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Abstract
For diabetics, taking regular blood glucose measurements is crucial. However, traditional blood glucose monitoring methods are invasive and unfriendly to diabetics. Recent studies have proposed a biofluid-based glucose sensing technique that creatively combines wearable devices with noninvasive glucose monitoring technology to enhance diabetes management. This is a revolutionary advance in the diagnosis and management of diabetes, reflects the thoughtful modernization of medicine, and promotes the development of digital medicine. This paper reviews the research progress of noninvasive continuous blood glucose monitoring (CGM), with a focus on the biological liquids that replace blood in monitoring systems, the technical principles of continuous noninvasive glucose detection, and the output and calibration of sensor signals. In addition, the existing limits of noninvasive CGM systems and prospects for the future are discussed. This work serves as a resource for further promoting the development of noninvasive CGM systems.
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Affiliation(s)
- Yilin Li
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing, 100069, PR China
- Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, 100069, PR China
| | - Yueyue Chen
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing, 100069, PR China
- Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, 100069, PR China
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2
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Serebrennikova KV, Berlina AN, Sotnikov DV, Zherdev AV, Dzantiev BB. Raman Scattering-Based Biosensing: New Prospects and Opportunities. BIOSENSORS 2021; 11:512. [PMID: 34940269 PMCID: PMC8699498 DOI: 10.3390/bios11120512] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/10/2021] [Accepted: 12/11/2021] [Indexed: 05/02/2023]
Abstract
The growing interest in the development of new platforms for the application of Raman spectroscopy techniques in biosensor technologies is driven by the potential of these techniques in identifying chemical compounds, as well as structural and functional features of biomolecules. The effect of Raman scattering is a result of inelastic light scattering processes, which lead to the emission of scattered light with a different frequency associated with molecular vibrations of the identified molecule. Spontaneous Raman scattering is usually weak, resulting in complexities with the separation of weak inelastically scattered light and intense Rayleigh scattering. These limitations have led to the development of various techniques for enhancing Raman scattering, including resonance Raman spectroscopy (RRS) and nonlinear Raman spectroscopy (coherent anti-Stokes Raman spectroscopy and stimulated Raman spectroscopy). Furthermore, the discovery of the phenomenon of enhanced Raman scattering near metallic nanostructures gave impetus to the development of the surface-enhanced Raman spectroscopy (SERS) as well as its combination with resonance Raman spectroscopy and nonlinear Raman spectroscopic techniques. The combination of nonlinear and resonant optical effects with metal substrates or nanoparticles can be used to increase speed, spatial resolution, and signal amplification in Raman spectroscopy, making these techniques promising for the analysis and characterization of biological samples. This review provides the main provisions of the listed Raman techniques and the advantages and limitations present when applied to life sciences research. The recent advances in SERS and SERS-combined techniques are summarized, such as SERRS, SE-CARS, and SE-SRS for bioimaging and the biosensing of molecules, which form the basis for potential future applications of these techniques in biosensor technology. In addition, an overview is given of the main tools for success in the development of biosensors based on Raman spectroscopy techniques, which can be achieved by choosing one or a combination of the following approaches: (i) fabrication of a reproducible SERS substrate, (ii) synthesis of the SERS nanotag, and (iii) implementation of new platforms for on-site testing.
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Affiliation(s)
| | | | | | | | - Boris B. Dzantiev
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, 119071 Moscow, Russia; (K.V.S.); (A.N.B.); (D.V.S.); (A.V.Z.)
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3
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Pence IJ, Evans CL. Translational biophotonics with Raman imaging: clinical applications and beyond. Analyst 2021; 146:6379-6393. [PMID: 34596653 PMCID: PMC8543123 DOI: 10.1039/d1an00954k] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 08/30/2021] [Indexed: 01/25/2023]
Abstract
Clinical medicine continues to seek novel rapid non-invasive tools capable of providing greater insight into disease progression and management. Raman scattering based technologies constitute a set of tools under continuing development to address outstanding challenges spanning diagnostic medicine, surgical guidance, therapeutic monitoring, and histopathology. Here we review the mechanisms and clinical applications of Raman scattering, specifically focusing on high-speed imaging methods that can provide spatial context for translational biomedical applications.
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Affiliation(s)
- Isaac J Pence
- Wellman Center for Photomedicine, Harvard Medical School, Massachusetts General Hospital, 149 13th Street, Charlestown, Massachusetts 02129, USA.
| | - Conor L Evans
- Wellman Center for Photomedicine, Harvard Medical School, Massachusetts General Hospital, 149 13th Street, Charlestown, Massachusetts 02129, USA.
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4
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Pshenay-Severin E, Bae H, Reichwald K, Matz G, Bierlich J, Kobelke J, Lorenz A, Schwuchow A, Meyer-Zedler T, Schmitt M, Messerschmidt B, Popp J. Multimodal nonlinear endomicroscopic imaging probe using a double-core double-clad fiber and focus-combining micro-optical concept. LIGHT, SCIENCE & APPLICATIONS 2021; 10:207. [PMID: 34611136 PMCID: PMC8492681 DOI: 10.1038/s41377-021-00648-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 09/06/2021] [Accepted: 09/15/2021] [Indexed: 05/05/2023]
Abstract
Multimodal non-linear microscopy combining coherent anti-Stokes Raman scattering, second harmonic generation, and two-photon excited fluorescence has proved to be a versatile and powerful tool enabling the label-free investigation of tissue structure, molecular composition, and correlation with function and disease status. For a routine medical application, the implementation of this approach into an in vivo imaging endoscope is required. However, this is a difficult task due to the requirements of a multicolour ultrashort laser delivery from a compact and robust laser source through a fiber with low losses and temporal synchronization, the efficient signal collection in epi-direction, the need for small-diameter but highly corrected endomicroobjectives of high numerical aperture and compact scanners. Here, we introduce an ultra-compact fiber-scanning endoscope platform for multimodal non-linear endomicroscopy in combination with a compact four-wave mixing based fiber laser. The heart of this fiber-scanning endoscope is an in-house custom-designed, single mode, double clad, double core pure silica fiber in combination with a 2.4 mm diameter NIR-dual-waveband corrected endomicroscopic objective of 0.55 numerical aperture and 180 µm field of view for non-linear imaging, allowing a background free, low-loss, high peak power laser delivery, and an efficient signal collection in backward direction. A linear diffractive optical grating overlays pump and Stokes laser foci across the full field of view, such that diffraction-limited performance is demonstrated for tissue imaging at one frame per second with sub-micron spatial resolution and at a high transmission of 65% from the laser to the specimen using a distal resonant fiber scanner.
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Affiliation(s)
| | - Hyeonsoo Bae
- Leibniz Institute of Photonic Technology, Member of Leibniz Health Technologies, Albert-Einstein-Str. 9, 07745, Jena, Germany
| | | | - Gregor Matz
- GRINTECH GmbH, Schillerstr. 1, 07745, Jena, Germany
| | - Jörg Bierlich
- Leibniz Institute of Photonic Technology, Member of Leibniz Health Technologies, Albert-Einstein-Str. 9, 07745, Jena, Germany
| | - Jens Kobelke
- Leibniz Institute of Photonic Technology, Member of Leibniz Health Technologies, Albert-Einstein-Str. 9, 07745, Jena, Germany
| | - Adrian Lorenz
- Leibniz Institute of Photonic Technology, Member of Leibniz Health Technologies, Albert-Einstein-Str. 9, 07745, Jena, Germany
| | - Anka Schwuchow
- Leibniz Institute of Photonic Technology, Member of Leibniz Health Technologies, Albert-Einstein-Str. 9, 07745, Jena, Germany
| | - Tobias Meyer-Zedler
- Leibniz Institute of Photonic Technology, Member of Leibniz Health Technologies, Albert-Einstein-Str. 9, 07745, Jena, Germany
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany
| | - Michael Schmitt
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany
| | | | - Juergen Popp
- Leibniz Institute of Photonic Technology, Member of Leibniz Health Technologies, Albert-Einstein-Str. 9, 07745, Jena, Germany.
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Helmholtzweg 4, 07743, Jena, Germany.
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5
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Rodríguez-Pena A, Uranga-Solchaga J, Ortiz-de-Solórzano C, Cortés-Domínguez I. Spheroscope: A custom-made miniaturized microscope for tracking tumour spheroids in microfluidic devices. Sci Rep 2020; 10:2779. [PMID: 32066786 PMCID: PMC7026415 DOI: 10.1038/s41598-020-59673-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 02/03/2020] [Indexed: 01/08/2023] Open
Abstract
3D cell culture models consisting of self-assembled tumour cells in suspension, commonly known as tumour spheroids, are becoming mainstream for high-throughput anticancer drug screening. A usual measurable outcome of screening studies is the growth rate of the spheroids in response to treatment. This is commonly quantified on images obtained using complex, expensive, optical microscopy systems, equipped with high-quality optics and customized electronics. Here we present a novel, portable, miniaturized microscope made of low-cost, mass-producible parts, which produces both fluorescence and phase-gradient contrast images. Since phase-gradient contrast imaging is based on oblique illumination, epi-illumination is used for both modalities, thus simplifying the design of the system. We describe the system, characterize its performance on synthetic samples and show proof-of-principle applications of the system consisting in imaging and monitoring the formation and growth of lung and pancreas cancer tumour spheroids within custom made microfluidic devices.
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Affiliation(s)
- A Rodríguez-Pena
- IDISNA, Ciberonc and Solid Tumours and Biomarkers Program, Center for Applied Medical Research, University of Navarra, 31008, Pamplona, Spain
| | - J Uranga-Solchaga
- USCAL, S.L. Ingeniería Mecatrónica + Dirección, Pol. Industrial Arazuri-Orcoyen, Calle C - No1, 31160, Orcoyen, Spain
| | - C Ortiz-de-Solórzano
- IDISNA, Ciberonc and Solid Tumours and Biomarkers Program, Center for Applied Medical Research, University of Navarra, 31008, Pamplona, Spain
| | - I Cortés-Domínguez
- IDISNA, Ciberonc and Solid Tumours and Biomarkers Program, Center for Applied Medical Research, University of Navarra, 31008, Pamplona, Spain.
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6
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Buttner P, Galli R, Husser D, Bollmann A. Label-free Imaging of Myocardial Remodeling in Atrial Fibrillation Using Nonlinear Optical Microscopy: A Feasibility Study. J Atr Fibrillation 2018; 10:1644. [PMID: 29988238 DOI: 10.4022/jafib.1644] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 02/23/2018] [Accepted: 02/24/2018] [Indexed: 01/21/2023]
Abstract
Atrial fibrillation, characterized by rapid disorganized electrical activation of myocardium, is caused by and accompanied by remodeling of myocardial tissue. We applied nonlinear optical microscopy (NLOM) to visualize typical myocardial features and atrial fibrillation effects in order to test anon-destructive imaging technology that in principle can be applied in vivo.Coherent anti-Stokes Raman scattering, endogenous two-photon excited fluorescence, and second harmonic generation were used to inspect unstained human atrial myocardium from three patients who underwent surgical Cox-MAZE procedure with amputation of left atrial appendage. Using NLOM techniques, we collected detailrich pictures of unstained tissue that enable comprehensive characterization of myocardial characteristics like myocyte structure, collagen and lipofuscin deposition, intercalating disc width, and fatty degradation. Development of in vivo application of the NLOM technique may represent a revolutionary approach in characterizing atrial fibrillation associated myocardial remodeling with important implications for therapy individualization and monitoring.
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Affiliation(s)
- Petra Buttner
- Department of Electrophysiology, Heart Center Leipzig, Strumpellstrabe 39, 04289 Leipzig, Germany
| | - Roberta Galli
- Clinical Sensoring and Monitoring, Department of Anesthesiology and Intensive Care Medicine, Faculty of Medicine Carl Gustav Carus, TU Dresden, Fetscherstrabe 74, 01307 Dresden, Germany
| | - Daniela Husser
- Department of Electrophysiology, Heart Center Leipzig, Strumpellstrabe 39, 04289 Leipzig, Germany
| | - Andreas Bollmann
- Department of Electrophysiology, Heart Center Leipzig, Strumpellstrabe 39, 04289 Leipzig, Germany
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7
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Weng S, Xu X, Li J, Wong STC. Combining deep learning and coherent anti-Stokes Raman scattering imaging for automated differential diagnosis of lung cancer. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:1-10. [PMID: 29086544 PMCID: PMC5661703 DOI: 10.1117/1.jbo.22.10.106017] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 10/04/2017] [Indexed: 05/05/2023]
Abstract
Lung cancer is the most prevalent type of cancer and the leading cause of cancer-related deaths worldwide. Coherent anti-Stokes Raman scattering (CARS) is capable of providing cellular-level images and resolving pathologically related features on human lung tissues. However, conventional means of analyzing CARS images requires extensive image processing, feature engineering, and human intervention. This study demonstrates the feasibility of applying a deep learning algorithm to automatically differentiate normal and cancerous lung tissue images acquired by CARS. We leverage the features learned by pretrained deep neural networks and retrain the model using CARS images as the input. We achieve 89.2% accuracy in classifying normal, small-cell carcinoma, adenocarcinoma, and squamous cell carcinoma lung images. This computational method is a step toward on-the-spot diagnosis of lung cancer and can be further strengthened by the efforts aimed at miniaturizing the CARS technique for fiber-based microendoscopic imaging.
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Affiliation(s)
- Sheng Weng
- Translational Biophotonics Laboratory, Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, Texas, United States
- Rice University, Department of Electrical and Computer Engineering, Houston, Texas, United States
| | - Xiaoyun Xu
- Translational Biophotonics Laboratory, Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, Texas, United States
| | - Jiasong Li
- Translational Biophotonics Laboratory, Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, Texas, United States
| | - Stephen T. C. Wong
- Translational Biophotonics Laboratory, Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute, Weill Cornell Medicine, Houston, Texas, United States
- Rice University, Department of Electrical and Computer Engineering, Houston, Texas, United States
- Address all correspondence to: Stephen T. C. Wong, E-mail:
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8
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Krafft C, Schmitt M, Schie IW, Cialla-May D, Matthäus C, Bocklitz T, Popp J. Markerfreie molekulare Bildgebung biologischer Zellen und Gewebe durch lineare und nichtlineare Raman-spektroskopische Ansätze. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201607604] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Christoph Krafft
- Leibniz-Institut für Photonische Technologien; Albert-Einstein-Straße 9 07745 Jena Deutschland
| | - Michael Schmitt
- Institut für Physikalische Chemie und Abbe Center of Photonics; Friedrich-Schiller-Universität Jena; Helmholtzweg 4 07743 Jena Deutschland
| | - Iwan W. Schie
- Leibniz-Institut für Photonische Technologien; Albert-Einstein-Straße 9 07745 Jena Deutschland
| | - Dana Cialla-May
- Leibniz-Institut für Photonische Technologien; Albert-Einstein-Straße 9 07745 Jena Deutschland
- Institut für Physikalische Chemie und Abbe Center of Photonics; Friedrich-Schiller-Universität Jena; Helmholtzweg 4 07743 Jena Deutschland
| | - Christian Matthäus
- Leibniz-Institut für Photonische Technologien; Albert-Einstein-Straße 9 07745 Jena Deutschland
- Institut für Physikalische Chemie und Abbe Center of Photonics; Friedrich-Schiller-Universität Jena; Helmholtzweg 4 07743 Jena Deutschland
| | - Thomas Bocklitz
- Leibniz-Institut für Photonische Technologien; Albert-Einstein-Straße 9 07745 Jena Deutschland
- Institut für Physikalische Chemie und Abbe Center of Photonics; Friedrich-Schiller-Universität Jena; Helmholtzweg 4 07743 Jena Deutschland
| | - Jürgen Popp
- Leibniz-Institut für Photonische Technologien; Albert-Einstein-Straße 9 07745 Jena Deutschland
- Institut für Physikalische Chemie und Abbe Center of Photonics; Friedrich-Schiller-Universität Jena; Helmholtzweg 4 07743 Jena Deutschland
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9
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Krafft C, Schmitt M, Schie IW, Cialla-May D, Matthäus C, Bocklitz T, Popp J. Label-Free Molecular Imaging of Biological Cells and Tissues by Linear and Nonlinear Raman Spectroscopic Approaches. Angew Chem Int Ed Engl 2017; 56:4392-4430. [PMID: 27862751 DOI: 10.1002/anie.201607604] [Citation(s) in RCA: 132] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 11/04/2016] [Indexed: 12/20/2022]
Abstract
Raman spectroscopy is an emerging technique in bioanalysis and imaging of biomaterials owing to its unique capability of generating spectroscopic fingerprints. Imaging cells and tissues by Raman microspectroscopy represents a nondestructive and label-free approach. All components of cells or tissues contribute to the Raman signals, giving rise to complex spectral signatures. Resonance Raman scattering and surface-enhanced Raman scattering can be used to enhance the signals and reduce the spectral complexity. Raman-active labels can be introduced to increase specificity and multimodality. In addition, nonlinear coherent Raman scattering methods offer higher sensitivities, which enable the rapid imaging of larger sampling areas. Finally, fiber-based imaging techniques pave the way towards in vivo applications of Raman spectroscopy. This Review summarizes the basic principles behind medical Raman imaging and its progress since 2012.
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Affiliation(s)
- Christoph Krafft
- Leibniz-Institut für Photonische Technologien, Albert-Einstein-Strasse 9, 07745, Jena, Germany
| | - Michael Schmitt
- Institut für Physikalische Chemie und Abbe Center für Photonics, Friedrich Schiller Universität Jena, Helmholtzweg 4, 07743, Jena, Germany
| | - Iwan W Schie
- Leibniz-Institut für Photonische Technologien, Albert-Einstein-Strasse 9, 07745, Jena, Germany
| | - Dana Cialla-May
- Leibniz-Institut für Photonische Technologien, Albert-Einstein-Strasse 9, 07745, Jena, Germany.,Institut für Physikalische Chemie und Abbe Center für Photonics, Friedrich Schiller Universität Jena, Helmholtzweg 4, 07743, Jena, Germany
| | - Christian Matthäus
- Leibniz-Institut für Photonische Technologien, Albert-Einstein-Strasse 9, 07745, Jena, Germany.,Institut für Physikalische Chemie und Abbe Center für Photonics, Friedrich Schiller Universität Jena, Helmholtzweg 4, 07743, Jena, Germany
| | - Thomas Bocklitz
- Leibniz-Institut für Photonische Technologien, Albert-Einstein-Strasse 9, 07745, Jena, Germany.,Institut für Physikalische Chemie und Abbe Center für Photonics, Friedrich Schiller Universität Jena, Helmholtzweg 4, 07743, Jena, Germany
| | - Jürgen Popp
- Leibniz-Institut für Photonische Technologien, Albert-Einstein-Strasse 9, 07745, Jena, Germany.,Institut für Physikalische Chemie und Abbe Center für Photonics, Friedrich Schiller Universität Jena, Helmholtzweg 4, 07743, Jena, Germany
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10
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Liao CS, Cheng JX. In Situ and In Vivo Molecular Analysis by Coherent Raman Scattering Microscopy. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2016; 9:69-93. [PMID: 27306307 PMCID: PMC5367927 DOI: 10.1146/annurev-anchem-071015-041627] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Coherent Raman scattering (CRS) microscopy is a high-speed vibrational imaging platform with the ability to visualize the chemical content of a living specimen by using molecular vibrational fingerprints. We review technical advances and biological applications of CRS microscopy. The basic theory of CRS and the state-of-the-art instrumentation of a CRS microscope are presented. We further summarize and compare the algorithms that are used to separate the Raman signal from the nonresonant background, to denoise a CRS image, and to decompose a hyperspectral CRS image into concentration maps of principal components. Important applications of single-frequency and hyperspectral CRS microscopy are highlighted. Potential directions of CRS microscopy are discussed.
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Affiliation(s)
- Chien-Sheng Liao
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana 47907;
| | - Ji-Xin Cheng
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana 47907;
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11
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Chen X, Xu X, McCormick DT, Wong K, Wong ST. Multimodal nonlinear endo-microscopy probe design for high resolution, label-free intraoperative imaging. BIOMEDICAL OPTICS EXPRESS 2015; 6. [PMID: 26203361 PMCID: PMC4505689 DOI: 10.1364/boe.6.002283] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We present a portable, multimodal, nonlinear endo-microscopy probe designed for intraoperative oncological imaging. Application of a four-wave mixing noise suppression scheme using dual wavelength wave plates (DWW) and a polarization-maintaining fiber improves tissue signal collection efficiency, allowing for miniaturization. The probe, with a small 14 mm transversal diameter, includes a customized miniaturized two-axis MEMS (micro-electromechanical system) raster scanning mirror and micro-optics with an illumination laser delivered by a polarization-maintaining fiber. The probe can potentially be integrated into the arms of a surgical robot, such as da Vinci robotic surgery system, due to its minimal cross sectional area. It has the ability to incorporate multiple imaging modalities including CARS (coherent anti-Stokes Raman scattering), SHG (second harmonic generation), and TPEF (two-photon excited fluorescence) in order to allow the surgeon to locate tumor cells within the context of normal stromal tissue. The resolution of the endo-microscope is experimentally determined to be 0.78 µm, a high level of accuracy for such a compact probe setup. The expected resolution of the as-built multimodal, nonlinear, endo-microscopy probe is 1 µm based on the calculation tolerance allocation using Monte-Carlo simulation. The reported probe is intended for use in laparoscopic or radical prostatectomy, including detection of tumor margins and avoidance of nerve impairment during surgery.
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Affiliation(s)
- Xu Chen
- Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute, Weill Cornell Medical College, Houston, Texas 77030, USA
| | - Xiaoyun Xu
- Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute, Weill Cornell Medical College, Houston, Texas 77030, USA
| | | | - Kelvin Wong
- Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute, Weill Cornell Medical College, Houston, Texas 77030, USA
- Department of Radiology, Houston Methodist Hospital, Weill Cornell Medical College, Houston, Texas 77030, USA
| | - Stephen T.C. Wong
- Department of Systems Medicine and Bioengineering, Houston Methodist Research Institute, Weill Cornell Medical College, Houston, Texas 77030, USA
- Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Weill Cornell Medical College, Houston, Texas 77030, USA
- Department of Radiology, Houston Methodist Hospital, Weill Cornell Medical College, Houston, Texas 77030, USA
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12
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Mikami H, Shiozawa M, Shirai M, Watanabe K. Compact and fully collinear light source for broadband multiplex CARS microscopy covering the fingerprint region. OPTICS EXPRESS 2015; 23:17217-17222. [PMID: 26191730 DOI: 10.1364/oe.23.017217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Compact and fully collinear light source for multiplex coherent anti-Stokes Raman scattering (CARS) microscopy was proposed and demonstrated. It consists of only a microchip laser, a short photonic crystal fiber, and a longpass filter. It offers performance of sensitivity, bandwidth, and spectral resolution suitable for biomedical applications, especially covering the entire fingerprint region (500-1800 cm(-1)). It can be readily implemented by a commercially available microchip laser and a photonic crystal fiber. It has great potential to expand the utility of CARS microscopy to a wide variety of fields such as endoscopy.
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13
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Schie IW, Krafft C, Popp J. Applications of coherent Raman scattering microscopies to clinical and biological studies. Analyst 2015; 140:3897-909. [PMID: 25811305 DOI: 10.1039/c5an00178a] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Coherent anti-Stokes Raman scattering (CARS) microscopy and stimulated Raman scattering (SRS) microscopy are two nonlinear optical imaging modalities that are at the frontier of label-free and chemical specific biological and clinical diagnostics. The applications of coherent Raman scattering (CRS) microscopies are multifold, ranging from investigation of basic aspects of cell biology to the label-free detection of pathologies. This review summarizes recent progress of biological and clinical applications of CRS between 2008 and 2014, covering applications such as lipid droplet research, single cell analysis, tissue imaging and multiphoton histopathology of atherosclerosis, myelin sheaths, skin, hair, pharmaceutics, and cancer and surgical margin detection.
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Affiliation(s)
- Iwan W Schie
- Leibniz Institute of Photonic Technology, Albert-Einstein-Straße 9, 07745 Jena, Germany.
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14
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Mikami H, Shiozawa M, Shirai M, Watanabe K. Compact light source for ultrabroadband coherent anti-Stoke Raman scattering (CARS) microscopy. OPTICS EXPRESS 2015; 23:2872-2878. [PMID: 25836148 DOI: 10.1364/oe.23.002872] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A compact light source module for ultrabroadband coherent anti-Stoke Raman scattering (CARS) microscopy was developed. It mainly consists of a nanosecond microchip laser, a photonic crystal fiber for Stokes light generation, and a single mode polarization maintaining fiber for pump light propagation. It is alignment-free and relatively low-cost compared with previous light sources of CARS microscopy. By using an assembled module, we successfully observed an ultrabroadband CARS spectrum and a CARS image of a murine adipocyte. The module is expected to greatly spread the CARS microscopy to various fields by its extreme easiness to handle.
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15
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Uckermann O, Galli R, Tamosaityte S, Leipnitz E, Geiger KD, Schackert G, Koch E, Steiner G, Kirsch M. Label-free delineation of brain tumors by coherent anti-Stokes Raman scattering microscopy in an orthotopic mouse model and human glioblastoma. PLoS One 2014; 9:e107115. [PMID: 25198698 PMCID: PMC4159970 DOI: 10.1371/journal.pone.0107115] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 08/05/2014] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Coherent anti-Stokes Raman scattering (CARS) microscopy provides fine resolution imaging and displays morphochemical properties of unstained tissue. Here, we evaluated this technique to delineate and identify brain tumors. METHODS Different human tumors (glioblastoma, brain metastases of melanoma and breast cancer) were induced in an orthotopic mouse model. Cryosections were investigated by CARS imaging tuned to probe C-H molecular vibrations, thereby addressing the lipid content of the sample. Raman microspectroscopy was used as reference. Histopathology provided information about the tumor's localization, cell proliferation and vascularization. RESULTS The morphochemical contrast of CARS images enabled identifying brain tumors irrespective of the tumor type and properties: All tumors were characterized by a lower CARS signal intensity than the normal parenchyma. On this basis, tumor borders and infiltrations could be identified with cellular resolution. Quantitative analysis revealed that the tumor-related reduction of CARS signal intensity was more pronounced in glioblastoma than in metastases. Raman spectroscopy enabled relating the CARS intensity variation to the decline of total lipid content in the tumors. The analysis of the immunohistochemical stainings revealed no correlation between tumor-induced cytological changes and the extent of CARS signal intensity reductions. The results were confirmed on samples of human glioblastoma. CONCLUSIONS CARS imaging enables label-free, rapid and objective identification of primary and secondary brain tumors. Therefore, it is a potential tool for diagnostic neuropathology as well as for intraoperative tumor delineation.
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Affiliation(s)
- Ortrud Uckermann
- Neurosurgery, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Roberta Galli
- Clinical Sensoring and Monitoring, Department of Anesthesiology and Intensive Care Medicine, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Sandra Tamosaityte
- Clinical Sensoring and Monitoring, Department of Anesthesiology and Intensive Care Medicine, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Elke Leipnitz
- Neurosurgery, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Kathrin D. Geiger
- Neuropathology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Gabriele Schackert
- Neurosurgery, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Edmund Koch
- Clinical Sensoring and Monitoring, Department of Anesthesiology and Intensive Care Medicine, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Gerald Steiner
- Clinical Sensoring and Monitoring, Department of Anesthesiology and Intensive Care Medicine, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- * E-mail: (GS); (MK)
| | - Matthias Kirsch
- Neurosurgery, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- * E-mail: (GS); (MK)
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16
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Chen SC, Choi H, So PTC, Culpepper ML. Thermomechanical Actuator-Based Three-Axis Optical Scanner for High-Speed Two-Photon Endomicroscope Imaging. JOURNAL OF MICROELECTROMECHANICAL SYSTEMS : A JOINT IEEE AND ASME PUBLICATION ON MICROSTRUCTURES, MICROACTUATORS, MICROSENSORS, AND MICROSYSTEMS 2014; 23:570-578. [PMID: 25673965 PMCID: PMC4321806 DOI: 10.1109/jmems.2013.2287708] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
This paper presents the design and characterization of a three-axis thermomechanical actuator-based endoscopic scanner for obtaining ex vivo two-photon images. The scanner consisted of two sub-systems: 1) an optical system (prism, gradient index lens, and optical fiber) that was used to deliver and collect light during imaging and 2) a small-scale silicon electromechanical scanner that could raster scan the focal point of the optics through a specimen. The scanner can be housed within a 7 mm Ø endoscope port and can scan at the speed of 3 kHz × 100 Hz × 30 Hz along three axes throughout a 125 × 125 × 100 μm3 volume. The high-speed thermomechanical actuation was achieved through the use of geometric contouring, pulsing technique, and mechanical frequency multiplication (MFM), where MFM is a new method for increasing the device cycling speed by pairing actuators of unequal forward and returning stroke speeds. Sample cross-sectional images of 15-μm fluorescent beads are presented to demonstrate the resolution and optical cross-sectioning capability of the two-photon imaging system.
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Affiliation(s)
- Shih-Chi Chen
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Hong Kong
| | - Heejin Choi
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - Peter T. C. So
- Department of Mechanical Engineering, and the Department of Biological Engineering Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - Martin L. Culpepper
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
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Yu Y, Ramachandran PV, Wang MC. Shedding new light on lipid functions with CARS and SRS microscopy. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1841:1120-9. [PMID: 24576891 DOI: 10.1016/j.bbalip.2014.02.003] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 02/12/2014] [Accepted: 02/17/2014] [Indexed: 11/19/2022]
Abstract
Modern optical microscopy has granted biomedical scientists unprecedented access to the inner workings of a cell, and revolutionized our understanding of the molecular mechanisms underlying physiological and disease states. In spite of these advances, however, visualization of certain classes of molecules (e.g. lipids) at the sub-cellular level has remained elusive. Recently developed chemical imaging modalities - Coherent Anti-Stokes Raman Scattering (CARS) microscopy and Stimulated Raman Scattering (SRS) microscopy - have helped bridge this gap. By selectively imaging the vibration of a specific chemical group, these non-invasive techniques allow high-resolution imaging of individual molecules in vivo, and circumvent the need for potentially perturbative extrinsic labels. These tools have already been applied to the study of fat metabolism, helping uncover novel regulators of lipid storage. Here we review the underlying principle of CARS and SRS microscopy, and discuss the advantages and caveats of each technique. We also review recent applications of these tools in the study of lipids as well as other biomolecules, and conclude with a brief guide for interested researchers to build and use CARS/SRS systems for their own research. This article is part of a Special Issue entitled Tools to study lipid functions.
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Affiliation(s)
- Yong Yu
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Prasanna V Ramachandran
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Meng C Wang
- Huffington Center on Aging, Baylor College of Medicine, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
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18
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Tu H, Boppart SA. Coherent anti-Stokes Raman scattering microscopy: overcoming technical barriers for clinical translation. JOURNAL OF BIOPHOTONICS 2014; 7:9-22. [PMID: 23674234 PMCID: PMC4486077 DOI: 10.1002/jbio.201300031] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 04/15/2013] [Accepted: 04/16/2013] [Indexed: 05/07/2023]
Abstract
Clinical translation of coherent anti-Stokes Raman scattering microscopy is of great interest because of the advantages of noninvasive label-free imaging, high sensitivity, and chemical specificity. For this to happen, we have identified and review the technical barriers that must be overcome. Prior investigations have developed advanced techniques (features), each of which can be used to effectively overcome one particular technical barrier. However, the implementation of one or a small number of these advanced features in previous attempts for clinical translation has often introduced more tradeoffs than benefits. In this review, we outline a strategy that would integrate multiple advanced features to overcome all the technical barriers simultaneously, effectively reduce tradeoffs, and synergistically optimize CARS microscopy for clinical translation. The operation of the envisioned system incorporates coherent Raman micro-spectroscopy for identifying vibrational biomolecular markers of disease and single-frequency (or hyperspectral) Raman imaging of these specific biomarkers for real-time in vivo diagnostics and monitoring.
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Affiliation(s)
- Haohua Tu
- Biophotonics Imaging Laboratory, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 405 North Mathews Avenue, Urbana, IL 61801, USA
| | - Stephen A. Boppart
- Biophotonics Imaging Laboratory, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 405 North Mathews Avenue, Urbana, IL 61801, USA
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19
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Mittal R, Balu M, Wilder-Smith P, Potma EO. Achromatic miniature lens system for coherent Raman scattering microscopy. BIOMEDICAL OPTICS EXPRESS 2013; 4:2196-2206. [PMID: 24156075 PMCID: PMC3799677 DOI: 10.1364/boe.4.002196] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 08/03/2013] [Accepted: 08/23/2013] [Indexed: 06/02/2023]
Abstract
We discuss the design and performance of a miniature objective lens optimized for coherent Raman scattering microscopy. The packaged lens assembly has a numerical aperture of 0.51 in water and an outer diameter of 8 mm. The lens system exhibits minimum chromatic aberrations, and produces coherent Raman scattering images with sub-micrometer lateral resolution (0.648 μm) using near-infrared excitation pulses. We demonstrate that despite the small dimensions of the miniature objective, the performance of this lens system is comparable to standard microscope objective lenses, offering opportunities for miniaturizing coherent Raman scattering imaging probes without sacrificing the image quality.
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20
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Bergner N, Medyukhina A, Geiger KD, Kirsch M, Schackert G, Krafft C, Popp J. Hyperspectral unmixing of Raman micro-images for assessment of morphological and chemical parameters in non-dried brain tumor specimens. Anal Bioanal Chem 2013; 405:8719-28. [DOI: 10.1007/s00216-013-7257-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 07/02/2013] [Accepted: 07/12/2013] [Indexed: 11/29/2022]
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21
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Smith B, Naji M, Murugkar S, Alarcon E, Brideau C, Stys P, Anis H. Portable, miniaturized, fibre delivered, multimodal CARS exoscope. OPTICS EXPRESS 2013; 21:17161-75. [PMID: 23938563 DOI: 10.1364/oe.21.017161] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We demonstrate for the first time, a portable multimodal coherent anti-Stokes Raman scattering microscope (exoscope) for minimally invasive in-vivo imaging of tissues. This device is based around a micro-electromechanical system scanning mirror and miniaturized optics with light delivery accomplished by a photonic crystal fibre. A single Ti:sapphire femtosecond pulsed laser is used as the light source to produce CARS, two photon excitation fluorescence and second harmonic generation images. The high resolution and distortion-free images obtained from various resolution and bio-samples, particularly in backward direction (epi) successfully demonstrate proof of concept, and pave the path towards future non or minimally-invasive in vivo imaging.
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Affiliation(s)
- Brett Smith
- School of Electrical Engineering and Computer Science, University of Ottawa, 800 King Edward, PO Box450 Stn A, Ottawa, Ontario K1N 6N5, Canada.
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22
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Gao L, Wang Z, Li F, Hammoudi AA, Thrall MJ, Cagle PT, Wong STC. Differential diagnosis of lung carcinoma with coherent anti-Stokes Raman scattering imaging. Arch Pathol Lab Med 2013. [PMID: 23194042 DOI: 10.5858/arpa.2012-0238-sa] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Aimed at bridging imaging technology development with cancer diagnosis, this paper first presents the prevailing challenges of lung cancer detection and diagnosis, with an emphasis on imaging techniques. It then elaborates on the working principle of coherent anti-Stokes Raman scattering microscopy, along with a description of pathologic applications to show the effectiveness and potential of this novel technology for lung cancer diagnosis. As a nonlinear optical technique probing intrinsic molecular vibrations, coherent anti-Stokes Raman scattering microscopy offers an unparalleled, label-free strategy for clinical cancer diagnosis and allows differential diagnosis of fresh specimens based on cell morphology information and patterns, without any histology staining. This powerful feature promises a higher biopsy yield for early cancer detection by incorporating a real-time imaging feed with a biopsy needle. In addition, molecularly targeted therapies would also benefit from early access to surgical specimen with high accuracy but minimum tissue consumption, therefore potentially saving specimens for follow-up diagnostic tests. Finally, we also introduce the potential of a coherent anti-Stokes Raman scattering-based endoscopy system to support intraoperative applications at the cellular level.
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Affiliation(s)
- Liang Gao
- Department of Systems Medicine and Bioengineering, The Methodist Hospital Research Institute, Houston, Texas, USA
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23
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Abstract
Conventional histopathology with hematoxylin & eosin (H&E) has been the gold standard for histopathological diagnosis of a wide range of diseases. However, it is not performed in vivo and requires thin tissue sections obtained after tissue biopsy, which carries risk, particularly in the central nervous system. Here we describe the development of an alternative, multicolored way to visualize tissue in real-time through the use of coherent Raman imaging (CRI), without the use of dyes. CRI relies on intrinsic chemical contrast based on vibrational properties of molecules and intrinsic optical sectioning by nonlinear excitation. We demonstrate that multicolor images originating from CH(2) and CH(3) vibrations of lipids and protein, as well as two-photon absorption of hemoglobin, can be obtained with subcellular resolution from fresh tissue. These stain-free histopathological images show resolutions similar to those obtained by conventional techniques, but do not require tissue fixation, sectioning or staining of the tissue analyzed.
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24
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Krafft C, Dietzek B, Schmitt M, Popp J. Raman and coherent anti-Stokes Raman scattering microspectroscopy for biomedical applications. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:040801. [PMID: 22559673 DOI: 10.1117/1.jbo.17.4.040801] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A tutorial article is presented for the use of linear and nonlinear Raman microspectroscopies in biomedical diagnostics. Coherent anti-Stokes Raman scattering (CARS) is the most frequently applied nonlinear variant of Raman spectroscopy. The basic concepts of Raman and CARS are introduced first, and subsequent biomedical applications of Raman and CARS are described. Raman microspectroscopy is applied to both in-vivo and in-vitro tissue diagnostics, and the characterization and identification of individual mammalian cells. These applications benefit from the fact that Raman spectra provide specific information on the chemical composition and molecular structure in a label-free and nondestructive manner. Combining the chemical specificity of Raman spectroscopy with the spatial resolution of an optical microscope allows recording hyperspectral images with molecular contrast. We also elaborate on interfacing Raman spectroscopic tools with other technologies such as optical tweezing, microfluidics and fiber optic probes. Thereby, we aim at presenting a guide into one exciting branch of modern biophotonics research.
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Affiliation(s)
- Christoph Krafft
- Institute of Photonic Technology Jena, Albert-Einstein-Straße 9, 07745 Jena, Germany
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25
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Bélanger E, Crépeau J, Laffray S, Vallée R, De Koninck Y, Côté D. Live animal myelin histomorphometry of the spinal cord with video-rate multimodal nonlinear microendoscopy. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:021107. [PMID: 22463025 DOI: 10.1117/1.jbo.17.2.021107] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In vivo imaging of cellular dynamics can be dramatically enabling to understand the pathophysiology of nervous system diseases. To fully exploit the power of this approach, the main challenges have been to minimize invasiveness and maximize the number of concurrent optical signals that can be combined to probe the interplay between multiple cellular processes. Label-free coherent anti-Stokes Raman scattering (CARS) microscopy, for example, can be used to follow demyelination in neurodegenerative diseases or after trauma, but myelin imaging alone is not sufficient to understand the complex sequence of events that leads to the appearance of lesions in the white matter. A commercially available microendoscope is used here to achieve minimally invasive, video-rate multimodal nonlinear imaging of cellular processes in live mouse spinal cord. The system allows for simultaneous CARS imaging of myelin sheaths and two-photon excitation fluorescence microendoscopy of microglial cells and axons. Morphometric data extraction at high spatial resolution is also described, with a technique for reducing motion-related imaging artifacts. Despite its small diameter, the microendoscope enables high speed multimodal imaging over wide areas of tissue, yet at resolution sufficient to quantify subtle differences in myelin thickness and microglial motility.
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Affiliation(s)
- Erik Bélanger
- Université Laval, Centre de recherche de l'Institut universitaire en santé mentale de Québec, Québec, Canada
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26
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Bélanger E, Henry FP, Vallée R, Randolph MA, Kochevar IE, Winograd JM, Lin CP, Côté D. In vivo evaluation of demyelination and remyelination in a nerve crush injury model. BIOMEDICAL OPTICS EXPRESS 2011; 2:2698-708. [PMID: 22091449 PMCID: PMC3184878 DOI: 10.1364/boe.2.002698] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 07/29/2011] [Accepted: 08/01/2011] [Indexed: 05/18/2023]
Abstract
Nerves of the peripheral nervous system have, to some extent, the ability to regenerate after injury, particularly in instances of crush or contusion injuries. After a controlled crush injury of the rat sciatic nerve, demyelination and remyelination are followed with functional assessments and imaged both ex vivo and in vivo over the course of 4 weeks with video-rate coherent anti-Stokes Raman scattering (CARS) microscopy. A new procedure compatible with live animal imaging is developed for performing histomorphometry of myelinated axons. This allows quantification of demyelination proximal and remyelination distal to the crush site ex vivo and in vivo respectively.
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27
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Saar BG, Johnston RS, Freudiger CW, Xie XS, Seibel EJ. Coherent Raman scanning fiber endoscopy. OPTICS LETTERS 2011; 36:2396-8. [PMID: 21725423 PMCID: PMC3164497 DOI: 10.1364/ol.36.002396] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Coherent Raman scattering methods allow for label-free imaging of tissue with chemical contrast and high spatial and temporal resolution. However, their imaging depth in scattering tissue is limited to less than 1 mm, requiring the development of endoscopes to obtain images deep inside the body. Here, we describe a coherent Raman endoscope that provides stimulated Raman scattering images at seven frames per second using a miniaturized fiber scanner, a custom-designed objective lens, and an optimized scheme for collection of scattered light from the tissue. We characterize the system and demonstrate chemical selectivity in mouse tissue images.
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Affiliation(s)
- Brian G Saar
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
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28
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Wang Z, Gao L, Luo P, Yang Y, Hammoudi AA, Wong KK, Wong STC. Coherent anti-Stokes Raman scattering microscopy imaging with suppression of four-wave mixing in optical fibers. OPTICS EXPRESS 2011; 19:7960-70. [PMID: 21643045 DOI: 10.1364/oe.19.007960] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
We demonstrated an optical fiber delivered coherent anti-Stokes Raman scattering (CARS) microscopy imaging system with a polarization-based mechanism for suppression of four-wave mixing (FWM) signals in delivery fiber. Polarization maintaining fibers (PMF) were used as the delivery fiber to ensure stability of the state of polarization (SOP) of lasers. The pump and Stokes waves were coupled into PMFs at orthogonal SOPs along the slow and fast axes of PMFs, respectively, resulting in a significant reduction of FWM signals generated in the fiber. At the output end of PMFs, a dual-wavelength waveplate was used to realign the SOPs of the two waves into identical SOPs prior to their entrance into the CARS microscope. Therefore, it allows the pump and Stokes waves with identical SOPs to excite samples at highest excitation efficiency. Our experimental results showed that this polarization-based FWM-suppressing mechanism can dramatically reduce FWM signals generated in PMFs up to approximately 99%. Meanwhile, the PMF-delivered CARS microscopy system with this mechanism can still produce high-quality CARS images. Consequently, our PMF-delivered CARS microscopy imaging system with the polarization-based FWM-suppressing mechanism potentially offers a new strategy for building fiber-based CARS endoscopes with effective suppression of FWM background noises.
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Affiliation(s)
- Zhiyong Wang
- Bioengineering and Informatics Program, The Methodist Hospital Research Institute, Weill Cornell Medical College, Houston, Texas 77030, USA.
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