhou University, Zhengzhou 450001, China
| | - Qingqing Sun
- School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Xiaofeng Wang
- School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou 450001, China
- National Center for International Joint Research of Micro-nano Moulding Technology, Zhengzhou University, Zhengzhou 450001, China
| | - Xiaomeng Li
- School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou 450001, China
- National Center for International Joint Research of Micro-nano Moulding Technology, Zhengzhou University, Zhengzhou 450001, China
| | - Qian Li
- School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou 450001, China
- National Center for International Joint Research of Micro-nano Moulding Technology, Zhengzhou University, Zhengzhou 450001, China
| |
Collapse
|
14
|
Shi C, Yan Y, Mehrmohammadi M, Zhang J. Versatile multimodal modality based on Brillouin light scattering and the photoacoustic effect. OPTICS LETTERS 2023; 48:3427-3430. [PMID: 37390147 PMCID: PMC11426331 DOI: 10.1364/ol.495361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 06/02/2023] [Indexed: 07/02/2023]
Abstract
Multimodal optical techniques are useful for the comprehensive characterization of material properties. In this work, we developed a new, to the best of our knowledge, multimodal technology that can simultaneously measure a subset of mechanical, optical, and acoustical properties of the sample and is based on the integration of Brillouin (Br) and photoacoustic (PA) microscopy. The proposed technique can acquire co-registered Br and PA signals from the sample. Importantly, using synergistic measurements of the speed of sound and Brillouin shift, the modality offers a new approach to quantifying the optical refractive index, which is a fundamental property of a material and is not accessible by either technique individually. As a proof of concept, we demonstrated the feasibility of integrating the two modalities and acquired the colocalized Br and time-resolved PA signals in a synthetic phantom made out of kerosene and CuSO4 aqueous solution. In addition, we measured the refractive index values of saline solutions and validated the result. Comparison with previously reported data showed a relative error of 0.3%. This further allowed us to directly quantify the longitudinal modulus of the sample with the colocalized Brillouin shift. While the scope of the current work is limited to introducing the combined Br-PA setup for the first time, we envision that this multimodal modality could open a new path for the multi-parametric analysis of material properties.
Collapse
Affiliation(s)
- Chenjun Shi
- Department of Biomedical Engineering, College of Engineering, Wayne State University, Detroit, MI 48202, USA
| | - Yan Yan
- Department of Imaging Science, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Mohammad Mehrmohammadi
- Department of Imaging Science, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY, 14642, USA
- Department of Biomedical Engineering, Hajim School of Engineering and Applied Sciences, University of Rochester, Rochester, NY, 14642, USA
| | - Jitao Zhang
- Department of Biomedical Engineering, College of Engineering, Wayne State University, Detroit, MI 48202, USA
| |
Collapse
|
15
|
Chow DM, Yun SH. Pulsed stimulated Brillouin microscopy. OPTICS EXPRESS 2023; 31:19818-19827. [PMID: 37381389 PMCID: PMC10316751 DOI: 10.1364/oe.489158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 04/24/2023] [Accepted: 05/10/2023] [Indexed: 06/30/2023]
Abstract
Stimulated Brillouin scattering is an emerging technique for probing the mechanical properties of biological samples. However, the nonlinear process requires high optical intensities to generate sufficient signal-to-noise ratio (SNR). Here, we show that the SNR of stimulated Brillouin scattering can exceed that of spontaneous Brillouin scattering with the same average power levels suitable for biological samples. We verify the theoretical prediction by developing a novel scheme using low duty cycle, nanosecond pulses for the pump and probe. A shot noise-limited SNR over 1000 was measured with a total average power of 10 mW for 2 ms or 50 mW for 200 µs integration on water samples. High-resolution maps of Brillouin frequency shift, linewidth, and gain amplitude from cells in vitro are obtained with a spectral acquisition time of 20 ms. Our results demonstrate the superior SNR of pulsed stimulated Brillouin over spontaneous Brillouin microscopy.
Collapse
Affiliation(s)
- Desmond M. Chow
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Seok-Hyun Yun
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Harvard-MIT Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| |
Collapse
|
16
|
Ghosh B, Agarwal K. Viewing life without labels under optical microscopes. Commun Biol 2023; 6:559. [PMID: 37231084 PMCID: PMC10212946 DOI: 10.1038/s42003-023-04934-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 05/12/2023] [Indexed: 05/27/2023] Open
Abstract
Optical microscopes today have pushed the limits of speed, quality, and observable space in biological specimens revolutionizing how we view life today. Further, specific labeling of samples for imaging has provided insight into how life functions. This enabled label-based microscopy to percolate and integrate into mainstream life science research. However, the use of labelfree microscopy has been mostly limited, resulting in testing for bio-application but not bio-integration. To enable bio-integration, such microscopes need to be evaluated for their timeliness to answer biological questions uniquely and establish a long-term growth prospect. The article presents key label-free optical microscopes and discusses their integrative potential in life science research for the unperturbed analysis of biological samples.
Collapse
|
17
|
Shi C, Yan Y, Mehrmohammadi M, Zhang J. A versatile multimodal optical modality based on Brillouin light scattering and photoacoustic effect. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.10.532144. [PMID: 36945550 PMCID: PMC10028970 DOI: 10.1101/2023.03.10.532144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/14/2023]
Abstract
Multimodal optical imaging techniques are useful for various applications, including imaging biological samples for providing comprehensive material properties. In this work, we developed a new modality that can measure a set of mechanical, optical, and acoustical properties of a sample at microscopic resolution, which is based on the integration of Brillouin (Br) and photoacoustic (PA) microscopy. The proposed multimodal imaging technique not only can acquire co-registered Br and PA signals but also allows us to utilize the sound speed measured by PA to quantify the sample’s refractive index, which is a fundamental property of the material and cannot be measured by either technique individually. We demonstrated the colocalization of Br and time-resolved PA signals in a synthetic phantom made of kerosene and CuSO 4 aqueous solution. In addition, we measured the refractive index of saline solutions and validated the result against published data with a relative error of 0.3 %. This multimodal Br-PA modality could open a new way for characterizing biological samples in physiological and pathological conditions.
Collapse
|
18
|
Leartprapun N, Adie SG. Recent advances in optical elastography and emerging opportunities in the basic sciences and translational medicine [Invited]. BIOMEDICAL OPTICS EXPRESS 2023; 14:208-248. [PMID: 36698669 PMCID: PMC9842001 DOI: 10.1364/boe.468932] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 11/29/2022] [Accepted: 11/29/2022] [Indexed: 05/28/2023]
Abstract
Optical elastography offers a rich body of imaging capabilities that can serve as a bridge between organ-level medical elastography and single-molecule biophysics. We review the methodologies and recent developments in optical coherence elastography, Brillouin microscopy, optical microrheology, and photoacoustic elastography. With an outlook toward maximizing the basic science and translational clinical impact of optical elastography technologies, we discuss potential ways that these techniques can integrate not only with each other, but also with supporting technologies and capabilities in other biomedical fields. By embracing cross-modality and cross-disciplinary interactions with these parallel fields, optical elastography can greatly increase its potential to drive new discoveries in the biomedical sciences as well as the development of novel biomechanics-based clinical diagnostics and therapeutics.
Collapse
Affiliation(s)
- Nichaluk Leartprapun
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York 14853, USA
- Present affiliation: Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Steven G. Adie
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York 14853, USA
| |
Collapse
|
19
|
Kurbanova B, Ashikbayeva Z, Amantayeva A, Sametova A, Blanc W, Gaipov A, Tosi D, Utegulov Z. Thermo-Visco-Elastometry of RF-Wave-Heated and Ablated Flesh Tissues Containing Au Nanoparticles. BIOSENSORS 2022; 13:bios13010008. [PMID: 36671844 PMCID: PMC9855978 DOI: 10.3390/bios13010008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 12/09/2022] [Accepted: 12/13/2022] [Indexed: 05/27/2023]
Abstract
We report non-contact laser-based Brillouin light-scattering (BLS) spectroscopy measurements of the viscoelastic properties of hyperthermally radiofrequency (RF)-heated and ablated bovine liver and chicken flesh tissues with embedded gold nanoparticles (AuNPs). The spatial lateral profile of the local surface temperature in the flesh samples during their hyperthermia was measured through optical backscattering reflectometry (OBR) using Mg−silica-NP-doped sensing fibers distributed with an RF applicator and correlated with viscoelastic variations in heat-affected and ablated tissues. Substantial changes in the tissue stiffness after heating and ablation were directly related to their heat-induced structural modifications. The main proteins responsible for muscle elasticity were denatured and irreversibly aggregated during the RF ablation. At T > 100 °C, the proteins constituting the flesh further shrank and became disorganized, leading to substantial plastic deformation of biotissues. Their uniform destruction with larger thermal lesions and a more viscoelastic network was attained via AuNP-mediated RF hyperthermal ablation. The results demonstrated here pave the way for simultaneous real-time hybrid optical sensing of viscoelasticity and local temperature in biotissues during their denaturation and gelation during hyperthermia for future applications that involve mechanical- and thermal-property-controlled theranostics.
Collapse
Affiliation(s)
- Bayan Kurbanova
- Department of Physics, School of Sciences and Humanities, Nazarbayev University, Astana 010000, Kazakhstan
| | - Zhannat Ashikbayeva
- School of Engineering and Digital Sciences, Nazarbayev University, Astana 010000, Kazakhstan
| | - Aida Amantayeva
- School of Engineering and Digital Sciences, Nazarbayev University, Astana 010000, Kazakhstan
| | - Akbota Sametova
- School of Engineering and Digital Sciences, Nazarbayev University, Astana 010000, Kazakhstan
| | - Wilfried Blanc
- Université Côte d’Azur, INPHYNI, CNRS UMR7010, Avenue Joseph Vallot, 06108 Nice, France
| | - Abduzhappar Gaipov
- Department of Medicine, Nazarbayev University School of Medicine, Astana 010000, Kazakhstan
| | - Daniele Tosi
- School of Engineering and Digital Sciences, Nazarbayev University, Astana 010000, Kazakhstan
- National Laboratory Astana, Laboratory of Biosensors and Bioinstruments, Astana 010000, Kazakhstan
| | - Zhandos Utegulov
- Department of Physics, School of Sciences and Humanities, Nazarbayev University, Astana 010000, Kazakhstan
| |
Collapse
|
20
|
Techniques for In Vivo Assessment of Corneal Biomechanics: Brillouin Spectroscopy and Hydration State - Quo Vadis? Klin Monbl Augenheilkd 2022; 239:1427-1432. [PMID: 35977709 DOI: 10.1055/a-1926-5249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
To assess the structural integrity of the cornea, non-invasive methods are needed for the local measurement of its mechanical properties. Among a number of established techniques and their associated advantages and disadvantages, Brillouin spectroscopy is still a relatively new technique, capable of determining the compressive modulus of biological tissue, specifically the cornea, in vivo. In the present paper, these various existing and developing technologies for corneal biomechanics are discussed and correlated.
Collapse
|
21
|
Comprehensive single-shot biophysical cytometry using simultaneous quantitative phase imaging and Brillouin spectroscopy. Sci Rep 2022; 12:18285. [PMID: 36316372 PMCID: PMC9622723 DOI: 10.1038/s41598-022-23049-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 10/25/2022] [Indexed: 11/06/2022] Open
Abstract
Single-cell analysis, or cytometry, is a ubiquitous tool in the biomedical sciences. Whereas most cytometers use fluorescent probes to ascertain the presence or absence of targeted molecules, biophysical parameters such as the cell density, refractive index, and viscosity are difficult to obtain. In this work, we combine two complementary techniques-quantitative phase imaging and Brillouin spectroscopy-into a label-free image cytometry platform capable of measuring more than a dozen biophysical properties of individual cells simultaneously. Using a geometric simplification linked to freshly plated cells, we can acquire the cellular diameter, volume, refractive index, mass density, non-aqueous mass, fluid volume, dry volume, the fractional water content of cells, both by mass and by volume, the Brillouin shift, Brillouin linewidth, longitudinal modulus, longitudinal viscosity, the loss modulus, and the loss tangent, all from a single acquisition, and with no assumptions of underlying parameters. Our methods are validated across three cell populations, including a control population of CHO-K1 cells, cells exposed to tubulin-disrupting nocodazole, and cells under hypoosmotic shock. Our system will unlock new avenues of research in biophysics, cell biology, and medicine.
Collapse
|
22
|
Liu L, Simon M, Muggiolu G, Vilotte F, Antoine M, Caron J, Kantor G, Barberet P, Seznec H, Audoin B. Changes in intra-nuclear mechanics in response to DNA damaging agents revealed by time-domain Brillouin micro-spectroscopy. PHOTOACOUSTICS 2022; 27:100385. [PMID: 36068801 PMCID: PMC9441258 DOI: 10.1016/j.pacs.2022.100385] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 07/05/2022] [Accepted: 07/08/2022] [Indexed: 05/25/2023]
Abstract
How DNA damage and repair processes affect the biomechanical properties of the nucleus interior remains unknown. Here, an opto-acoustic microscope based on time-domain Brillouin spectroscopy (TDBS) was used to investigate the induced regulation of intra-nuclear mechanics. With this ultrafast pump-probe technique, coherent acoustic phonons were tracked along their propagation in the intra-nucleus nanostructure and the complex stiffness moduli and thicknesses were measured with an optical resolution. Osteosarcoma cells were exposed to methyl methanesulfonate (MMS) and the presence of DNA damage was tested using immunodetection targeted against damage signaling proteins. TDBS revealed that the intra-nuclear storage modulus decreased significantly upon exposure to MMS, as a result of the chromatin decondensation and reorganization that favors molecular diffusion within the organelle. When the damaging agent was removed and cells incubated for 2 h in the buffer solution before fixation the intra-nuclear reorganization led to an inverse evolution of the storage modulus, the nucleus stiffened. The same tendency was measured when DNA double-strand breaks were caused by cell exposure to ionizing radiation. TDBS microscopy also revealed changes in acoustic dissipation, another mechanical probe of the intra-nucleus organization at the nano-scale, and changes in nucleus thickness during exposure to MMS and after recovery.
Collapse
Affiliation(s)
- Liwang Liu
- Univ. Bordeaux, CNRS, I2M, UMR 5295, F-33400 Talence, France
| | - Marina Simon
- Univ. Bordeaux, CNRS, CENBG, UMR 5797, F-33170 Gradignan, France
| | | | - Florent Vilotte
- Univ. Bordeaux, CNRS, CENBG, UMR 5797, F-33170 Gradignan, France
- Department of Radiotherapy, Institut Bergonié, Comprehensive Regional Cancer Centre of Bordeaux and Southwest and University of Bordeaux, France
| | - Mikael Antoine
- Department of Radiotherapy, Institut Bergonié, Comprehensive Regional Cancer Centre of Bordeaux and Southwest and University of Bordeaux, France
| | - Jerôme Caron
- Department of Radiotherapy, Institut Bergonié, Comprehensive Regional Cancer Centre of Bordeaux and Southwest and University of Bordeaux, France
| | - Guy Kantor
- Department of Radiotherapy, Institut Bergonié, Comprehensive Regional Cancer Centre of Bordeaux and Southwest and University of Bordeaux, France
| | | | - Hervé Seznec
- Univ. Bordeaux, CNRS, CENBG, UMR 5797, F-33170 Gradignan, France
| | - Bertrand Audoin
- Univ. Bordeaux, CNRS, I2M, UMR 5295, F-33400 Talence, France
| |
Collapse
|
23
|
Rix J, Uckermann O, Kirsche K, Schackert G, Koch E, Kirsch M, Galli R. Correlation of biomechanics and cancer cell phenotype by combined Brillouin and Raman spectroscopy of U87-MG glioblastoma cells. JOURNAL OF THE ROYAL SOCIETY, INTERFACE 2022; 19:20220209. [PMID: 35857926 DOI: 10.1098/rsif.2022.0209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The elucidation of biomechanics furthers our understanding of brain tumour biology. Brillouin spectroscopy is a new optical method that addresses viscoelastic properties down to subcellular resolution in a contact-free manner. Moreover, it can be combined with Raman spectroscopy to obtain co-localized biochemical information. Here, we applied co-registered Brillouin and Raman spectroscopy to U87-MG human glioblastoma cells in vitro. Using two-dimensional and three-dimensional cultures, we related biomechanical properties to local biochemical composition at the subcellular level, as well as the cell phenotype. Brillouin and Raman mapping of adherent cells showed that the nucleus and nucleoli are stiffer than the perinuclear region and the cytoplasm. The biomechanics of the cell cytoplasm is affected by culturing conditions, i.e. cells grown as spheroids are stiffer than adherent cells. Inside the spheroids, the presence of lipid droplets as assessed by Raman spectroscopy revealed higher Brillouin shifts that are not related to a local increase in stiffness, but are due to a higher refractive index combined with a lower mass density. This highlights the importance of locally defined biochemical reference data for a correct interpretation of the Brillouin shift of cells and tissues in future studies investigating the biomechanics of brain tumour models by Brillouin spectroscopy.
Collapse
Affiliation(s)
- Jan Rix
- Clinical Sensoring and Monitoring, Department of Anesthesiology and Intensive Care Medicine, Faculty of Medicine Carl Gustav Carus, TU Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany
| | - Ortrud Uckermann
- Neurosurgery, Faculty of Medicine Carl Gustav Carus, TU Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany.,Division of Medical Biology, Department of Psychiatry, Faculty of Medicine and University Hospital Carl Gustav Carus, TU Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany
| | - Katrin Kirsche
- Neurosurgery, Faculty of Medicine Carl Gustav Carus, TU Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany
| | - Gabriele Schackert
- Neurosurgery, Faculty of Medicine Carl Gustav Carus, TU Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany
| | - Edmund Koch
- Clinical Sensoring and Monitoring, Department of Anesthesiology and Intensive Care Medicine, Faculty of Medicine Carl Gustav Carus, TU Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany
| | - Matthias Kirsch
- Neurosurgery, Faculty of Medicine Carl Gustav Carus, TU Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany.,Klinik für Neurochirurgie, Asklepios Kliniken Schildautal, Karl-Herold-Strasse 1, D-38723 Seesen, Germany.,National Center for Tumor Diseases (NCT), Partner Site Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany
| | - Roberta Galli
- Department of Medical Physics and Biomedical Engineering, Faculty of Medicine Carl Gustav Carus, TU Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany
| |
Collapse
|
24
|
Vakhrusheva A, Murashko A, Trifonova E, Efremov Y, Timashev P, Sokolova O. Role of Actin-binding Proteins in the Regulation of Cellular Mechanics. Eur J Cell Biol 2022; 101:151241. [DOI: 10.1016/j.ejcb.2022.151241] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 04/18/2022] [Accepted: 05/19/2022] [Indexed: 12/25/2022] Open
|
25
|
Brenna C, Simioni C, Varano G, Conti I, Costanzi E, Melloni M, Neri LM. Optical tissue clearing associated with 3D imaging: application in preclinical and clinical studies. Histochem Cell Biol 2022; 157:497-511. [PMID: 35235045 PMCID: PMC9114043 DOI: 10.1007/s00418-022-02081-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/28/2022] [Indexed: 12/23/2022]
Abstract
Understanding the inner morphology of intact tissues is one of the most competitive challenges in modern biology. Since the beginning of the twentieth century, optical tissue clearing (OTC) has provided solutions for volumetric imaging, allowing the microscopic visualization of thick sections of tissue, organoids, up to whole organs and organisms (for example, mouse or rat). Recently, tissue clearing has also been introduced in clinical settings to achieve a more accurate diagnosis with the support of 3D imaging. This review aims to give an overview of the most recent developments in OTC and 3D imaging and to illustrate their role in the field of medical diagnosis, with a specific focus on clinical applications.
Collapse
Affiliation(s)
- Cinzia Brenna
- Department of Translational Medicine, University of Ferrara, 44121, Ferrara, Italy.,Medical Research Center, Medical Faculty Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany
| | - Carolina Simioni
- Department of Life Sciences and Biotechnology, University of Ferrara, 44121, Ferrara, Italy.,LTTA - Electron Microscopy Center, University of Ferrara, 44121, Ferrara, Italy
| | - Gabriele Varano
- Department of Translational Medicine, University of Ferrara, 44121, Ferrara, Italy
| | - Ilaria Conti
- Department of Translational Medicine, University of Ferrara, 44121, Ferrara, Italy
| | - Eva Costanzi
- Department of Translational Medicine, University of Ferrara, 44121, Ferrara, Italy
| | - Mattia Melloni
- Department of Translational Medicine, University of Ferrara, 44121, Ferrara, Italy
| | - Luca Maria Neri
- Department of Translational Medicine, University of Ferrara, 44121, Ferrara, Italy. .,LTTA - Electron Microscopy Center, University of Ferrara, 44121, Ferrara, Italy.
| |
Collapse
|
26
|
Carvalho E, Morais M, Ferreira H, Silva M, Guimarães S, Pêgo A. A paradigm shift: Bioengineering meets mechanobiology towards overcoming remyelination failure. Biomaterials 2022; 283:121427. [DOI: 10.1016/j.biomaterials.2022.121427] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 01/31/2022] [Accepted: 02/17/2022] [Indexed: 12/14/2022]
|
27
|
Efremov YM, Suter DM, Timashev PS, Raman A. 3D nanomechanical mapping of subcellular and sub-nuclear structures of living cells by multi-harmonic AFM with long-tip microcantilevers. Sci Rep 2022; 12:529. [PMID: 35017598 PMCID: PMC8752865 DOI: 10.1038/s41598-021-04443-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Accepted: 12/17/2021] [Indexed: 11/16/2022] Open
Abstract
Recent developments such as multi-harmonic Atomic Force Microscopy (AFM) techniques have enabled fast, quantitative mapping of nanomechanical properties of living cells. Due to their high spatiotemporal resolution, these methods provide new insights into changes of mechanical properties of subcellular structures due to disease or drug response. Here, we propose three new improvements to significantly improve the resolution, identification, and mechanical property quantification of sub-cellular and sub-nuclear structures using multi-harmonic AFM on living cells. First, microcantilever tips are streamlined using long-carbon tips to minimize long-range hydrodynamic interactions with the cell surface, to enhance the spatial resolution of nanomechanical maps and minimize hydrodynamic artifacts. Second, simultaneous Spinning Disk Confocal Microscopy (SDC) with live-cell fluorescent markers enables the unambiguous correlation between observed heterogeneities in nanomechanical maps with subcellular structures. Third, computational approaches are then used to estimate the mechanical properties of sub-nuclear structures. Results are demonstrated on living NIH 3T3 fibroblasts and breast cancer MDA-MB-231 cells, where properties of nucleoli, a deep intracellular structure, were assessed. The integrated approach opens the door to study the mechanobiology of sub-cellular structures during disease or drug response.
Collapse
Affiliation(s)
- Yuri M Efremov
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, USA
- Birck Nanotechnology Center, Purdue University, West Lafayette, IN, USA
- Institute for Regenerative Medicine, Sechenov University, Moscow, Russia
- World-Class Research Center "Digital Biodesign and Personalized Healthcare, Moscow, Russia
| | - Daniel M Suter
- Birck Nanotechnology Center, Purdue University, West Lafayette, IN, USA
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
- Bindley Bioscience Center, Purdue University, West Lafayette, IN, USA
- Purdue Institute for Integrative Neuroscience, West Lafayette, IN, USA
| | - Peter S Timashev
- Institute for Regenerative Medicine, Sechenov University, Moscow, Russia
- World-Class Research Center "Digital Biodesign and Personalized Healthcare, Moscow, Russia
- Chemistry Department, Lomonosov Moscow State University, Moscow, Russia
| | - Arvind Raman
- School of Mechanical Engineering, Purdue University, West Lafayette, IN, USA.
- Birck Nanotechnology Center, Purdue University, West Lafayette, IN, USA.
| |
Collapse
|
28
|
Schlüßler R, Kim K, Nötzel M, Taubenberger A, Abuhattum S, Beck T, Müller P, Maharana S, Cojoc G, Girardo S, Hermann A, Alberti S, Guck J. Correlative all-optical quantification of mass density and mechanics of subcellular compartments with fluorescence specificity. eLife 2022; 11:e68490. [PMID: 35001870 PMCID: PMC8816383 DOI: 10.7554/elife.68490] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 01/08/2022] [Indexed: 01/06/2023] Open
Abstract
Quantitative measurements of physical parameters become increasingly important for understanding biological processes. Brillouin microscopy (BM) has recently emerged as one technique providing the 3D distribution of viscoelastic properties inside biological samples - so far relying on the implicit assumption that refractive index (RI) and density can be neglected. Here, we present a novel method (FOB microscopy) combining BM with optical diffraction tomography and epifluorescence imaging for explicitly measuring the Brillouin shift, RI, and absolute density with specificity to fluorescently labeled structures. We show that neglecting the RI and density might lead to erroneous conclusions. Investigating the nucleoplasm of wild-type HeLa cells, we find that it has lower density but higher longitudinal modulus than the cytoplasm. Thus, the longitudinal modulus is not merely sensitive to the water content of the sample - a postulate vividly discussed in the field. We demonstrate the further utility of FOB on various biological systems including adipocytes and intracellular membraneless compartments. FOB microscopy can provide unexpected scientific discoveries and shed quantitative light on processes such as phase separation and transition inside living cells.
Collapse
Affiliation(s)
- Raimund Schlüßler
- Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische UniversitätDresdenGermany
| | - Kyoohyun Kim
- Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische UniversitätDresdenGermany
- Max Planck Institute for the Science of Light and Max-Planck-Zentrum für Physik und MedizinErlangenGermany
| | - Martin Nötzel
- Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische UniversitätDresdenGermany
| | - Anna Taubenberger
- Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische UniversitätDresdenGermany
| | - Shada Abuhattum
- Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische UniversitätDresdenGermany
- Max Planck Institute for the Science of Light and Max-Planck-Zentrum für Physik und MedizinErlangenGermany
| | - Timon Beck
- Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische UniversitätDresdenGermany
- Max Planck Institute for the Science of Light and Max-Planck-Zentrum für Physik und MedizinErlangenGermany
| | - Paul Müller
- Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische UniversitätDresdenGermany
- Max Planck Institute for the Science of Light and Max-Planck-Zentrum für Physik und MedizinErlangenGermany
| | - Shovamaye Maharana
- Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische UniversitätDresdenGermany
- Department of Microbiology and Cell Biology, Indian Institute of ScienceBengaluruIndia
| | - Gheorghe Cojoc
- Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische UniversitätDresdenGermany
| | - Salvatore Girardo
- Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische UniversitätDresdenGermany
- Max Planck Institute for the Science of Light and Max-Planck-Zentrum für Physik und MedizinErlangenGermany
| | - Andreas Hermann
- Translational Neurodegeneration Section "Albrecht Kossel", University Rostock, and German Center for Neurodegenerative Diseases (DZNE)Rostock/GreifswaldGermany
| | - Simon Alberti
- Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische UniversitätDresdenGermany
- Physics of Life, Technische Universität DresdenDresdenGermany
| | - Jochen Guck
- Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische UniversitätDresdenGermany
- Max Planck Institute for the Science of Light and Max-Planck-Zentrum für Physik und MedizinErlangenGermany
- Physics of Life, Technische Universität DresdenDresdenGermany
| |
Collapse
|
29
|
Sirotin MA, Romodina MN, Lyubin EV, Soboleva IV, Fedyanin AA. Single-cell all-optical coherence elastography with optical tweezers. BIOMEDICAL OPTICS EXPRESS 2022; 13:14-25. [PMID: 35154850 PMCID: PMC8803033 DOI: 10.1364/boe.444813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/19/2021] [Accepted: 11/22/2021] [Indexed: 06/01/2023]
Abstract
The elastic properties of cells are important for many of their functions, however the development of label free noninvasive cellular elastography method is a challenging topic. We present a novel single-cell all-optical coherence elastography method that combines optical tweezers producing mechanical excitation on the cell membrane or organelle and phase-sensitive optical coherence microscopy measuring sample response and determining its mechanical properties. The method allows living cells imaging with a lateral resolution of 0.5 μm and an axial resolution up to 10 nm, making it possible to detect nanometer displacements of the cell organelles and to record the propagation of mechanical wave along the cell membrane in response to optical tweezers excitation. We also demonstrate applicability of the method on single living red blood cells, yeast and cancer cells. The all-optical nature of the method developed makes it a promising and easily applicable tool for studying cellular and subcellular mechanics in vivo.
Collapse
Affiliation(s)
- Maxim A. Sirotin
- Faculty of Physics, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Maria N. Romodina
- Faculty of Physics, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Evgeny V. Lyubin
- Faculty of Physics, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Irina V. Soboleva
- Faculty of Physics, Lomonosov Moscow State University, Moscow 119991, Russia
- Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Moscow 119071, Russia
| | - Andrey A. Fedyanin
- Faculty of Physics, Lomonosov Moscow State University, Moscow 119991, Russia
| |
Collapse
|
30
|
Hobson CM, Falvo MR, Superfine R. A survey of physical methods for studying nuclear mechanics and mechanobiology. APL Bioeng 2021; 5:041508. [PMID: 34849443 PMCID: PMC8604565 DOI: 10.1063/5.0068126] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 10/20/2021] [Indexed: 12/23/2022] Open
Abstract
It is increasingly appreciated that the cell nucleus is not only a home for DNA but also a complex material that resists physical deformations and dynamically responds to external mechanical cues. The molecules that confer mechanical properties to nuclei certainly contribute to laminopathies and possibly contribute to cellular mechanotransduction and physical processes in cancer such as metastasis. Studying nuclear mechanics and the downstream biochemical consequences or their modulation requires a suite of complex assays for applying, measuring, and visualizing mechanical forces across diverse length, time, and force scales. Here, we review the current methods in nuclear mechanics and mechanobiology, placing specific emphasis on each of their unique advantages and limitations. Furthermore, we explore important considerations in selecting a new methodology as are demonstrated by recent examples from the literature. We conclude by providing an outlook on the development of new methods and the judicious use of the current techniques for continued exploration into the role of nuclear mechanobiology.
Collapse
Affiliation(s)
| | - Michael R. Falvo
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Richard Superfine
- Department of Applied Physical Science, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| |
Collapse
|
31
|
Mahajan V, Beck T, Gregorczyk P, Ruland A, Alberti S, Guck J, Werner C, Schlüßler R, Taubenberger AV. Mapping Tumor Spheroid Mechanics in Dependence of 3D Microenvironment Stiffness and Degradability by Brillouin Microscopy. Cancers (Basel) 2021; 13:5549. [PMID: 34771711 PMCID: PMC8583550 DOI: 10.3390/cancers13215549] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 11/02/2021] [Accepted: 11/03/2021] [Indexed: 12/14/2022] Open
Abstract
Altered biophysical properties of cancer cells and of their microenvironment contribute to cancer progression. While the relationship between microenvironmental stiffness and cancer cell mechanical properties and responses has been previously studied using two-dimensional (2D) systems, much less is known about it in a physiologically more relevant 3D context and in particular for multicellular systems. To investigate the influence of microenvironment stiffness on tumor spheroid mechanics, we first generated MCF-7 tumor spheroids within matrix metalloproteinase (MMP)-degradable 3D polyethylene glycol (PEG)-heparin hydrogels, where spheroids showed reduced growth in stiffer hydrogels. We then quantitatively mapped the mechanical properties of tumor spheroids in situ using Brillouin microscopy. Maps acquired for tumor spheroids grown within stiff hydrogels showed elevated Brillouin frequency shifts (hence increased longitudinal elastic moduli) with increasing hydrogel stiffness. Maps furthermore revealed spatial variations of the mechanical properties across the spheroids' cross-sections. When hydrogel degradability was blocked, comparable Brillouin frequency shifts of the MCF-7 spheroids were found in both compliant and stiff hydrogels, along with similar levels of growth-induced compressive stress. Under low compressive stress, single cells or free multicellular aggregates showed consistently lower Brillouin frequency shifts compared to spheroids growing within hydrogels. Thus, the spheroids' mechanical properties were modulated by matrix stiffness and degradability as well as multicellularity, and also to the associated level of compressive stress felt by tumor spheroids. Spheroids generated from a panel of invasive breast, prostate and pancreatic cancer cell lines within degradable stiff hydrogels, showed higher Brillouin frequency shifts and less cell invasion compared to those in compliant hydrogels. Taken together, our findings contribute to a better understanding of the interplay between cancer cells and microenvironment mechanics and degradability, which is relevant to better understand cancer progression.
Collapse
Affiliation(s)
- Vaibhav Mahajan
- Center for Molecular and Cellular Bioengineering (CMCB), BIOTEC, Technische Universitaet Dresden, 01307 Dresden, Germany; (V.M.); (T.B.); (P.G.); (S.A.); (R.S.)
| | - Timon Beck
- Center for Molecular and Cellular Bioengineering (CMCB), BIOTEC, Technische Universitaet Dresden, 01307 Dresden, Germany; (V.M.); (T.B.); (P.G.); (S.A.); (R.S.)
- Max Planck Institute for the Science of Light & Max-Planck-Zentrum für Physik und Medizin, Staudtstr. 2, 91058 Erlangen, Germany;
| | - Paulina Gregorczyk
- Center for Molecular and Cellular Bioengineering (CMCB), BIOTEC, Technische Universitaet Dresden, 01307 Dresden, Germany; (V.M.); (T.B.); (P.G.); (S.A.); (R.S.)
| | - André Ruland
- Max Bergmann Center, Leibniz Institute of Polymer Research Dresden, 01069 Dresden, Germany; (A.R.); (C.W.)
| | - Simon Alberti
- Center for Molecular and Cellular Bioengineering (CMCB), BIOTEC, Technische Universitaet Dresden, 01307 Dresden, Germany; (V.M.); (T.B.); (P.G.); (S.A.); (R.S.)
| | - Jochen Guck
- Max Planck Institute for the Science of Light & Max-Planck-Zentrum für Physik und Medizin, Staudtstr. 2, 91058 Erlangen, Germany;
| | - Carsten Werner
- Max Bergmann Center, Leibniz Institute of Polymer Research Dresden, 01069 Dresden, Germany; (A.R.); (C.W.)
| | - Raimund Schlüßler
- Center for Molecular and Cellular Bioengineering (CMCB), BIOTEC, Technische Universitaet Dresden, 01307 Dresden, Germany; (V.M.); (T.B.); (P.G.); (S.A.); (R.S.)
| | - Anna Verena Taubenberger
- Center for Molecular and Cellular Bioengineering (CMCB), BIOTEC, Technische Universitaet Dresden, 01307 Dresden, Germany; (V.M.); (T.B.); (P.G.); (S.A.); (R.S.)
| |
Collapse
|
32
|
Non-contact elastography methods in mechanobiology: a point of view. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2021; 51:99-104. [PMID: 34463775 PMCID: PMC8964566 DOI: 10.1007/s00249-021-01567-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/17/2021] [Accepted: 08/20/2021] [Indexed: 02/06/2023]
Abstract
In recent decades, mechanobiology has emerged as a novel perspective in the context of basic biomedical research. It is now widely recognized that living cells respond not only to chemical stimuli (for example drugs), but they are also able to decipher mechanical cues, such as the rigidity of the underlying matrix or the presence of shear forces. Probing the viscoelastic properties of cells and their local microenvironment with sub-micrometer resolution is required to study this complex interplay and dig deeper into the mechanobiology of single cells. Current approaches to measure mechanical properties of adherent cells mainly rely on the exploitation of miniaturized indenters, to poke single cells while measuring the corresponding deformation. This method provides a neat implementation of the everyday approach to measure mechanical properties of a material, but it typically results in a very low throughput and invasive experimental protocol, poorly translatable towards three-dimensional living tissues and biological constructs. To overcome the main limitations of nanoindentation experiments, a radical paradigm change is foreseen, adopting next generation contact-less methods to measure mechanical properties of biological samples with sub-cell resolution. Here we briefly introduce the field of single cell mechanical characterization, and we concentrate on a promising high resolution optical elastography technique, Brillouin spectroscopy. This non-contact technique is rapidly emerging as a potential breakthrough innovation in biomechanics, but the application to single cells is still in its infancy.
Collapse
|
33
|
Lifting restrictions on coherence loss when characterizing non-transparent hypersonic phononic crystals. Sci Rep 2021; 11:17174. [PMID: 34433886 PMCID: PMC8387379 DOI: 10.1038/s41598-021-96663-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 08/10/2021] [Indexed: 11/09/2022] Open
Abstract
Hypersonic phononic bandgap structures confine acoustic vibrations whose wavelength is commensurate with that of light, and have been studied using either time- or frequency-domain optical spectroscopy. Pulsed pump-probe lasers are the preferred instruments for characterizing periodic multilayer stacks from common vacuum deposition techniques, but the detection mechanism requires the injected sound wave to maintain coherence during propagation. Beyond acoustic Bragg mirrors, frequency-domain studies using a tandem Fabry–Perot interferometer (TFPI) find dispersions of two- and three-dimensional phononic crystals (PnCs) even for highly disordered samples, but with the caveat that PnCs must be transparent. Here, we demonstrate a hybrid technique for overcoming the limitations that time- and frequency-domain approaches exhibit separately. Accordingly, we inject coherent phonons into a non-transparent PnC using a pulsed laser and acquire the acoustic transmission spectrum on a TFPI, where pumped appear alongside spontaneously excited (i.e. incoherent) phonons. Choosing a metallic Bragg mirror for illustration, we determine the bandgap and compare with conventional time-domain spectroscopy, finding resolution of the hybrid approach to match that of a state-of-the-art asynchronous optical sampling setup. Thus, the hybrid pump–probe technique retains key performance features of the established one and going forward will likely be preferred for disordered samples.
Collapse
|
34
|
Rioboó RJJ, Gontán N, Sanderson D, Desco M, Gómez-Gaviro MV. Brillouin Spectroscopy: From Biomedical Research to New Generation Pathology Diagnosis. Int J Mol Sci 2021; 22:8055. [PMID: 34360822 PMCID: PMC8347166 DOI: 10.3390/ijms22158055] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 07/11/2021] [Accepted: 07/23/2021] [Indexed: 01/06/2023] Open
Abstract
Brillouin spectroscopy has recently gained considerable interest within the biomedical field as an innovative tool to study mechanical properties in biology. The Brillouin effect is based on the inelastic scattering of photons caused by their interaction with thermodynamically driven acoustic modes or phonons and it is highly dependent on the material's elasticity. Therefore, Brillouin is a contactless, label-free optic approach to elastic and viscoelastic analysis that has enabled unprecedented analysis of ex vivo and in vivo mechanical behavior of several tissues with a micrometric resolution, paving the way to a promising future in clinical diagnosis. Here, we comprehensively review the different studies of this fast-moving field that have been performed up to date to provide a quick guide of the current literature. In addition, we offer a general view of Brillouin's biomedical potential to encourage its further development to reach its implementation as a feasible, cost-effective pathology diagnostic tool.
Collapse
Affiliation(s)
- Rafael J. Jiménez Rioboó
- Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Científicas (CSIC), C/Sor Juana Inés de la Cruz, 3, 28049 Madrid, Spain;
| | - Nuria Gontán
- Instituto de Investigación Sanitaria Gregorio Marañón, 28007 Madrid, Spain; (N.G.); (D.S.)
- Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III, 28911 Madrid, Spain
| | - Daniel Sanderson
- Instituto de Investigación Sanitaria Gregorio Marañón, 28007 Madrid, Spain; (N.G.); (D.S.)
- Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III, 28911 Madrid, Spain
| | - Manuel Desco
- Instituto de Investigación Sanitaria Gregorio Marañón, 28007 Madrid, Spain; (N.G.); (D.S.)
- Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III, 28911 Madrid, Spain
- Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), 28029 Madrid, Spain
- Centro Nacional de Investigaciones Cardiovasculares Carlos III, 28029 Madrid, Spain
| | - Maria Victoria Gómez-Gaviro
- Instituto de Investigación Sanitaria Gregorio Marañón, 28007 Madrid, Spain; (N.G.); (D.S.)
- Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III, 28911 Madrid, Spain
| |
Collapse
|
35
|
Reynolds N, McEvoy E, Ghosh S, Panadero Pérez JA, Neu CP, McGarry P. Image-derived modeling of nucleus strain amplification associated with chromatin heterogeneity. Biophys J 2021; 120:1323-1332. [PMID: 33675762 PMCID: PMC8105730 DOI: 10.1016/j.bpj.2021.01.040] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 12/17/2020] [Accepted: 01/22/2021] [Indexed: 12/12/2022] Open
Abstract
Beyond the critical role of cell nuclei in gene expression and DNA replication, they also have a significant influence on cell mechanosensation and migration. Nuclear stiffness can impact force transmission and, furthermore, act as a physical barrier to translocation across tight spaces. As such, it is of wide interest to accurately characterize nucleus mechanical behavior. In this study, we present a computational investigation of the in situ deformation of a heterogeneous chondrocyte nucleus. A methodology is developed to accurately reconstruct a three-dimensional finite-element model of a cell nucleus from confocal microscopy. By incorporating the reconstructed nucleus into a chondrocyte model embedded in pericellular and extracellular matrix, we explore the relationship between spatially heterogeneous nuclear DNA content, shear stiffness, and resultant shear strain. We simulate an externally applied extracellular matrix shear deformation and compute intranuclear strain distributions, which are directly compared with corresponding experimentally measured distributions. Simulations suggest that the mechanical behavior of the nucleus is highly heterogeneous, with a nonlinear relationship between experimentally measured grayscale values and corresponding local shear moduli (μn). Three distinct phases are identified within the nucleus: a low-stiffness mRNA-rich interchromatin phase (0.17 kPa ≤ μn ≤ 0.63 kPa), an intermediate-stiffness euchromatin phase (1.48 kPa ≤ μn ≤ 2.7 kPa), and a high-stiffness heterochromatin phase (3.58 kPa ≤ μn ≤ 4.0 kPa). Our simulations also indicate that disruption of the nuclear envelope associated with lamin A/C depletion significantly increases nuclear strain in regions of low DNA concentration. We further investigate a phenotypic shift of chondrocytes to fibroblast-like cells, a signature for osteoarthritic cartilage, by increasing the contractility of the actin cytoskeleton to a level associated with fibroblasts. Peak nucleus strains increase by 35% compared to control, with the nucleus becoming more ellipsoidal. Our findings may have broad implications for current understanding of how local DNA concentrations and associated strain amplification can impact cell mechanotransduction and drive cell behavior in development, migration, and tumorigenesis.
Collapse
Affiliation(s)
- Noel Reynolds
- Biomedical Engineering, National University of Ireland Galway, Galway, Ireland
| | - Eoin McEvoy
- Biomedical Engineering, National University of Ireland Galway, Galway, Ireland
| | - Soham Ghosh
- Mechanical Engineering, Colorado State University, Fort Collins, Colorado
| | | | - Corey P Neu
- Mechanical Engineering, University of Colorado Boulder, Boulder, Colorado
| | - Patrick McGarry
- Biomedical Engineering, National University of Ireland Galway, Galway, Ireland.
| |
Collapse
|
36
|
Fischer LS, Rangarajan S, Sadhanasatish T, Grashoff C. Molecular Force Measurement with Tension Sensors. Annu Rev Biophys 2021; 50:595-616. [PMID: 33710908 DOI: 10.1146/annurev-biophys-101920-064756] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The ability of cells to generate mechanical forces, but also to sense, adapt to, and respond to mechanical signals, is crucial for many developmental, postnatal homeostatic, and pathophysiological processes. However, the molecular mechanisms underlying cellular mechanotransduction have remained elusive for many decades, as techniques to visualize and quantify molecular forces across individual proteins in cells were missing. The development of genetically encoded molecular tension sensors now allows the quantification of piconewton-scale forces that act upon distinct molecules in living cells and even whole organisms. In this review, we discuss the physical principles, advantages, and limitations of this increasingly popular method. By highlighting current examples from the literature, we demonstrate how molecular tension sensors can be utilized to obtain access to previously unappreciated biophysical parameters that define the propagation of mechanical forces on molecular scales. We discuss how the methodology can be further developed and provide a perspective on how the technique could be applied to uncover entirely novel aspects of mechanobiology in the future.
Collapse
Affiliation(s)
- Lisa S Fischer
- Department of Quantitative Cell Biology, Institute of Molecular Cell Biology, University of Münster, Münster D-48149, Germany;
| | - Srishti Rangarajan
- Department of Quantitative Cell Biology, Institute of Molecular Cell Biology, University of Münster, Münster D-48149, Germany;
| | - Tanmay Sadhanasatish
- Department of Quantitative Cell Biology, Institute of Molecular Cell Biology, University of Münster, Münster D-48149, Germany;
| | - Carsten Grashoff
- Department of Quantitative Cell Biology, Institute of Molecular Cell Biology, University of Münster, Münster D-48149, Germany;
| |
Collapse
|
37
|
Zhang J, Scarcelli G. Mapping mechanical properties of biological materials via an add-on Brillouin module to confocal microscopes. Nat Protoc 2021; 16:1251-1275. [PMID: 33452504 PMCID: PMC8218248 DOI: 10.1038/s41596-020-00457-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 11/04/2020] [Indexed: 01/29/2023]
Abstract
Several techniques have been developed over the past few decades to assess the mechanical properties of biological samples, which has fueled a rapid growth in the fields of biophysics, bioengineering, and mechanobiology. In this context, Brillouin optical spectroscopy has long been known as an intriguing modality for noncontact material characterization. However, limited by speed and sample damage, it had not translated into a viable imaging modality for biomedically relevant materials. Recently, based on a novel spectroscopy strategy that substantially improves the speed of Brillouin measurement, confocal Brillouin microscopy has emerged as a unique complementary tool to traditional methods as it allows noncontact, nonperturbative, label-free measurements of material mechanical properties. The feasibility and potential of this innovative technique at both the cell and tissue level have been extensively demonstrated over the past decade. As Brillouin technology is rapidly recognized, a standard approach for building and operating Brillouin microscopes is required to facilitate the widespread adoption of this technology. In this protocol, we aim to establish a robust approach for instrumentation, and data acquisition and analysis. By carefully following this protocol, we expect that a Brillouin instrument can be built in 5-9 days by a person with basic optics knowledge and alignment experience; the data acquisition as well as postprocessing can be accomplished within 2-8 h.
Collapse
Affiliation(s)
- Jitao Zhang
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA.
| | - Giuliano Scarcelli
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA.
| |
Collapse
|
38
|
Ghosh S, Cuevas VC, Seelbinder B, Neu CP. Image-Based Elastography of Heterochromatin and Euchromatin Domains in the Deforming Cell Nucleus. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2006109. [PMID: 33448065 PMCID: PMC7869959 DOI: 10.1002/smll.202006109] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/29/2020] [Indexed: 05/21/2023]
Abstract
Chromatin of the eukaryotic cell nucleus comprises microscopically dense heterochromatin and loose euchromatin domains, each with distinct transcriptional ability and roles in cellular mechanotransduction. While recent methods are developed to characterize the mechanics of nucleus, measurement of intranuclear mechanics remains largely unknown. Here, the development of "nuclear elastography," which combines microscopic imaging and computational modeling to quantify the relative elasticity of the heterochromatin and euchromatin domains, is described. Using contracting murine embryonic cardiomyocytes, nuclear elastography reveals that the heterochromatin is almost four times stiffer than the euchromatin at peak deformation. The relative elasticity between the two domains changes rapidly during the active deformation of the cardiomyocyte in the normal physiological condition but progresses more slowly in cells cultured in a mechanically stiff environment, although the relative stiffness at peak deformation does not change. Further, it is found that the disruption of the Klarsicht, ANC-1, Syne Homology domain of the Linker of Nucleoskeleton and Cytoskeleton complex compromises the intranuclear elasticity distribution resulting in elastically similar heterochromatin and euchromatin. These results provide insight into the elastography dynamics of heterochromatin and euchromatin domains and provide a noninvasive framework to further investigate the mechanobiological function of subcellular and subnuclear domains limited only by the spatiotemporal resolution of the acquired images.
Collapse
Affiliation(s)
- Soham Ghosh
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO
| | - Victor Crespo Cuevas
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO
| | - Benjamin Seelbinder
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO
| | - Corey P. Neu
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO
| |
Collapse
|
39
|
Wu H, Zhao W, Su Y, Qiu L, Wang Y, Ni H. Divided-aperture confocal Brillouin microscopy for simultaneous high-precision topographic and mechanical mapping. OPTICS EXPRESS 2020; 28:31821-31831. [PMID: 33115147 DOI: 10.1364/oe.405458] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 09/24/2020] [Indexed: 06/11/2023]
Abstract
Confocal Brillouin microscopy (CBM) is a novel and powerful technique for providing non-contact and direct readout of the micro-mechanical properties of a material, and thus used in a broad range of applications, including biological tissue detection, cell imaging, and material characterization in manufacturing. However, conventional CBMs have not enabled high precision mechanical mapping owing to the limited depth of focus and are subject to system drift during long-term measurements. In this paper, a divided-aperture confocal Brillouin microscopy (DCBM) is proposed to improve the axial focusing capability, stability, and extinction ratio of CBM. We exploit high-sensitivity divided-aperture confocal technology to achieve an unprecedented 100-fold enhancement in the axial focusing sensitivity of the existing CBMs, reaching 5 nm, and to enhance system stability. In addition, the dark-field setup improves the extinction ratio by 20 dB. To the best of our knowledge, our method achieves the first in situ topographic imaging and mechanical mapping of the sample and provides a new approach for Brillouin scattering applications in material characterization.
Collapse
|
40
|
Aleman A, Muralidhar S, Awad AA, Åkerman J, Hanstorp D. Frequency comb enhanced Brillouin microscopy. OPTICS EXPRESS 2020; 28:29540-29552. [PMID: 33114852 DOI: 10.1364/oe.398619] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 09/03/2020] [Indexed: 06/11/2023]
Abstract
Brillouin light scattering (BLS) microscopy is a well established and powerful technique to study acoustic and magnetic excitations in the frequency domain with sub-micron spatial resolution. Many other spectroscopic techniques have benefited from the introduction of femtosecond laser sources to optically pump and stimulate the sample under investigation. In BLS microscopy, the use of femtosecond lasers as the excitation source introduces several challenges, primarily since the measured frequency shift is small and the signal levels are weak due to the low duty cycle of typical femtosecond lasers. Here we present a method to evade these challenges. A strong enhancement of the weak scattering amplitude on selected modes is observed by pumping the sample with a high repetition rate frequency comb laser source. The laser beam can be focused to the diffraction limit, providing a micron pumping area. We can thus preserve the innate high frequency and spatial resolution of BLS microscopy. Furthermore, we are able to induce a point-like source of mode-selected elementary excitations which propagate away from the pumping spot. We conclude that we have demonstrated frequency comb pumped BLS microscopy as an attractive tool for studies of ultrafast induced laser dynamics directly in the frequency domain.
Collapse
|
41
|
Gómez-Gaviro MV, Sanderson D, Ripoll J, Desco M. Biomedical Applications of Tissue Clearing and Three-Dimensional Imaging in Health and Disease. iScience 2020; 23:101432. [PMID: 32805648 PMCID: PMC7452225 DOI: 10.1016/j.isci.2020.101432] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 07/29/2020] [Accepted: 07/30/2020] [Indexed: 12/27/2022] Open
Abstract
Three-dimensional (3D) optical imaging techniques can expand our knowledge about physiological and pathological processes that cannot be fully understood with 2D approaches. Standard diagnostic tests frequently are not sufficient to unequivocally determine the presence of a pathological condition. Whole-organ optical imaging requires tissue transparency, which can be achieved by using tissue clearing procedures enabling deeper image acquisition and therefore making possible the analysis of large-scale biological tissue samples. Here, we review currently available clearing agents, methods, and their application in imaging of physiological or pathological conditions in different animal and human organs. We also compare different optical tissue clearing methods discussing their advantages and disadvantages and review the use of different 3D imaging techniques for the visualization and image acquisition of cleared tissues. The use of optical tissue clearing resources for large-scale biological tissues 3D imaging paves the way for future applications in translational and clinical research.
Collapse
Affiliation(s)
- Maria Victoria Gómez-Gaviro
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Madrid, Spain; Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Madrid, Spain.
| | - Daniel Sanderson
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain; Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Madrid, Spain
| | - Jorge Ripoll
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain; Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Madrid, Spain
| | - Manuel Desco
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain; Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Madrid, Spain; Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Madrid, Spain; Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
| |
Collapse
|
42
|
Mechanical Adaptations of Epithelial Cells on Various Protruded Convex Geometries. Cells 2020; 9:cells9061434. [PMID: 32527037 PMCID: PMC7349491 DOI: 10.3390/cells9061434] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 05/29/2020] [Accepted: 06/05/2020] [Indexed: 12/16/2022] Open
Abstract
The shape of epithelial tissue supports physiological functions of organs such as intestinal villi and corneal epithelium. Despite the mounting evidence showing the importance of geometry in tissue microenvironments, the current understanding on how it affects biophysical behaviors of cells is still elusive. Here, we cultured cells on various protruded convex structure such as triangle, square, and circle shape fabricated using two-photon laser lithography and quantitatively analyzed individual cells. Morphological data indicates that epithelial cells can sense the sharpness of the corner by showing the characteristic cell alignments, which was caused by actin contractility. Cell area was mainly influenced by surface convexity, and Rho-activation increased cell area on circle shape. Moreover, we found that intermediate filaments, vimentin, and cytokeratin 8/18, play important roles in growth and adaptation of epithelial cells by enhancing expression level on convex structure depending on the shape. In addition, microtubule building blocks, α-tubulin, was also responded on geometric structure, which indicates that intermediate filaments and microtubule can cooperatively secure mechanical stability of epithelial cells on convex surface. Altogether, the current study will expand our understanding of mechanical adaptations of cells on out-of-plane geometry.
Collapse
|
43
|
Antonacci G, Beck T, Bilenca A, Czarske J, Elsayad K, Guck J, Kim K, Krug B, Palombo F, Prevedel R, Scarcelli G. Recent progress and current opinions in Brillouin microscopy for life science applications. Biophys Rev 2020; 12:615-624. [PMID: 32458371 PMCID: PMC7311586 DOI: 10.1007/s12551-020-00701-9] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 05/07/2020] [Indexed: 12/20/2022] Open
Abstract
Many important biological functions and processes are reflected in cell and tissue mechanical properties such as elasticity and viscosity. However, current techniques used for measuring these properties have major limitations, such as that they can often not measure inside intact cells and/or require physical contact-which cells can react to and change. Brillouin light scattering offers the ability to measure mechanical properties in a non-contact and label-free manner inside of objects with high spatial resolution using light, and hence has emerged as an attractive method during the past decade. This new approach, coined "Brillouin microscopy," which integrates highly interdisciplinary concepts from physics, engineering, and mechanobiology, has led to a vibrant new community that has organized itself via a European funded (COST Action) network. Here we share our current assessment and opinion of the field, as emerged from a recent dedicated workshop. In particular, we discuss the prospects towards improved and more bio-compatible instrumentation, novel strategies to infer more accurate and quantitative mechanical measurements, as well as our current view on the biomechanical interpretation of the Brillouin spectra.
Collapse
Affiliation(s)
- Giuseppe Antonacci
- Photonics Research Group, INTEC, Ghent University-imec, 9052, Ghent, Belgium
- Present address: Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133, Milan, Italy
| | - Timon Beck
- Biotechnology Center, TU Dresden, Dresden, Germany
- Max Planck Institute for the Science of Light & Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany
| | - Alberto Bilenca
- Biomedical Engineering Department, Ben-Gurion University of the Negev, Beersheba, Israel
| | - Jürgen Czarske
- Laboratory of Measurement and Sensor System Technique, TU Dresden, Dresden, Germany
- Cluster of Excellence Physics of Life, TU Dresden, Dresden, Germany
| | - Kareem Elsayad
- Advanced Microscopy, Vienna Biocenter Core Facilities (VBCF), Vienna, Austria.
| | - Jochen Guck
- Biotechnology Center, TU Dresden, Dresden, Germany
- Max Planck Institute for the Science of Light & Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany
| | - Kyoohyun Kim
- Biotechnology Center, TU Dresden, Dresden, Germany
- Max Planck Institute for the Science of Light & Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany
| | - Benedikt Krug
- Laboratory of Measurement and Sensor System Technique, TU Dresden, Dresden, Germany
| | | | - Robert Prevedel
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany.
| | - Giuliano Scarcelli
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA
| |
Collapse
|
44
|
Caponi S, Mattana S, Mattarelli M, Alunni Cardinali M, Urbanelli L, Sagini K, Emiliani C, Fioretto D. Correlative Brillouin and Raman spectroscopy data acquired on single cells. Data Brief 2020; 29:105223. [PMID: 32090158 PMCID: PMC7026319 DOI: 10.1016/j.dib.2020.105223] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 01/24/2020] [Indexed: 12/14/2022] Open
Abstract
The distribution of chemical species and the mechanical modulation inside a single cell or tissue are of fundamental importance to characterize their physiological activity or their pathological conditions [1-4]. Here we analyse these properties by means of label free, non invasive, spectroscopic methods. In particular, we use a recently developed micro-spectrometer, which acquires simultaneously Raman and Brillouin spectra on the same point with subcellular resolution [5]. The techniques ability to analyse the chemical composition and the mechanical properties of single cells has been tested on NIH/3T3 murine fibroblast cells grown in adhesion on silicon substrates. Here we report the data acquired from fixed cells after their oncogenic transformation. Mechanical and chemical evolution is evident by direct inspection of raw data. Sharing our experimental records can be valuable for researchers interested in the analysis of single cells by Raman and Brillouin spectroscopy in order: i) to compare data acquired by different set-ups and ii) to correctly model the fitting functions.
Collapse
Affiliation(s)
- Silvia Caponi
- Istituto Officina dei Materiali del CNR (CNR-IOM)—Unità di Perugia, University of Perugia, Perugia, I-06123, Italy
| | - Sara Mattana
- Department of Physics, University of Florence, Via G. Sansone 1, 50019, Sesto Fiorentino, Italy
| | - Maurizio Mattarelli
- Department of Physics and Geology, University of Perugia, Perugia, I-06123, Italy
| | | | - Lorena Urbanelli
- Department of Chemistry, Laboratory of Biochemistry and Molecular Biology, Biology and Biotechnology, University of Perugia, Via del Giochetto, Perugia, I-06123, Italy
| | - Krizia Sagini
- Department of Chemistry, Laboratory of Biochemistry and Molecular Biology, Biology and Biotechnology, University of Perugia, Via del Giochetto, Perugia, I-06123, Italy
| | - Carla Emiliani
- Department of Chemistry, Laboratory of Biochemistry and Molecular Biology, Biology and Biotechnology, University of Perugia, Via del Giochetto, Perugia, I-06123, Italy
| | - Daniele Fioretto
- Department of Physics and Geology, University of Perugia, Perugia, I-06123, Italy
| |
Collapse
|
45
|
Follain G, Herrmann D, Harlepp S, Hyenne V, Osmani N, Warren SC, Timpson P, Goetz JG. Fluids and their mechanics in tumour transit: shaping metastasis. Nat Rev Cancer 2020; 20:107-124. [PMID: 31780785 DOI: 10.1038/s41568-019-0221-x] [Citation(s) in RCA: 223] [Impact Index Per Article: 55.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/21/2019] [Indexed: 02/07/2023]
Abstract
Metastasis is a dynamic succession of events involving the dissemination of tumour cells to distant sites within the body, ultimately reducing the survival of patients with cancer. To colonize distant organs and, therefore, systemically disseminate within the organism, cancer cells and associated factors exploit several bodily fluid systems, which provide a natural transportation route. Indeed, the flow mechanics of the blood and lymphatic circulatory systems can be co-opted to improve the efficiency of cancer cell transit from the primary tumour, extravasation and metastatic seeding. Flow rates, vessel size and shear stress can all influence the survival of cancer cells in the circulation and control organotropic seeding patterns. Thus, in addition to using these fluids as a means to travel throughout the body, cancer cells exploit the underlying physical forces within these fluids to successfully seed distant metastases. In this Review, we describe how circulating tumour cells and tumour-associated factors leverage bodily fluids, their underlying forces and imposed stresses during metastasis. As the contribution of bodily fluids and their mechanics raises interesting questions about the biology of the metastatic cascade, an improved understanding of this process might provide a new avenue for targeting cancer cells in transit.
Collapse
Affiliation(s)
- Gautier Follain
- INSERM UMR_S1109, Tumor Biomechanics, Strasbourg, France
- Université de Strasbourg, Strasbourg, France
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France
| | - David Herrmann
- The Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
| | - Sébastien Harlepp
- INSERM UMR_S1109, Tumor Biomechanics, Strasbourg, France
- Université de Strasbourg, Strasbourg, France
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France
| | - Vincent Hyenne
- INSERM UMR_S1109, Tumor Biomechanics, Strasbourg, France
- Université de Strasbourg, Strasbourg, France
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France
- CNRS SNC 505, Strasbourg, France
| | - Naël Osmani
- INSERM UMR_S1109, Tumor Biomechanics, Strasbourg, France
- Université de Strasbourg, Strasbourg, France
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France
| | - Sean C Warren
- The Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
- St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
| | - Paul Timpson
- The Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, New South Wales, Australia.
- St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia.
| | - Jacky G Goetz
- INSERM UMR_S1109, Tumor Biomechanics, Strasbourg, France.
- Université de Strasbourg, Strasbourg, France.
- Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France.
| |
Collapse
|
46
|
Palacios-Serrato E, Araiza-Olivera D, Jiménez-Sánchez A. Fluorescent Probe for Transmembrane Dynamics during Osmotic Effects. Anal Chem 2020; 92:3888-3895. [DOI: 10.1021/acs.analchem.9b05390] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Eva Palacios-Serrato
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior sin número, Coyoacán, Ciudad de México 04510, Mexico
| | - Daniela Araiza-Olivera
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior sin número, Coyoacán, Ciudad de México 04510, Mexico
| | - Arturo Jiménez-Sánchez
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior sin número, Coyoacán, Ciudad de México 04510, Mexico
| |
Collapse
|
47
|
Adichtchev SV, Karpegina YA, Okotrub KA, Surovtseva MA, Zykova VA, Surovtsev NV. Brillouin spectroscopy of biorelevant fluids in relation to viscosity and solute concentration. Phys Rev E 2019; 99:062410. [PMID: 31330595 DOI: 10.1103/physreve.99.062410] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Indexed: 01/11/2023]
Abstract
The measurement of intracellular viscoelastic properties by Brillouin scattering is a rapidly developing field in biophysics and medicine. Here, the Brillouin spectroscopy is applied for a number of aqueous solutions of biorelevant molecules to reveal relations between the Brillouin line parameters (frequency and width) and viscosity or solute concentration. It is found that for the majority of the studied biorelevant molecules the solute concentration governs the Brillouin frequency in a universal manner. On the other hand, the relations between the macroscopic viscosity and Brillouin peak parameters are different for different solutes. We conclude that for biological fluids the viscosity evaluation from Brillouin data needs prior knowledge about the chemical composition. This result challenges the fidelity of the indirect experimental determinations of the cellular viscosity, when small molecule solutions are used for the calibration.
Collapse
Affiliation(s)
- S V Adichtchev
- Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Yu A Karpegina
- Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - K A Okotrub
- Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - M A Surovtseva
- Research Institute of Clinical and Experimental Lymphology-Branch of Institute of Cytology and Genetics, Russian Academy of Sciences, 630060 Novosibirsk, Russia
| | - V A Zykova
- Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - N V Surovtsev
- Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk 630090, Russia
| |
Collapse
|
48
|
Amiri A, Hastert F, Stühn L, Dietz C. Structural analysis of healthy and cancerous epithelial-type breast cells by nanomechanical spectroscopy allows us to obtain peculiarities of the skeleton and junctions. NANOSCALE ADVANCES 2019; 1:4853-4862. [PMID: 36133137 PMCID: PMC9418382 DOI: 10.1039/c9na00021f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Accepted: 10/24/2019] [Indexed: 06/16/2023]
Abstract
The transition of healthy epithelial cells to carcinoma is associated with an alteration in the structure and organization of the cytoskeleton of the cells. A comparison of the mechanical properties of cancerous and healthy cells indicated a higher deformability of the cancer cells based on averaging the mechanical properties of single cells. However, the exact reason for softening of the cancerous cells compared to their counterparts remains unclear. Here, we focused on nanomechanical spectroscopy of healthy and cancerous ductal epithelial-type breast cells by means of atomic force microscopy with high lateral and depth precision. As a result, based on atomic force microscopy measurements formation of significantly fewer microtubules in cancerous cells which was observed in our study is most likely one of the main causes for the overall change in mechanical properties without any phenotypic shift. Strikingly, in a confluent layer of invasive ductal carcinoma cells, we observed the formation of cell-cell junctions that have the potential for signal transduction among neighboring cells such as desmosomes and adherens junctions. This increases the possibility of cancerous cell collaboration in malignancy, infiltration or metastasis phenomena.
Collapse
Affiliation(s)
- Anahid Amiri
- Physics of Surfaces, Institute of Materials Science, Technische Universität Darmstadt Alarich-Weiss-Str. 2 64287 Darmstadt Germany
| | - Florian Hastert
- Cell Biology and Epigenetics, Department of Biology, Technische Universität Darmstadt 64287 Darmstadt Germany
| | - Lukas Stühn
- Physics of Surfaces, Institute of Materials Science, Technische Universität Darmstadt Alarich-Weiss-Str. 2 64287 Darmstadt Germany
| | - Christian Dietz
- Physics of Surfaces, Institute of Materials Science, Technische Universität Darmstadt Alarich-Weiss-Str. 2 64287 Darmstadt Germany
| |
Collapse
|
49
|
Brillouin microscopy: an emerging tool for mechanobiology. Nat Methods 2019; 16:969-977. [PMID: 31548707 DOI: 10.1038/s41592-019-0543-3] [Citation(s) in RCA: 192] [Impact Index Per Article: 38.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 07/29/2019] [Indexed: 12/14/2022]
Abstract
The role and importance of mechanical properties of cells and tissues in cellular function, development and disease has widely been acknowledged, however standard techniques currently used to assess them exhibit intrinsic limitations. Recently, Brillouin microscopy, a type of optical elastography, has emerged as a non-destructive, label- and contact-free method that can probe the viscoelastic properties of biological samples with diffraction-limited resolution in 3D. This led to increased attention amongst the biological and medical research communities, but it also sparked debates about the interpretation and relevance of the measured physical quantities. Here, we review this emerging technology by describing the underlying biophysical principles and discussing the interpretation of Brillouin spectra arising from heterogeneous biological matter. We further elaborate on the technique's limitations, as well as its potential for gaining insights in biology, in order to guide interested researchers from various fields.
Collapse
|
50
|
Krug B, Koukourakis N, Czarske JW. Impulsive stimulated Brillouin microscopy for non-contact, fast mechanical investigations of hydrogels. OPTICS EXPRESS 2019; 27:26910-26923. [PMID: 31674562 DOI: 10.1364/oe.27.026910] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The mechanical properties of tissues and cells are increasingly recognized as an important feature for the understanding of pathological processes and as a diagnostic tool in biomedicine. Impulsive stimulated Brillouin scattering (ISBS) is promising to overcome shortcomings of other measurement methods such as invasiveness, low spatial resolution and long acquisition time. In this paper, we present for the first time ISBS measurements of hydrogels, which are model materials for biological samples. We demonstrate ISBS measurements discriminating hydrogels of different stiffness. ISBS measurements with lateral resolution close to cellular level are presented. These results underline that ISBS microscopy has a high potential for biomedical applications.
Collapse
|