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Maibohm C, Silva F, Figueiras E, Guerreiro PT, Brito M, Romero R, Crespo H, Nieder JB. SyncRGB-FLIM: synchronous fluorescence imaging of red, green and blue dyes enabled by ultra-broadband few-cycle laser excitation and fluorescence lifetime detection. BIOMEDICAL OPTICS EXPRESS 2019; 10:1891-1904. [PMID: 31086710 PMCID: PMC6484984 DOI: 10.1364/boe.10.001891] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 02/01/2019] [Accepted: 02/06/2019] [Indexed: 06/09/2023]
Abstract
We demonstrate for the first time that an ultra-broadband 7 femtosecond (fs) few-cycle laser can be used for multicolor nonlinear imaging in a single channel detection geometry, when employing a time-resolved fluorescence detection scheme. On a multi-chromophore-labelled cell sample we show that the few-cycle laser can efficiently excite the multiple chromophores over a >400 nm two-photon absorption range. By combining the few-cycle laser excitation with time-correlated single-photon counting (TCSPC) detection to record two-photon fluorescence lifetime imaging microscopy (FLIM) images, the localization of different chromophores in the cell can be identified based on their fluorescence decay properties. The novel SyncRGB-FLIM multi-color bioimaging technique opens the possibility of real-time protein-protein interaction studies, where its single-scan operation translates into reduced laser exposure of the sample, resulting in more photoprotective conditions for biological specimens.
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Affiliation(s)
- Christian Maibohm
- Department of Nanophotonics, Ultrafast Bio- and Nanophotonics Group, INL-International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga n/a, 4715-330 Braga, Portugal
| | - Francisco Silva
- Sphere Ultrafast Photonics, R. do Campo Alegre 1021, Edifício FC6, 4169-007 Porto, Portugal
| | - Edite Figueiras
- Department of Nanophotonics, Ultrafast Bio- and Nanophotonics Group, INL-International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga n/a, 4715-330 Braga, Portugal
- Present address: Fundação Champalimaud, Avenida Brasília, 1400-038 Lisboa, Portugal
| | - Paulo T. Guerreiro
- Sphere Ultrafast Photonics, R. do Campo Alegre 1021, Edifício FC6, 4169-007 Porto, Portugal
- IFIMUP-IN and Dept. of Physics and Astronomy, Faculty of Sciences, University Porto, R. do Campo Alegre 697, 4169-007 Porto, Portugal
| | - Marina Brito
- Department of Nanophotonics, Ultrafast Bio- and Nanophotonics Group, INL-International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga n/a, 4715-330 Braga, Portugal
| | - Rosa Romero
- Sphere Ultrafast Photonics, R. do Campo Alegre 1021, Edifício FC6, 4169-007 Porto, Portugal
- IFIMUP-IN and Dept. of Physics and Astronomy, Faculty of Sciences, University Porto, R. do Campo Alegre 697, 4169-007 Porto, Portugal
| | - Helder Crespo
- Sphere Ultrafast Photonics, R. do Campo Alegre 1021, Edifício FC6, 4169-007 Porto, Portugal
- IFIMUP-IN and Dept. of Physics and Astronomy, Faculty of Sciences, University Porto, R. do Campo Alegre 697, 4169-007 Porto, Portugal
| | - Jana B. Nieder
- Department of Nanophotonics, Ultrafast Bio- and Nanophotonics Group, INL-International Iberian Nanotechnology Laboratory, Av. Mestre José Veiga n/a, 4715-330 Braga, Portugal
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Voigt FF, Emaury F, Bethge P, Waldburger D, Link SM, Carta S, van der Bourg A, Helmchen F, Keller U. Multiphoton in vivo imaging with a femtosecond semiconductor disk laser. BIOMEDICAL OPTICS EXPRESS 2017; 8:3213-3231. [PMID: 28717563 PMCID: PMC5508824 DOI: 10.1364/boe.8.003213] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 05/30/2017] [Accepted: 05/30/2017] [Indexed: 05/05/2023]
Abstract
We use an ultrafast diode-pumped semiconductor disk laser (SDL) to demonstrate several applications in multiphoton microscopy. The ultrafast SDL is based on an optically pumped Vertical External Cavity Surface Emitting Laser (VECSEL) passively mode-locked with a semiconductor saturable absorber mirror (SESAM) and generates 170-fs pulses at a center wavelength of 1027 nm with a repetition rate of 1.63 GHz. We demonstrate the suitability of this laser for structural and functional multiphoton in vivo imaging in both Drosophila larvae and mice for a variety of fluorophores (including mKate2, tdTomato, Texas Red, OGB-1, and R-CaMP1.07) and for endogenous second-harmonic generation in muscle cell sarcomeres. We can demonstrate equivalent signal levels compared to a standard 80-MHz Ti:Sapphire laser when we increase the average power by a factor of 4.5 as predicted by theory. In addition, we compare the bleaching properties of both laser systems in fixed Drosophila larvae and find similar bleaching kinetics despite the large difference in pulse repetition rates. Our results highlight the great potential of ultrafast diode-pumped SDLs for creating a cost-efficient and compact alternative light source compared to standard Ti:Sapphire lasers for multiphoton imaging.
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Affiliation(s)
- Fabian F Voigt
- Laboratory of Neural Circuit Dynamics, Brain Research Institute, University of Zurich, 8057 Zürich, Switzerland
- Neuroscience Center Zurich, University of Zurich & ETH Zurich, 8057 Zürich, Switzerland
- These authors have contributed equally
| | - Florian Emaury
- Department of Physics, Institute for Quantum Electronics, ETH Zurich, 8093 Zürich, Switzerland
- These authors have contributed equally
| | - Philipp Bethge
- Laboratory of Neural Circuit Dynamics, Brain Research Institute, University of Zurich, 8057 Zürich, Switzerland
| | - Dominik Waldburger
- Department of Physics, Institute for Quantum Electronics, ETH Zurich, 8093 Zürich, Switzerland
| | - Sandro M Link
- Department of Physics, Institute for Quantum Electronics, ETH Zurich, 8093 Zürich, Switzerland
| | - Stefano Carta
- Laboratory of Neural Circuit Dynamics, Brain Research Institute, University of Zurich, 8057 Zürich, Switzerland
| | - Alexander van der Bourg
- Laboratory of Neural Circuit Dynamics, Brain Research Institute, University of Zurich, 8057 Zürich, Switzerland
| | - Fritjof Helmchen
- Laboratory of Neural Circuit Dynamics, Brain Research Institute, University of Zurich, 8057 Zürich, Switzerland
- Neuroscience Center Zurich, University of Zurich & ETH Zurich, 8057 Zürich, Switzerland
| | - Ursula Keller
- Department of Physics, Institute for Quantum Electronics, ETH Zurich, 8093 Zürich, Switzerland
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Klinger A, Krapf L, Orzekowsky-Schroeder R, Koop N, Vogel A, Hüttmann G. Intravital autofluorescence 2-photon microscopy of murine intestinal mucosa with ultra-broadband femtosecond laser pulse excitation: image quality, photodamage, and inflammation. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:116001. [PMID: 26524678 DOI: 10.1117/1.jbo.20.11.116001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 09/16/2015] [Indexed: 06/05/2023]
Abstract
Ultra-broadband excitation with ultrashort pulses may enable simultaneous excitation of multiple endogenous fluorophores in vital tissue. Imaging living gut mucosa by autofluorescence 2-photon microscopy with more than 150 nm broad excitation at an 800-nm central wavelength from a sub-10 fs titanium-sapphire (Ti:sapphire) laser with a dielectric mirror based prechirp was compared to the excitation with 220 fs pulses of a tunable Ti:sapphire laser at 730 and 800 nm wavelengths. Excitation efficiency, image quality, and photochemical damage were evaluated. At similar excitation fluxes, the same image brightness was achieved with both lasers. As expected, with ultra-broadband pulses, fluorescence from NAD(P)H, flavines, and lipoproteins was observed simultaneously. However, nonlinear photodamage apparent as hyperfluorescence with functional and structural alterations of the tissue occurred earlier when the laser power was adjusted to the same image brightness. After only a few minutes, the immigration of polymorphonuclear leucocytes into the epithelium and degranulation of these cells, a sign of inflammation, was observed. Photodamage is promoted by the higher peak irradiances and/or by nonoptimal excitation of autofluorescence at the longer wavelength. We conclude that excitation with a tunable narrow bandwidth laser is preferable to ultra-broadband excitation for autofluorescence-based 2-photon microscopy, unless the spectral phase can be controlled to optimize excitation conditions.
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Affiliation(s)
- Antje Klinger
- University of Lübeck, Institute of Anatomy, Ratzeburger Allee 160, 23562, Lübeck, Germany
| | - Lisa Krapf
- University of Lübeck, Institute of Biomedical Optics, Peter-Monnik-Weg 4, 23562, Lübeck, Germany
| | | | - Norbert Koop
- University of Lübeck, Institute of Biomedical Optics, Peter-Monnik-Weg 4, 23562, Lübeck, Germany
| | - Alfred Vogel
- University of Lübeck, Institute of Biomedical Optics, Peter-Monnik-Weg 4, 23562, Lübeck, Germany
| | - Gereon Hüttmann
- University of Lübeck, Institute of Biomedical Optics, Peter-Monnik-Weg 4, 23562, Lübeck, GermanycAirway Research Center North (ARCN), Member of the German Center for Lung Research (DZL), Germany
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Meyer T, Schmitt M, Dietzek B, Popp J. Accumulating advantages, reducing limitations: multimodal nonlinear imaging in biomedical sciences - the synergy of multiple contrast mechanisms. JOURNAL OF BIOPHOTONICS 2013; 6:887-904. [PMID: 24259267 DOI: 10.1002/jbio.201300176] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Accepted: 11/06/2013] [Indexed: 05/29/2023]
Abstract
Multimodal nonlinear microscopy has matured during the past decades to one of the key imaging modalities in life science and biomedicine due to its unique capabilities of label-free visualization of tissue structure and chemical composition, high depth penetration, intrinsic 3D sectioning, diffraction limited resolution and low phototoxicity. This review briefly summarizes first recent advances in the field regarding the methodology, e.g., contrast mechanisms and signal characteristics used for contrast generation as well as novel image processing approaches. The second part deals with technologic developments emphasizing improvements in penetration depth, imaging speed, spatial resolution and nonlinear labeling strategies. The third part focuses on recent applications in life science fundamental research and biomedical diagnostics as well as future clinical applications.
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Affiliation(s)
- Tobias Meyer
- Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller-University Jena, Helmholtzweg 4, 07743 Jena, Germany
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Lademann J, Meinke MC, Schanzer S, Richter H, Darvin ME, Haag SF, Fluhr JW, Weigmann HJ, Sterry W, Patzelt A. In vivo methods for the analysis of the penetration of topically applied substances in and through the skin barrier. Int J Cosmet Sci 2012; 34:551-9. [PMID: 22957937 DOI: 10.1111/j.1468-2494.2012.00750.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Accepted: 08/14/2012] [Indexed: 01/21/2023]
Abstract
The efficacy of a drug is characterized by its action mechanism and its ability to pass the skin barrier. In this article, different methods are discussed, which permit this penetration process to be analysed non-invasively. Providing qualitative and quantitative information, tape stripping is one of the oldest procedures for penetration studies. Although single cell layers of corneocytes are removed from the skin surface, this procedure is considered as non-invasive and is applicable exclusively to the stratum corneum. Recently, optical and spectroscopic methods have been used to investigate the penetration process. Fluorescence-labelled drugs can be easily detected in the skin by laser scanning microscopy. This method has the disadvantage that the dye labelling changes the molecular structures of the drug and consequently might influence the penetration properties. The penetration process of non-fluorescent substances can be analysed by Raman spectroscopy, electron paramagnetic resonance, CARS and multiphoton microscopic measurements. Using these methods, the concentration of the topically applied formulations in different depths of the stratum corneum can be detected by moving the laser focus from the skin surface deeper into the stratum corneum. The advantages and disadvantages of these methods will be discussed in this article.
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Affiliation(s)
- J Lademann
- Department of Dermatology, Venerology and Allergology, Center of Experimental and Applied Cutaneous Physiology-CCP, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
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Strese H, Kuck M, Benken R, Fluhr JW, Schanzer S, Richter H, Meinke MC, Beuthan J, Benderoth C, Frankowski G, Sterry W, Lademann J. Influence of finishing textile materials on the reduction of skin irritations. Skin Res Technol 2012; 19:e409-16. [PMID: 22694170 DOI: 10.1111/j.1600-0846.2012.00658.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/26/2012] [Indexed: 01/24/2023]
Abstract
BACKGROUND An increasing number of people is reported to have sensitive skin. Consequently, the development of textile materials with comfortable wearing properties has become a major interest. One method to create a pleasant sensation of textile materials on the skin is to coat them with silk proteins. This technologically complex procedure requires both optimization and control. METHODS The present study was aimed to characterize the subjective perception of different textiles and to objectively assess their influence on skin morphology with non-invasive optical techniques like optical coherence tomography (OCT), laser scanning microscopy (LSM) and optical surface profilometry (OP). Furthermore, optical methods were used to characterize surface properties of different textile fabrics. RESULTS In the present study it could be shown that optical non-invasive methods, as applied in cosmetology and dermatology are suited to characterize the structural properties of fabrics and the effects that textile materials have on the skin. Here, both unfinished textile materials and fabrics finished with silk protein coating were investigated by OCT, LSM and OP. In addition, volunteers were interviewed about their subjective sensation when these fabrics were in contact with their skin. CONCLUSION The study showed that optical methods could be applied to compare textile materials in vitro, which permit the wearing comfort to be predicted and in vivo perception on the skin.
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Affiliation(s)
- Helene Strese
- Charité - Universitätsmedizin Berlin, Department of Dermatology, Venerology and Allergology, Center of Experimental and Applied Cutaneous Physiology, Berlin, Germany
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