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Countryman AD, Doherty CA, Herrera-Perez RM, Kasza KE. Endogenous OptoRhoGEFs reveal biophysical principles of epithelial tissue furrowing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.12.593711. [PMID: 38766210 PMCID: PMC11100791 DOI: 10.1101/2024.05.12.593711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
During development, epithelia function as malleable substrates that undergo extensive remodeling to shape developing embryos. Optogenetic control of Rho signaling provides an avenue to investigate the mechanisms of epithelial morphogenesis, but transgenic optogenetic tools can be limited by variability in tool expression levels and deleterious effects of transgenic overexpression on development. Here, we use CRISPR/Cas9 to tag Drosophila RhoGEF2 and Cysts/Dp114RhoGEF with components of the iLID/SspB optogenetic heterodimer, permitting light-dependent control over endogenous protein activities. Using quantitative optogenetic perturbations, we uncover a dose-dependence of tissue furrow depth and bending behavior on RhoGEF recruitment, revealing mechanisms by which developing embryos can shape tissues into particular morphologies. We show that at the onset of gastrulation, furrows formed by cell lateral contraction are oriented and size-constrained by a stiff basal actomyosin layer. Our findings demonstrate the use of quantitative, 3D-patterned perturbations of cell contractility to precisely shape tissue structures and interrogate developmental mechanics.
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Qiu T, Cao H, Liu K, Yu LY, Levy M, Lendaro E, Wang F, You S. Spectral-temporal-spatial customization via modulating multimodal nonlinear pulse propagation. Nat Commun 2024; 15:2031. [PMID: 38448415 PMCID: PMC10918100 DOI: 10.1038/s41467-024-46244-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Accepted: 02/20/2024] [Indexed: 03/08/2024] Open
Abstract
Multimode fibers (MMFs) are gaining renewed interest for nonlinear effects due to their high-dimensional spatiotemporal nonlinear dynamics and scalability for high power. High-brightness MMF sources with effective control of the nonlinear processes would offer possibilities in many areas from high-power fiber lasers, to bioimaging and chemical sensing, and to intriguing physics phenomena. Here we present a simple yet effective way of controlling nonlinear effects at high peak power levels. This is achieved by leveraging not only the spatial but also the temporal degrees of freedom during multimodal nonlinear pulse propagation in step-index MMFs, using a programmable fiber shaper that introduces time-dependent disorders. We achieve high tunability in MMF output fields, resulting in a broadband high-peak-power source. Its potential as a nonlinear imaging source is further demonstrated through widely tunable two-photon and three-photon microscopy. These demonstrations provide possibilities for technology advances in nonlinear optics, bioimaging, spectroscopy, optical computing, and material processing.
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Affiliation(s)
- Tong Qiu
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Honghao Cao
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Kunzan Liu
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Li-Yu Yu
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Manuel Levy
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Eva Lendaro
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Fan Wang
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Sixian You
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA.
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Zohrabi M, Lim WY, Gilinsky S, Bright VM, Gopinath JT. Adaptive aberration correction using an electrowetting array. APPLIED PHYSICS LETTERS 2023; 122:081102. [PMID: 36846091 PMCID: PMC9946697 DOI: 10.1063/5.0133473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 02/04/2023] [Indexed: 05/10/2023]
Abstract
We demonstrate a method that permits wavefront aberration correction using an array of electrowetting prisms. A fixed high fill factor microlens array followed by a lower fill factor adaptive electrowetting prism array is used to correct wavefront aberration. The design and simulation of such aberration correction mechanism is described. Our results show significant improvement to the Strehl ratio by using our aberration correction scheme which results in diffraction limited performance. Compactness and effectiveness of our design can be implemented in many applications that require aberration correction, such as microscopy and consumer electronics.
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Affiliation(s)
- Mo Zohrabi
- Department of Electrical, Computer and Energy Engineering, University of Colorado, Boulder, Colorado 80309, USA
- Author to whom correspondence should be addressed:
| | - Wei Yang Lim
- Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309, USA
| | - Samuel Gilinsky
- Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309, USA
| | - Victor M. Bright
- Department of Mechanical Engineering, University of Colorado, Boulder, Colorado 80309, USA
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Hwang HY, Baek H, Yi GC, Jho YD. Nanoscale mapping of surface strain in tapered nanorods using confocal photoluminescence spectroscopy. NANOTECHNOLOGY 2022; 33:485703. [PMID: 35998510 DOI: 10.1088/1361-6528/ac8bd9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 08/22/2022] [Indexed: 06/15/2023]
Abstract
The strain occurs spontaneously at the heterogeneous interfaces of virtually all crystalline materials. Consequently, the analysis across multiple interfaces requires a complementary characterization scheme with a resolution that fits the deformation scale. By implementing two-photon confocal laser scanning nanoscopy with an axial resolution of 10 nm, we extract the surface strain from the photoluminescence (PL) spectra, epitomized by a 2-fold enhancement at the tapered tips in comparison to the substrate of ZnO nanorods. We firstly traced the well-established contribution from quantum confinement (QC) to PL shift in three geometrically classified regions: (I) a strongly tapered region where the diameter increases from 3 to 20 nm; (II) a weakly tapered region with a gradually increasing diameter from 20 to 58 nm; (III) round cylindrical region interfacing the sapphire substrate. The measured PL shift influenced by the deformation is significantly stronger than the attained QC effect. Particularly, surface strain at the strongly tapered region turned out to drastically increase the PL shift which matches well with the analysis based on the surface to volume ratio incorporating mechanical parameters such as the compliance tensor component, strain dislocation constant, and surface stress. The surface strain increased at a lower temperature, further disclosing its inherent dependence on the thermal expansion coefficients in clear contrast to the temperature-invariant characteristics of QC.
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Affiliation(s)
- Hyeong-Yong Hwang
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford OX1 3PU, United Kingdom
| | - Hyeonjun Baek
- Department of Physics, Sogang University, Seoul 04107, Republic of Korea
| | - Gyu-Chul Yi
- Department of Physics and Astronomy, and Institute of Applied Physics, Seoul National University, Seoul 08826, Republic of Korea
| | - Young-Dahl Jho
- School of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
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Freymüller C, Ströbl S, Aumiller M, Eisel M, Sroka R, Rühm A. Development of a microstructured tissue phantom with adaptable optical properties for use with microscopes and fluorescence lifetime imaging systems. Lasers Surg Med 2022; 54:1010-1026. [PMID: 35753039 DOI: 10.1002/lsm.23556] [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: 10/28/2021] [Revised: 04/22/2022] [Accepted: 04/24/2022] [Indexed: 11/08/2022]
Abstract
OBJECTIVES For the development and validation of diagnostic procedures based on microscopic methods, knowledge about the imaging depth and achievable resolution in tissue is crucial. This poses the challenge to develop a microscopic artificial phantom focused on the microscopic instead of the macroscopic optical tissue characteristics. METHODS As existing artificial tissue phantoms designed for image forming systems are primarily targeted at wide field applications, they are unsuited for reaching the formulated objective. Therefore, a microscopy- and microendoscopy-suited artificial tissue phantom was developed and characterized. It is based on a microstructured glass surface coated with fluorescent beads at known depths covered by a scattering agent with modifiable optical properties. The phantom was examined with different kinds of microscopy systems in order to characterize its quality and stability and to demonstrate its usefulness for instrument comparison, for example, regarding structural as well as fluorescence lifetime analysis. RESULTS The analysis of the manufactured microstructured glass surfaces showed high regularity in their physical dimensions in accordance with the specifications. Measurements of the optical parameters of the scattering medium were consistent with simulations. The fluorescent beads coating proved to be stable for a respectable period of time (about a week). The developed artificial tissue phantom was successfully used to detect differences in image quality between a research microscope and an endoscopy based system. Plausible causes for the observed differences could be derived based on the well known microstructure of the phantom. CONCLUSIONS The artificial tissue phantom is well suited for the intended use with microscopic and microendoscopic systems. Due to its configurable design, it can be adapted to a wide range of applications. It is especially targeted at the characterization and calibration of clinical imaging systems that often lack extensive positioning capabilities such as an intrinsic z-stage.
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Affiliation(s)
- Christian Freymüller
- Laser-Forschungslabor, LIFE Center, Department of Urology, University Hospital, LMU Munich, Munich, Germany.,Department of Urology, University Hospital, LMU Munich, Munich, Germany
| | - Stephan Ströbl
- Laser-Forschungslabor, LIFE Center, Department of Urology, University Hospital, LMU Munich, Munich, Germany.,Department of Urology, University Hospital, LMU Munich, Munich, Germany.,Research Center for Microtechnology, FH Vorarlberg, Dornbirn, Vorarlberg, Austria
| | - Maximilian Aumiller
- Laser-Forschungslabor, LIFE Center, Department of Urology, University Hospital, LMU Munich, Munich, Germany.,Department of Urology, University Hospital, LMU Munich, Munich, Germany
| | - Maximilian Eisel
- Laser-Forschungslabor, LIFE Center, Department of Urology, University Hospital, LMU Munich, Munich, Germany.,Department of Urology, University Hospital, LMU Munich, Munich, Germany
| | - Ronald Sroka
- Laser-Forschungslabor, LIFE Center, Department of Urology, University Hospital, LMU Munich, Munich, Germany.,Department of Urology, University Hospital, LMU Munich, Munich, Germany
| | - Adrian Rühm
- Laser-Forschungslabor, LIFE Center, Department of Urology, University Hospital, LMU Munich, Munich, Germany.,Department of Urology, University Hospital, LMU Munich, Munich, Germany
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Jabermoradi A, Yang S, Gobes MI, van Duynhoven JPM, Hohlbein J. Enabling single-molecule localization microscopy in turbid food emulsions. PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A: MATHEMATICAL, PHYSICAL AND ENGINEERING SCIENCES 2022; 380:20200164. [PMID: 0 DOI: 10.1098/rsta.2020.0164] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 08/20/2021] [Indexed: 05/19/2023]
Abstract
Turbidity poses a major challenge for the microscopic characterization of food systems. Local mismatches in refractive indices, for example, lead to significant image deterioration along sample depth. To mitigate the issue of turbidity and to increase the accessible optical resolution in food microscopy, we added adaptive optics (AO) and flat-field illumination to our previously published open microscopy framework, the miCube. In the detection path, we implemented AO via a deformable mirror to compensate aberrations and to modulate the emission wavefront enabling the engineering of point spread functions (PSFs) for single-molecule localization microscopy (SMLM) in three dimensions. As a model system for a non-transparent food colloid such as mayonnaise, we designed an oil-in-water emulsion containing the ferric ion binding protein phosvitin commonly present in egg yolk. We targeted phosvitin with fluorescently labelled primary antibodies and used PSF engineering to obtain two- and three-dimensional images of phosvitin covered oil droplets with sub 100 nm resolution. Our data indicated that phosvitin is homogeneously distributed at the interface. With the possibility to obtain super-resolved images in depth, our work paves the way for localizing biomacromolecules at heterogeneous colloidal interfaces in food emulsions.
This article is part of the Theo Murphy meeting issue ‘Super-resolution structured illumination microscopy (part 2)’.
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Affiliation(s)
- Abbas Jabermoradi
- Laboratory of Biophysics, Wageningen University and Research, Stippeneng 4, Wageningen 6708, The Netherlands
| | - Suyeon Yang
- Laboratory of Biophysics, Wageningen University and Research, Stippeneng 4, Wageningen 6708, The Netherlands
| | - Martijn I. Gobes
- Laboratory of Biophysics, Wageningen University and Research, Stippeneng 4, Wageningen 6708, The Netherlands
| | - John P. M. van Duynhoven
- Laboratory of Biophysics, Wageningen University and Research, Stippeneng 4, Wageningen 6708, The Netherlands
- Unilever Global Foods Innovation Centre, Bronland 14, Wageningen 6708, The Netherlands
| | - Johannes Hohlbein
- Laboratory of Biophysics, Wageningen University and Research, Stippeneng 4, Wageningen 6708, The Netherlands
- Microspectroscopy Research Facility, Wageningen University and Research, Stippeneng 4, Wageningen 6708, The Netherlands
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7
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Peres C, Nardin C, Yang G, Mammano F. Commercially derived versatile optical architecture for two-photon STED, wavelength mixing and label-free microscopy. BIOMEDICAL OPTICS EXPRESS 2022; 13:1410-1429. [PMID: 35414982 PMCID: PMC8973165 DOI: 10.1364/boe.444525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 01/03/2022] [Accepted: 01/06/2022] [Indexed: 06/14/2023]
Abstract
Multimodal microscopy combines multiple non-linear techniques that take advantage of different optical processes to generate contrast and increase the amount of information that can be obtained from biological samples. However, the most advanced optical architectures are typically custom-made and often require on-site adjustment of optical components performed by trained personnel for optimal performance. Here, we describe a hybrid system we built based on a commercial upright microscope. We show that our multimodal imaging platform can be used to seamlessly perform two-photon STED, wavelength mixing and label-free microscopy in both ex vivo and in vivo turbid samples. The system is stable and endowed with remote alignment hardware that ensures long-term operability also for non-expert users, using the alignment protocol described in this article and in the related material. This optical architecture is an important step forward towards a wider practical applicability of non-linear optics to bioimaging.
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Affiliation(s)
- Chiara Peres
- CNR Institute of Biochemistry and Cell Biology, 00015 Monterotondo, Rome, Italy
- Department of Physics and Astronomy “G. Galilei”, University of Padova, 35131 Padova, Italy
| | - Chiara Nardin
- CNR Institute of Biochemistry and Cell Biology, 00015 Monterotondo, Rome, Italy
| | - Guang Yang
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, 201210 Shanghai, China
| | - Fabio Mammano
- CNR Institute of Biochemistry and Cell Biology, 00015 Monterotondo, Rome, Italy
- Department of Physics and Astronomy “G. Galilei”, University of Padova, 35131 Padova, Italy
- Shanghai Institute for Advanced Immunochemical Studies, ShanghaiTech University, 201210 Shanghai, China
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8
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Aragon MJ, Mok AT, Shea J, Wang M, Kim H, Barkdull N, Xu C, Yapici N. Multiphoton imaging of neural structure and activity in Drosophila through the intact cuticle. eLife 2022; 11:e69094. [PMID: 35073257 PMCID: PMC8846588 DOI: 10.7554/elife.69094] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 01/23/2022] [Indexed: 11/13/2022] Open
Abstract
We developed a multiphoton imaging method to capture neural structure and activity in behaving flies through the intact cuticle. Our measurements showed that the fly head cuticle has surprisingly high transmission at wavelengths >900nm, and the difficulty of through-cuticle imaging is due to the air sacs and/or fat tissue underneath the head cuticle. By compressing or removing the air sacs, we performed multiphoton imaging of the fly brain through the intact cuticle. Our anatomical and functional imaging results show that 2- and 3-photon imaging are comparable in superficial regions such as the mushroom body, but 3-photon imaging is superior in deeper regions such as the central complex and beyond. We further demonstrated 2-photon through-cuticle functional imaging of odor-evoked calcium responses from the mushroom body γ-lobes in behaving flies short term and long term. The through-cuticle imaging method developed here extends the time limits of in vivo imaging in flies and opens new ways to capture neural structure and activity from the fly brain.
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Affiliation(s)
- Max Jameson Aragon
- Department of Neurobiology and Behavior, Cornell UniversityIthacaUnited States
| | - Aaron T Mok
- School of Applied and Engineering Physics, Cornell UniversityIthacaUnited States
| | - Jamien Shea
- Department of Neurobiology and Behavior, Cornell UniversityIthacaUnited States
| | - Mengran Wang
- School of Applied and Engineering Physics, Cornell UniversityIthacaUnited States
| | - Haein Kim
- Department of Neurobiology and Behavior, Cornell UniversityIthacaUnited States
| | - Nathan Barkdull
- Department of Physics, University of FloridaGainesvilleUnited States
| | - Chris Xu
- School of Applied and Engineering Physics, Cornell UniversityIthacaUnited States
| | - Nilay Yapici
- Department of Neurobiology and Behavior, Cornell UniversityIthacaUnited States
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9
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Zhai X, Vyas S, Yeh JA, Luo Y. Two-photon fluorescence imaging of subsurface tissue structures with volume holographic microscopy. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:JBO-200226SSR. [PMID: 33231017 PMCID: PMC7682785 DOI: 10.1117/1.jbo.25.12.123705] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 11/06/2020] [Indexed: 06/11/2023]
Abstract
SIGNIFICANCE Two-photon (2P) fluorescence imaging can provide background-free high-contrast images from the scattering tissues. However, obtaining a multiplane image is not straightforward. We present a two-photon volume holographic imaging (2P-VHI) system for multiplane imaging. AIM Our goal was to design and implement a 2P-VHI system that can provide the high-contrast optically sectioned images at multiple planes. APPROACH A 2P-VHI system is presented that incorporates angularly multiplexed volume holographic gratings and a femtosecond laser source for fluorescence excitation for multiplane imaging. A volume hologram with multiplexed gratings provides multifocal observation, whereas nonlinear excitation using a femtosecond laser helps in significantly enhancing both depth resolution and contrast of images. RESULTS Standard fluorescent beads are used to demonstrate the imaging performance of the 2P-VHI system. Two-depth resolved optical-sectioning images of fluorescently labeled thick mice intestine samples were obtained. In addition, the optical sectioning capability of our system is measured and compared with that of a conventional VHI system. CONCLUSIONS Results demonstrated that 2P excitation in VHI systems provided the optical sectioning ability that helps in reducing background noise in the images. Integration of nonlinear fluorescence excitation in the VHI provides some unique advantages to the system and has potential to design multidepth optical sectioned spatial-spectral imaging systems.
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Affiliation(s)
- Xiaomin Zhai
- National Taiwan University, Institute of Medical Device and Imaging, Taipei, Taiwan
| | - Sunil Vyas
- National Taiwan University, Institute of Medical Device and Imaging, Taipei, Taiwan
| | - J. Andrew Yeh
- National Tsing Hua University, Department of Power Mechanical Engineering, Hsinchu, Taiwan
| | - Yuan Luo
- National Taiwan University, Institute of Medical Device and Imaging, Taipei, Taiwan
- National Taiwan University, Molecular Imaging Center, Taipei, Taiwan
- National Taiwan University, YongLin Institute of Health, Taipei, Taiwan
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10
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Medyukhina A, Figge MT. DeconvTest: Simulation framework for quantifying errors and selecting optimal parameters of image deconvolution. JOURNAL OF BIOPHOTONICS 2020; 13:e201960079. [PMID: 31957214 DOI: 10.1002/jbio.201960079] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 01/16/2020] [Accepted: 01/16/2020] [Indexed: 06/10/2023]
Abstract
Deconvolution is an essential step of image processing that aims to compensate for the image blur caused by the microscope's point spread function. With many existing deconvolution methods, it is challenging to choose the method and its parameters most appropriate for particular image data at hand. To facilitate this task, we developed DeconvTest: an open-source Python-based framework for generating synthetic microscopy images, deconvolving them with different algorithms, and quantifying reconstruction errors. In contrast to existing software, DeconvTest combines all components required to analyze deconvolution performance in a systematic, high-throughput and quantitative manner. We demonstrate the power of the framework by using it to identify the optimal deconvolution settings for synthetic and real image data. Based on this, we provide a guideline for (a) choosing optimal values of deconvolution parameters for image data at hand and (b) optimizing imaging conditions for best results in combination with subsequent image deconvolution.
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Affiliation(s)
- Anna Medyukhina
- Applied Systems Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knöll-Institute, Jena, Germany
- Center for Bioimage Informatics, St. Jude Children's Research Hospital, Memphis, TN
| | - Marc Thilo Figge
- Applied Systems Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knöll-Institute, Jena, Germany
- Institute of Microbiology, Faculty of Biological Sciences, Friedrich-Schiller-University Jena, Jena, Germany
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11
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Cheng X, Li Y, Mertz J, SakadŽić S, Devor A, Boas DA, Tian L. Development of a beam propagation method to simulate the point spread function degradation in scattering media. OPTICS LETTERS 2019; 44:4989-4992. [PMID: 31613246 PMCID: PMC6889808 DOI: 10.1364/ol.44.004989] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 09/12/2019] [Indexed: 05/23/2023]
Abstract
Scattering is one of the main issues that limit the imaging depth in deep tissue optical imaging. To characterize the role of scattering, we have developed a forward model based on the beam propagation method and established the link between the macroscopic optical properties of the media and the statistical parameters of the phase masks applied to the wavefront. Using this model, we have analyzed the degradation of the point-spread function of the illumination beam in the transition regime from ballistic to diffusive light transport. Our method provides a wave-optic simulation toolkit to analyze the effects of scattering on image quality degradation in scanning microscopy. Our open-source implementation is available at https://github.com/BUNPC/Beam-Propagation-Method.
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Affiliation(s)
- Xiaojun Cheng
- Department of Biomedical Engineering, Boston University, Massachusetts 02215, USA
- Neurophotonics Center, Boston University Massachusetts 02215, USA
| | - Yunzhe Li
- Department of Electrical and Computer Engineering, Boston University, Massachusetts 02215, USA
| | - Jerome Mertz
- Department of Biomedical Engineering, Boston University, Massachusetts 02215, USA
- Neurophotonics Center, Boston University Massachusetts 02215, USA
| | - Sava SakadŽić
- Optics Division at the Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, USA
| | - Anna Devor
- Neurophotonics Center, Boston University Massachusetts 02215, USA
- Optics Division at the Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts 02129, USA
- Departments of Neurosciences and Radiology, University of California, San Diego, California 92093, USA
| | - David A. Boas
- Department of Biomedical Engineering, Boston University, Massachusetts 02215, USA
- Neurophotonics Center, Boston University Massachusetts 02215, USA
| | - Lei Tian
- Department of Electrical and Computer Engineering, Boston University, Massachusetts 02215, USA
- Neurophotonics Center, Boston University Massachusetts 02215, USA
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12
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Hsu KJ, Lin YY, Chiang AS, Chu SW. Optical properties of adult Drosophila brains in one-, two-, and three-photon microscopy. BIOMEDICAL OPTICS EXPRESS 2019; 10:1627-1637. [PMID: 31086697 PMCID: PMC6484994 DOI: 10.1364/boe.10.001627] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 01/23/2019] [Accepted: 02/17/2019] [Indexed: 06/09/2023]
Abstract
Drosophila is widely used in connectome studies due to its small brain size, sophisticated genetic tools, and the most complete single-neuron-based anatomical brain map. Surprisingly, even the brain thickness is only 200-μm, common Ti:sapphire-based two-photon excitation cannot penetrate, possibly due to light aberration/scattering of trachea. Here we quantitatively characterized scattering and light distortion of trachea-filled tissues, and found that trachea-induced light distortion dominates at long wavelength by comparing one-photon (488-nm), two-photon (920-nm), and three-photon (1300-nm) excitations. Whole-Drosophila-brain imaging is achieved by reducing tracheal light aberration/scattering via brain-degassing or long-wavelength excitation at 1300-nm. Our work paves the way toward constructing whole-brain connectome in a living Drosophila.
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Affiliation(s)
- Kuo-Jen Hsu
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
- Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Yen-Yin Lin
- Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Ann-Shyn Chiang
- Brain Research Center, National Tsing Hua University, Hsinchu 30013, Taiwan
- Institute of Systems Neuroscience, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung 80780, Taiwan
- Kavli Institute for Brain and Mind, University of California at San Diego, La Jolla, CA 92093-0526, USA
| | - Shi-Wei Chu
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
- Molecular Imaging Center, National Taiwan University, Taipei 10617, Taiwan
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13
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Contributions of the glycocalyx, endothelium, and extravascular compartment to the blood-brain barrier. Proc Natl Acad Sci U S A 2018; 115:E9429-E9438. [PMID: 30217895 DOI: 10.1073/pnas.1802155115] [Citation(s) in RCA: 142] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The endothelial cells that form the blood-brain barrier (BBB) are coated with glycocalyx, on the luminal side, and with the basement membrane and astrocyte endfeet, on the abluminal side. However, it is unclear how exactly the glycocalyx and extravascular structures contribute to BBB properties. We used two-photon microscopy in anesthetized mice to record passive transport of four different-sized molecules-sodium fluorescein (376 Da), Alexa Fluor (643 Da), 40-kDa dextran, and 150-kDa dextran-from blood to brain, at the level of single cortical capillaries. Both fluorescein and Alexa penetrated nearly the entire glycocalyx volume, but the dextrans penetrated less than 60% of the volume. This suggested that the glycocalyx was a barrier for large but not small molecules. The estimated permeability of the endothelium was the same for fluorescein and Alexa but several-fold lower for the larger dextrans. In the extravascular compartment, co-localized with astrocyte endfeet, diffusion coefficients of the dyes were an order of magnitude lower than in the brain parenchyma. This suggested that the astrocyte endfeet and basement membrane also contributed to BBB properties. In conclusion, the passive transport of small and large hydrophilic molecules through the BBB was determined by three separate barriers: the glycocalyx, the endothelium, and the extravascular compartment. All three barriers must be taken into account in drug delivery studies and when considering BBB dysfunction in disease states.
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14
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Tsukiyama A, Murai Y, Matano F, Shirokane K, Morita A. Optical effects on the surrounding structure during quantitative analysis using indocyanine green videoangiography: A phantom vessel study. JOURNAL OF BIOPHOTONICS 2018; 11:e201700254. [PMID: 29193774 DOI: 10.1002/jbio.201700254] [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: 09/05/2017] [Accepted: 11/26/2017] [Indexed: 06/07/2023]
Abstract
Various reports have been published regarding quantitative evaluations of intraoperative fluorescent intensity studies using indocyanine green (ICG) with videoangiography (VAG). The effects of scattering and point-spread functions (PSF) on quantitative ICG-VAG evaluations have not been investigated. Clinically, when ICG is administered through the peripheral vein, it reaches the tissue intra-arterially. To achieve more reliable intraoperative quantitative intensity evaluations, we examined the impact of high-intensity structures on close areas. The study was conducted using a phantom model and surgical fluorescent microscope. A region of interest (ROI) was created for the vessel model and another ROI was created within 3 cm of that. With an ROI of 6.8 mm in the vessel phantom model, 10% intensity was confirmed, even though there was no fluorescent structure. Intensity decreased gradually as the ROI moved further from the vessel model. Our study results suggest that the presence of a high-intensity structure and the size of the ROI may affect quantitative intensity evaluations using ICG-VAG. Results of linear regression analysis indicate that the relationship of intensity (Y) and distance (X) is as follows: Y(real/A) = 29 Exp(-0.062X) + 164.3 Exp(-1.81X). The optical effect should be considered when performing an intraoperative intensity study with a surgical microscope.
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Affiliation(s)
- Atsushi Tsukiyama
- Department of Neurological Surgery, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo, 113-86, Japan
| | - Yasuo Murai
- Department of Neurological Surgery, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo, 113-86, Japan
| | - Fumihiro Matano
- Department of Neurological Surgery, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo, 113-86, Japan
| | - Kazutaka Shirokane
- Department of Neurological Surgery, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo, 113-86, Japan
| | - Akio Morita
- Department of Neurological Surgery, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo, 113-86, Japan
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15
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Abstract
Three-dimensional structures in biological systems are routinely evaluated using large image stacks acquired from fluorescence microscopy; however, analysis of such data is muddled by variability in the signal across and between samples. Here, we present Intensify3D: a user-guided normalization algorithm tailored for overcoming common heterogeneities in large image stacks. We demonstrate the use of Intensify3D for analyzing cholinergic interneurons of adult murine brains in 2-Photon and Light-Sheet fluorescence microscopy, as well as of mammary gland and heart tissues. Beyond enhancement in 3D visualization in all samples tested, in 2-Photon in vivo images, this tool corrected errors in feature extraction of cortical interneurons; and in Light-Sheet microscopy, it enabled identification of individual cortical barrel fields and quantification of somata in cleared adult brains. Furthermore, Intensify3D enhanced the ability to separate signal from noise. Overall, the universal applicability of our method can facilitate detection and quantification of 3D structures and may add value to a wide range of imaging experiments.
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16
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Doi A, Oketani R, Nawa Y, Fujita K. High-resolution imaging in two-photon excitation microscopy using in situ estimations of the point spread function. BIOMEDICAL OPTICS EXPRESS 2018; 9:202-213. [PMID: 29359097 PMCID: PMC5772575 DOI: 10.1364/boe.9.000202] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 12/06/2017] [Accepted: 12/10/2017] [Indexed: 05/06/2023]
Abstract
We present a technique for improving the spatial resolution of two-photon excitation microscopy; our technique combines annular illumination with an in situ estimation of the point spread function (PSF) used for deconvolution. For the in situ estimation of the PSF, we developed a technique called autocorrelation scanning, in which a sample is imaged by the scanning of two excitation foci that are overlapped over various distances. The image series obtained with the variation of the distance between the two foci provides the autocorrelation function of the PSF, which can be used to estimate the PSF at specific positions within a sample. We proved the principle and the effectiveness of this technique through observations of a fluorescent biological sample, and we confirmed that the improvement in the spatial resolution was ~1.7 times that of typical two-photon excitation microscopy by observing a mouse brain phantom at a depth of 200 µm.
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Affiliation(s)
- Atsushi Doi
- Olympus Corporation, 2-3 Kuboyama-cho, Hachioji-shi, Tokyo 192-8512, Japan
| | - Ryosuke Oketani
- Department of Applied Physics, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yasunori Nawa
- Department of Applied Physics, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Katsumasa Fujita
- Department of Applied Physics, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
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17
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Zohrabi M, Cormack RH, Mccullough C, Supekar OD, Gibson EA, Bright VM, Gopinath JT. Numerical analysis of wavefront aberration correction using multielectrode electrowetting-based devices. OPTICS EXPRESS 2017; 25:31451-31461. [PMID: 29245820 PMCID: PMC5941994 DOI: 10.1364/oe.25.031451] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 11/15/2017] [Accepted: 11/16/2017] [Indexed: 05/25/2023]
Abstract
We present numerical simulations of multielectrode electrowetting devices used in a novel optical design to correct wavefront aberration. Our optical system consists of two multielectrode devices, preceded by a single fixed lens. The multielectrode elements function as adaptive optical devices that can be used to correct aberrations inherent in many imaging setups, biological samples, and the atmosphere. We are able to accurately simulate the liquid-liquid interface shape using computational fluid dynamics. Ray tracing analysis of these surfaces shows clear evidence of aberration correction. To demonstrate the strength of our design, we studied three different input aberrations mixtures that include astigmatism, coma, trefoil, and additional higher order aberration terms, with amplitudes as large as one wave at 633 nm.
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Affiliation(s)
- Mo Zohrabi
- Department of Electrical, Computer, and Energy Engineering, University of Colorado, Boulder, CO 80309,
USA
| | - Robert H. Cormack
- Department of Electrical, Computer, and Energy Engineering, University of Colorado, Boulder, CO 80309,
USA
| | - Connor Mccullough
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, CO 80045,
USA
| | - Omkar D. Supekar
- Department of Mechanical Engineering, University of Colorado Boulder, CO 80309,
USA
| | - Emily A. Gibson
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, CO 80045,
USA
| | - Victor M. Bright
- Department of Mechanical Engineering, University of Colorado Boulder, CO 80309,
USA
| | - Juliet T. Gopinath
- Department of Electrical, Computer, and Energy Engineering, University of Colorado, Boulder, CO 80309,
USA
- Department of Physics, University of Colorado, Boulder, CO 80309,
USA
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18
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Dudeck J, Medyukhina A, Fröbel J, Svensson CM, Kotrba J, Gerlach M, Gradtke AC, Schröder B, Speier S, Figge MT, Dudeck A. Mast cells acquire MHCII from dendritic cells during skin inflammation. J Exp Med 2017; 214:3791-3811. [PMID: 29084819 PMCID: PMC5716026 DOI: 10.1084/jem.20160783] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 07/14/2017] [Accepted: 09/13/2017] [Indexed: 12/21/2022] Open
Abstract
Dudeck et al. demonstrate that inflammatory conditions induce dynamic interactions between mast cells (MCs) and dendritic cells (DCs) culminating in protein exchange. Resident MCs are equipped with DC MHCII and empowered to initiate T cell–driven inflammation during migration-based DC absence. Mast cells (MCs) and dendritic cells (DCs) are essential innate sentinels populating host-environment interfaces. Using longitudinal intravital multiphoton microscopy of DCGFP/MCRFP reporter mice, we herein provide in vivo evidence that migratory DCs execute targeted cell-to-cell interactions with stationary MCs before leaving the inflamed skin to draining lymph nodes. During initial stages of skin inflammation, DCs dynamically scan MCs, whereas at a later stage, long-lasting interactions predominate. These innate-to-innate synapse-like contacts ultimately culminate in DC-to-MC molecule transfers including major histocompatibility complex class II (MHCII) proteins enabling subsequent ex vivo priming of allogeneic T cells with a specific cytokine signature. The extent of MHCII transfer to MCs correlates with their T cell priming efficiency. Importantly, preventing the cross talk by preceding DC depletion decreases MC antigen presenting capacity and T cell–driven inflammation. Consequently, we identify an innate intercellular communication arming resident MCs with key DC functions that might contribute to the acute defense potential during critical periods of migration-based DC absence.
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Affiliation(s)
- Jan Dudeck
- Institute for Molecular and Clinical Immunology, Medical Faculty, Otto-von-Guericke University Magdeburg, Magdeburg, Germany.,Institute for Immunology, Medical Faculty Carl-Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Anna Medyukhina
- Applied Systems Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knöll-Institute, Jena, Germany
| | - Julia Fröbel
- Institute for Molecular and Clinical Immunology, Medical Faculty, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Carl-Magnus Svensson
- Applied Systems Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knöll-Institute, Jena, Germany
| | - Johanna Kotrba
- Institute for Molecular and Clinical Immunology, Medical Faculty, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Michael Gerlach
- DFG-Center for Regenerative Therapies Dresden, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany.,Paul Langerhans Institute Dresden of Helmholtz Centre Munich at the University Clinic Carl Gustav Carus of the Technische Universität Dresden, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.,German Centre for Diabetes Research, Dresden, Germany
| | | | - Bernd Schröder
- Institute of Biochemistry, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Stephan Speier
- DFG-Center for Regenerative Therapies Dresden, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany.,Paul Langerhans Institute Dresden of Helmholtz Centre Munich at the University Clinic Carl Gustav Carus of the Technische Universität Dresden, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.,German Centre for Diabetes Research, Dresden, Germany
| | - Marc Thilo Figge
- Applied Systems Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knöll-Institute, Jena, Germany .,Faculty of Biology and Pharmacy, Friedrich Schiller University Jena, Jena, Germany
| | - Anne Dudeck
- Institute for Molecular and Clinical Immunology, Medical Faculty, Otto-von-Guericke University Magdeburg, Magdeburg, Germany .,Institute for Immunology, Medical Faculty Carl-Gustav Carus, Technische Universität Dresden, Dresden, Germany
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19
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Mattison SP, Mondragon E, Kaunas R, Applegate BE. Hybrid nonlinear photoacoustic and reflectance confocal microscopy for label-free subcellular imaging with a single light source. OPTICS LETTERS 2017; 42:4028-4031. [PMID: 28957189 DOI: 10.1364/ol.42.004028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 08/29/2017] [Indexed: 06/07/2023]
Abstract
Nonlinear photoacoustic microscopy is capable of achieving subcellular optically resolved absorption contrast in three dimensions but cannot provide structural context for the acquired images. We have developed a dual-modality imaging system that combines the optical absorption contrast of a nonlinear photoacoustic microscope with the optical scattering contrast of a reflectance confocal microscope. By integrating the confocal detection optics into the optical setup of the nonlinear photoacoustic microscope, the two systems were co-registered and may be acquired at the same time and with the same light source. Simultaneous images of fixed erythrocytes and fibroblasts were measured to demonstrate the complementary information that is provided by the two modalities.
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20
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Lepore M, Portaccio M, Delfino I, Sironi L, La Gatta A, D'Agostino A, Izzo E, Schiraldi C. Physico-optical properties of a crosslinked hyaluronic acid scaffold for biomedical applications. J Appl Polym Sci 2017. [DOI: 10.1002/app.45243] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Maria Lepore
- Dipartimento di Medicina Sperimentale; Università della Campania “Luigi Vanvitelli; Naples I-80123 Italy
| | - Marianna Portaccio
- Dipartimento di Medicina Sperimentale; Università della Campania “Luigi Vanvitelli; Naples I-80123 Italy
| | - Ines Delfino
- Dipartimento di Scienze Ecologiche e Biologiche; Università della Tuscia; Viterbo I-01100 Italy
| | - Laura Sironi
- Dipartimento di Fisica “G. Occhialini”; Università degli Studi di Milano-Bicocca; Milano I-20126 Italy
| | - Annalisa La Gatta
- Dipartimento di Medicina Sperimentale; Università della Campania “Luigi Vanvitelli; Naples I-80123 Italy
| | - Antonella D'Agostino
- Dipartimento di Medicina Sperimentale; Università della Campania “Luigi Vanvitelli; Naples I-80123 Italy
| | - E. Izzo
- Dipartimento di Medicina Sperimentale; Università della Campania “Luigi Vanvitelli; Naples I-80123 Italy
| | - Chiara Schiraldi
- Dipartimento di Medicina Sperimentale; Università della Campania “Luigi Vanvitelli; Naples I-80123 Italy
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21
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Girven KS, Sparta DR. Probing Deep Brain Circuitry: New Advances in in Vivo Calcium Measurement Strategies. ACS Chem Neurosci 2017; 8:243-251. [PMID: 27984692 DOI: 10.1021/acschemneuro.6b00307] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The study of neuronal ensembles in awake and behaving animals is a critical question in contemporary neuroscience research. Through the examination of calcium fluctuations, which are correlated with neuronal activity, we are able to better understand complex neural circuits. Recently, the development of technologies including two-photon microscopy, miniature microscopes, and fiber photometry has allowed us to examine calcium activity in behaving subjects over time. Visualizing changes in intracellular calcium in vivo has been accomplished utilizing GCaMP, a genetically encoded calcium indicator. GCaMP allows researchers to tag cell-type specific neurons with engineered fluorescent proteins that alter their levels of fluorescence in response to changes in intracellular calcium concentration. Even with the evolution of GCaMP, in vivo calcium imaging had yet to overcome the limitation of light scattering, which occurs when imaging from neural tissue in deep brain regions. Currently, researchers have created in vivo methods to bypass this problem; this Review will delve into three of these state of the art techniques: (1) two-photon calcium imaging, (2) single photon calcium imaging, and (3) fiber photometry. Here we discuss the advantages and disadvantages of the three techniques. Continued advances in these imaging techniques will provide researchers with unparalleled access to the inner workings of the brain.
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Affiliation(s)
- Kasey S. Girven
- Department
of Anatomy and Neurobiology and ‡Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States
| | - Dennis R. Sparta
- Department
of Anatomy and Neurobiology and ‡Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland 21201, United States
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22
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Athanasiadis A, Fitzgerald C, Davidson NM, Giorio C, Botchway SW, Ward AD, Kalberer M, Pope FD, Kuimova MK. Dynamic viscosity mapping of the oxidation of squalene aerosol particles. Phys Chem Chem Phys 2016; 18:30385-30393. [DOI: 10.1039/c6cp05674a] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The microscopic viscosity of squalene-based organic aerosol undergoing atmospherically relevant oxidation is investigated.
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Affiliation(s)
| | | | - Nicholas M. Davidson
- School of Geography
- Earth and Environmental Science
- University of Birmingham
- Edgbaston
- UK
| | - Chiara Giorio
- Department of Chemistry
- University of Cambridge
- Cambridge
- UK
| | - Stanley W. Botchway
- Central Laser Facility
- Research Complex at Harwell
- Rutherford Appleton Laboratory
- Oxon OX11 0QX
- UK
| | - Andrew D. Ward
- Central Laser Facility
- Research Complex at Harwell
- Rutherford Appleton Laboratory
- Oxon OX11 0QX
- UK
| | | | - Francis D. Pope
- School of Geography
- Earth and Environmental Science
- University of Birmingham
- Edgbaston
- UK
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23
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Cha JW, Yew EYS, Kim D, Subramanian J, Nedivi E, So PTC. Non-descanned multifocal multiphoton microscopy with a multianode photomultiplier tube. AIP ADVANCES 2015; 5:084802. [PMID: 25874160 PMCID: PMC4387602 DOI: 10.1063/1.4916040] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 09/28/2014] [Indexed: 05/25/2023]
Abstract
Multifocal multiphoton microscopy (MMM) improves imaging speed over a point scanning approach by parallelizing the excitation process. Early versions of MMM relied on imaging detectors to record emission signals from multiple foci simultaneously. For many turbid biological specimens, the scattering of emission photons results in blurred images and degrades the signal-to-noise ratio (SNR). We have recently demonstrated that a multianode photomultiplier tube (MAPMT) placed in a descanned configuration can effectively collect scattered emission photons from each focus into their corresponding anodes significantly improving image SNR for highly scattering specimens. Unfortunately, a descanned MMM has a longer detection path resulting in substantial emission photon loss. Optical design constraints in a descanned geometry further results in significant optical aberrations especially for large field-of-view (FOV), high NA objectives. Here, we introduce a non-descanned MMM based on MAPMT that substantially overcomes most of these drawbacks. We show that we improve signal efficiency up to fourfold with limited image SNR degradation due to scattered emission photons. The excitation foci can also be spaced wider to cover the full FOV of the objective with minimal aberrations. The performance of this system is demonstrated by imaging interneuron morphological structures deep in the brains of living mice.
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Affiliation(s)
- Jae Won Cha
- Department of Mechanical Engineering, Massachusetts Institute of Technology , Cambridge, MA, USA
| | - Elijah Y S Yew
- Department of Mechanical Engineering, Massachusetts Institute of Technology , Cambridge, MA, USA
| | - Daekeun Kim
- Department of Mechanical Engineering, Dankook University , Korea
| | - Jaichandar Subramanian
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology , Cambridge, MA, USA
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24
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Dao L, Glancy B, Lucotte B, Chang LC, Balaban RS, Hsu LY. A Model-based approach for microvasculature structure distortion correction in two-photon fluorescence microscopy images. J Microsc 2015. [PMID: 26224257 DOI: 10.1111/jmi.12281] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This paper investigates a postprocessing approach to correct spatial distortion in two-photon fluorescence microscopy images for vascular network reconstruction. It is aimed at in vivo imaging of large field-of-view, deep-tissue studies of vascular structures. Based on simple geometric modelling of the object-of-interest, a distortion function is directly estimated from the image volume by deconvolution analysis. Such distortion function is then applied to subvolumes of the image stack to adaptively adjust for spatially varying distortion and reduce the image blurring through blind deconvolution. The proposed technique was first evaluated in phantom imaging of fluorescent microspheres that are comparable in size to the underlying capillary vascular structures. The effectiveness of restoring three-dimensional (3D) spherical geometry of the microspheres using the estimated distortion function was compared with empirically measured point-spread function. Next, the proposed approach was applied to in vivo vascular imaging of mouse skeletal muscle to reduce the image distortion of the capillary structures. We show that the proposed method effectively improve the image quality and reduce spatially varying distortion that occurs in large field-of-view deep-tissue vascular dataset. The proposed method will help in qualitative interpretation and quantitative analysis of vascular structures from fluorescence microscopy images.
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Affiliation(s)
- Lam Dao
- Laboratory of Cardiac Energetics, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, U.S.A.,Department of Electrical Engineering and Computer Science, The Catholic University of America, Washington, District of Columbia, U.S.A
| | - Brian Glancy
- Laboratory of Cardiac Energetics, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, U.S.A
| | - Bertrand Lucotte
- Laboratory of Cardiac Energetics, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, U.S.A
| | - Lin-Ching Chang
- Department of Electrical Engineering and Computer Science, The Catholic University of America, Washington, District of Columbia, U.S.A
| | - Robert S Balaban
- Laboratory of Cardiac Energetics, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, U.S.A
| | - Li-Yueh Hsu
- Laboratory of Cardiac Energetics, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, U.S.A
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25
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26
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So PTC, Yew EYS, Rowlands C. High-throughput nonlinear optical microscopy. Biophys J 2014; 105:2641-54. [PMID: 24359736 DOI: 10.1016/j.bpj.2013.08.051] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 08/19/2013] [Accepted: 08/22/2013] [Indexed: 01/06/2023] Open
Abstract
High-resolution microscopy methods based on different nonlinear optical (NLO) contrast mechanisms are finding numerous applications in biology and medicine. While the basic implementations of these microscopy methods are relatively mature, an important direction of continuing technological innovation lies in improving the throughput of these systems. Throughput improvement is expected to be important for studying fast kinetic processes, for enabling clinical diagnosis and treatment, and for extending the field of image informatics. This review will provide an overview of the fundamental limitations on NLO microscopy throughput. We will further cover several important classes of high-throughput NLO microscope designs with discussions on their strengths and weaknesses and their key biomedical applications. Finally, this review will close with a perspective of potential future technological improvements in this field.
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Affiliation(s)
- Peter T C So
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts; Laser Biomedical Research Center, Massachusetts Institute of Technology, Cambridge, Massachusetts; BioSyM Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Singapore, Singapore.
| | - Elijah Y S Yew
- BioSyM Interdisciplinary Research Group, Singapore-MIT Alliance for Research and Technology, Singapore, Singapore
| | - Christopher Rowlands
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts; Laser Biomedical Research Center, Massachusetts Institute of Technology, Cambridge, Massachusetts
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27
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Li S, Shen X, Li L, Yuan P, Guan Z, Yao SQ, Xu QH. Conjugated-polymer-based red-emitting nanoparticles for two-photon excitation cell imaging with high contrast. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:7623-7627. [PMID: 24967827 DOI: 10.1021/la501790y] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Two-photon fluorescence microscopy is a widely used noninvasive bioimaging technique because of unique advantages such as a large penetration depth and 3D mapping capability. Ideal two-photon fluorophores require large two-photon absorption cross sections and red emission with high quantum yields. Here we report red-emitting-dye-doped conjugated polymer nanoparticles that display high two-photon excitation brightness. In these nanoparticles, conjugated polymer (PFV) was chosen as a two-photon light-harvesting material, and red-emitting dyes (MgPc and Nile red) were chosen as the energy acceptors and red-emitting materials. Two-photon excitation fluorescence of MgPc and Nile red was enhanced by up to ∼53 and ∼240 times, respectively. We have successfully demonstrated the application of these conjugated polymer-based nanoparticles in two-photon excitation cancer cell imaging with an excellent contrast ratio. This concept could become a general approach to the preparation of two-photon excitation red-emitting materials for deep-tissue live-cell imaging with high contrast.
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Affiliation(s)
- Shuang Li
- Department of Chemistry, National University of Singapore , 3 Science Drive 3, Republic of Singapore 117543
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28
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Rapid stimulus-evoked astrocyte Ca2+ elevations and hemodynamic responses in mouse somatosensory cortex in vivo. Proc Natl Acad Sci U S A 2013; 110:E4678-87. [PMID: 24218625 DOI: 10.1073/pnas.1310065110] [Citation(s) in RCA: 142] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Increased neuron and astrocyte activity triggers increased brain blood flow, but controversy exists over whether stimulation-induced changes in astrocyte activity are rapid and widespread enough to contribute to brain blood flow control. Here, we provide evidence for stimulus-evoked Ca(2+) elevations with rapid onset and short duration in a large proportion of cortical astrocytes in the adult mouse somatosensory cortex. Our improved detection of the fast Ca(2+) signals is due to a signal-enhancing analysis of the Ca(2+) activity. The rapid stimulation-evoked Ca(2+) increases identified in astrocyte somas, processes, and end-feet preceded local vasodilatation. Fast Ca(2+) responses in both neurons and astrocytes correlated with synaptic activity, but only the astrocytic responses correlated with the hemodynamic shifts. These data establish that a large proportion of cortical astrocytes have brief Ca(2+) responses with a rapid onset in vivo, fast enough to initiate hemodynamic responses or influence synaptic activity.
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29
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Two-photon imaging of nonlinear glutamate release dynamics at bipolar cell synapses in the mouse retina. J Neurosci 2013; 33:10972-85. [PMID: 23825403 DOI: 10.1523/jneurosci.1241-13.2013] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Alpha/Y-type retinal ganglion cells encode visual information with a receptive field composed of nonlinear subunits. This nonlinear subunit structure enhances sensitivity to patterns composed of high spatial frequencies. The Y-cell's subunits are the presynaptic bipolar cells, but the mechanism for the nonlinearity remains incompletely understood. We investigated the synaptic basis of the subunit nonlinearity by combining whole-cell recording of mouse Y-type ganglion cells with two-photon fluorescence imaging of a glutamate sensor (iGluSnFR) expressed on their dendrites and throughout the inner plexiform layer. A control experiment designed to assess iGluSnFR's dynamic range showed that fluorescence responses from Y-cell dendrites increased proportionally with simultaneously recorded excitatory current. Spatial resolution was sufficient to readily resolve independent release at intermingled ON and OFF bipolar terminals. iGluSnFR responses at Y-cell dendrites showed strong surround inhibition, reflecting receptive field properties of presynaptic release sites. Responses to spatial patterns located the origin of the Y-cell nonlinearity to the bipolar cell output, after the stage of spatial integration. The underlying mechanism differed between OFF and ON pathways: OFF synapses showed transient release and strong rectification, whereas ON synapses showed relatively sustained release and weak rectification. At ON synapses, the combination of fast release onset with slower release offset explained the nonlinear response of the postsynaptic ganglion cell. Imaging throughout the inner plexiform layer, we found transient, rectified release at the central-most levels, with increasingly sustained release near the borders. By visualizing glutamate release in real time, iGluSnFR provides a powerful tool for characterizing glutamate synapses in intact neural circuits.
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30
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Imaging Condition Optimization in Multiphoton Microscopy of Three-Dimensional Collagen Fiber Structures. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.200400165] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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31
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Choi H, Yew EYS, Hallacoglu B, Fantini S, Sheppard CJR, So PTC. Improvement of axial resolution and contrast in temporally focused widefield two-photon microscopy with structured light illumination. BIOMEDICAL OPTICS EXPRESS 2013; 4:995-1005. [PMID: 23847726 PMCID: PMC3704103 DOI: 10.1364/boe.4.000995] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 05/17/2013] [Accepted: 05/29/2013] [Indexed: 05/18/2023]
Abstract
Although temporally focused wide-field two-photon microscopy (TFM) can perform depth resolved wide field imaging, it cannot avoid the image degradation due to scattering of excitation and emission photons when imaging in a turbid medium. Further, its axial resolution is inferior to standard point-scanning two-photon microscopy. We implemented a structured light illumination for TFM and have shown that it can effectively reject the out-of-focus scattered emission photons improving image contrast. Further, the depth resolution of the improved system is dictated by the spatial frequency of the structure light with the potential of attaining depth resolution better than point-scanning two-photon microscopy.
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Affiliation(s)
- Heejin Choi
- Department of Mechanical Engineering Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Elijah Y. S. Yew
- Singapore MIT Alliance for Research and Technology, Singapore 138602, Singapore
| | - Bertan Hallacoglu
- Department of Biomedical Engineering, Tufts University, Medford, Massachusetts 02155, USA
| | - Sergio Fantini
- Department of Biomedical Engineering, Tufts University, Medford, Massachusetts 02155, USA
| | - Colin J. R. Sheppard
- Department of Nanophysics, Istituto Italiano di Tecnologia, Via Morego, 30, 1613 Genova, Italy
| | - Peter T. C. So
- Department of Mechanical Engineering Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Singapore MIT Alliance for Research and Technology, Singapore 138602, Singapore
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32
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33
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Labouta HI, Hampel M, Thude S, Reutlinger K, Kostka KH, Schneider M. Depth profiling of gold nanoparticles and characterization of point spread functions in reconstructed and human skin using multiphoton microscopy. JOURNAL OF BIOPHOTONICS 2012; 5:85-96. [PMID: 22147676 DOI: 10.1002/jbio.201100069] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Multiphoton microscopy has become popular in studying dermal nanoparticle penetration. This necessitates studying the imaging parameters of multiphoton microscopy in skin as an imaging medium, in terms of achievable detection depths and the resolution limit. This would simulate real-case scenarios rather than depending on theoretical values determined under ideal conditions. This study has focused on depth profiling of sub-resolution gold nanoparticles (AuNP) in reconstructed (fixed and unfixed) and human skin using multiphoton microscopy. Point spread functions (PSF) were determined for the used water-immersion objective of 63×/NA = 1.2. Factors such as skin-tissue compactness and the presence of wrinkles were found to deteriorate the accuracy of depth profiling. A broad range of AuNP detectable depths (20-100 μm) in reconstructed skin was observed. AuNP could only be detected up to ∼14 μm depth in human skin. Lateral (0.5 ± 0.1 μm) and axial (1.0 ± 0.3 μm) PSF in reconstructed and human specimens were determined. Skin cells and intercellular components didn't degrade the PSF with depth. In summary, the imaging parameters of multiphoton microscopy in skin and practical limitations encountered in tracking nanoparticle penetration using this approach were investigated.
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Affiliation(s)
- Hagar I Labouta
- Department of Pharmaceutical Nanotechnology, Saarland University, Campus A4 1, 66123 Saarbrücken, Germany
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34
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Young P, Clendenon S, Byars J, Decca R, Dunn K. The effects of spherical aberration on multiphoton fluorescence excitation microscopy. J Microsc 2011; 242:157-65. [PMID: 21118240 PMCID: PMC4449278 DOI: 10.1111/j.1365-2818.2010.03449.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Multiphoton fluorescence excitation microscopy is almost invariably conducted with samples whose refractive index differ from that of the objective immersion medium, conditions that cause spherical aberration. Due to the quadratic nature of multiphoton fluorescence excitation, spherical aberration is expected to profoundly affect the depth dependence of fluorescence excitation. In order to determine the effect of refractive index mismatch in multiphoton fluorescence excitation microscopy, we measured signal attenuation, photobleaching rates and resolution degradation with depth in homogeneous samples with minimal light scattering and absorption over a range of refractive indices. These studies demonstrate that signal levels and resolution both rapidly decline with depth into refractive index mismatched samples. Analyses of photobleaching rates indicate that the preponderance of signal attenuation with depth results from decreased rates of fluorescence excitation, even in a system with a descanned emission collection pathway. Similar results were obtained in analyses of fluorescence microspheres embedded in rat kidney tissue, demonstrating that spherical aberration is an important limiting factor in multiphoton fluorescence excitation microscopy of biological samples.
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Affiliation(s)
- P.A. Young
- Department of Medicine, Division of Nephrology, Indiana University School of Medicine, Indianapolis, Indiana, U.S.A
| | - S.G. Clendenon
- Department of Physics, Indiana University, Bloomington, Indiana, U.S.A
| | - J.M. Byars
- Department of Medicine, Division of Nephrology, Indiana University School of Medicine, Indianapolis, Indiana, U.S.A
| | - R.S. Decca
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, U.S.A
| | - K.W. Dunn
- Department of Medicine, Division of Nephrology, Indiana University School of Medicine, Indianapolis, Indiana, U.S.A
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35
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Young PA, Clendenon SG, Byars JM, Dunn KW. The effects of refractive index heterogeneity within kidney tissue on multiphoton fluorescence excitation microscopy. J Microsc 2011; 242:148-56. [PMID: 21118239 PMCID: PMC4450360 DOI: 10.1111/j.1365-2818.2010.03448.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Although multiphoton fluorescence excitation microscopy has improved the depth at which useful fluorescence images can be collected in biological tissues, the reach of multiphoton fluorescence excitation microscopy is nonetheless limited by tissue scattering and spherical aberration. Scattering can be reduced in fixed samples by mounting in a medium whose refractive index closely matches that of the fixed material. Using optical 'clearing', the effects of refractive index heterogeneity on signal attenuation with depth are investigated. Quantitative measurements show that by mounting kidney tissue in a high refractive index medium, less than 50% of signal attenuates in 100 μm of depth.
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Affiliation(s)
- P A Young
- Department of Medicine, Division of Nephrology, Indiana University School of Medicine, Indianapolis, Indiana 46202–5188, USA
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36
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Dana H, Shoham S. Numerical evaluation of temporal focusing characteristics in transparent and scattering media. OPTICS EXPRESS 2011; 19:4937-4948. [PMID: 21445129 DOI: 10.1364/oe.19.004937] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Temporal focusing is a simple approach for achieving tight, optically sectioned excitation in nonlinear microscopy and multiphoton photo-manipulation. Key applications and advantages of temporal focusing involve propagation through scattering media, but the progressive broadening of the temporal focus has not been characterized. By combining a detailed geometrical optics model with Monte-Carlo scattering simulations we introduce and validate a simulation strategy for predicting temporal focusing characteristics in scattering and non-scattering media. The broadening of the temporal focus width with increasing depth in brain tissue is studied using both simulations and experiments for several key optical geometries, and an analytical approximation is found for the dependence of this broadening on the microscope's parameters in a transparent medium. Our results indicate that a multiphoton temporal focus has radically different broadening characteristics in deep tissue than those of a spatial focus.
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Affiliation(s)
- Hod Dana
- Faculty of Biomedical Engineering, The Technion–I.I.T., Haifa, Israel
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37
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Durr NJ, Weisspfennig CT, Holfeld BA, Ben-Yakar A. Maximum imaging depth of two-photon autofluorescence microscopy in epithelial tissues. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:026008. [PMID: 21361692 PMCID: PMC3061332 DOI: 10.1117/1.3548646] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Endogenous fluorescence provides morphological, spectral, and lifetime contrast that can indicate disease states in tissues. Previous studies have demonstrated that two-photon autofluorescence microscopy (2PAM) can be used for noninvasive, three-dimensional imaging of epithelial tissues down to approximately 150 μm beneath the skin surface. We report ex-vivo 2PAM images of epithelial tissue from a human tongue biopsy down to 370 μm below the surface. At greater than 320 μm deep, the fluorescence generated outside the focal volume degrades the image contrast to below one. We demonstrate that these imaging depths can be reached with 160 mW of laser power (2-nJ per pulse) from a conventional 80-MHz repetition rate ultrafast laser oscillator. To better understand the maximum imaging depths that we can achieve in epithelial tissues, we studied image contrast as a function of depth in tissue phantoms with a range of relevant optical properties. The phantom data agree well with the estimated contrast decays from time-resolved Monte Carlo simulations and show maximum imaging depths similar to that found in human biopsy results. This work demonstrates that the low staining inhomogeneity (∼ 20) and large scattering coefficient (∼ 10 mm(-1)) associated with conventional 2PAM limit the maximum imaging depth to 3 to 5 mean free scattering lengths deep in epithelial tissue.
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Affiliation(s)
- Nicholas J Durr
- University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas 78712, USA
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38
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Zalvidea D, Claverol-Tinturé E. Second Harmonic Generation for time-resolved monitoring of membrane pore dynamics subserving electroporation of neurons. BIOMEDICAL OPTICS EXPRESS 2011; 2:305-314. [PMID: 21339876 PMCID: PMC3038446 DOI: 10.1364/boe.2.000305] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Revised: 12/17/2010] [Accepted: 12/29/2010] [Indexed: 05/30/2023]
Abstract
Electroporation of neurons, i.e. electric-field induced generation of membrane nanopores to facilitate internalization of molecules, is a classic technique used in basic neuroscience research and recently has been proposed as a promising therapeutic strategy in the area of neuro-oncology. To optimize electroporation parameters, optical techniques capable of delivering time and spatially-resolved information on electroporation pore formation at the nanometer scale would be advantageous. For this purpose we describe here a novel optical method based on second harmonic generation (SHG) microscopy. Due to the nonlinear and coherent nature of SHG, the 3D radiation lobes from stained neuronal membranes are sensitive to the spatial distribution of scatterers in the illuminated patch, and in particular to nanopore formation.We used phase-array analysis to computationally study the SHG signal as a function of nanopore size and nanopore population density and confirmed experimentally, in accordance with previous work, the dependence of nanopore properties on membrane location with respect to the electroporation electric field; higher nanopore densities, lasting < 5 milliseconds, are observed at membrane patches perpendicular to the field whereas lower density is observed at partly tangent locations. Differences between near-anode and near-cathode cell poles are also measured, showing higher pore densities at the anodic pole compared to cathodic pole. This technique is promising for the study of nanopore dynamics in neurons and for the optimization of novel electroporation-based therapeutic approaches.
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Affiliation(s)
- Dobryna Zalvidea
- Neuroengineering Group, IBEC-Institut de Bioenginyeria de Catalunya, Baldiri Reixac 15-21, Barcelona 08028, Spain
| | - Enric Claverol-Tinturé
- Neuroengineering Group, IBEC-Institut de Bioenginyeria de Catalunya, Baldiri Reixac 15-21, Barcelona 08028, Spain
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39
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Hayakawa CK, Potma EO, Venugopalan V. Electric field Monte Carlo simulations of focal field distributions produced by tightly focused laser beams in tissues. BIOMEDICAL OPTICS EXPRESS 2011; 2:278-90. [PMID: 21339874 PMCID: PMC3039457 DOI: 10.1364/boe.2.000278] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Revised: 12/13/2010] [Accepted: 12/14/2010] [Indexed: 05/15/2023]
Abstract
The focal field distribution of tightly focused laser beams in turbid media is sensitive to optical scattering and therefore of direct relevance to image quality in confocal and nonlinear microscopy. A model that considers both the influence of scattering and diffraction on the amplitude and phase of the electric field in focused beam geometries is required to describe these distorted focal fields. We combine an electric field Monte Carlo approach that simulates the electric field propagation in turbid media with an angular-spectrum representation of diffraction theory to analyze the effect of tissue scattering properties on the focal field. In particular, we examine the impact of variations in the scattering coefficient (µ(s)), single-scattering anisotropy (g), of the turbid medium and the numerical aperture of the focusing lens on the focal volume at various depths. The model predicts a scattering-induced broadening, amplitude loss, and depolarization of the focal field that corroborates experimental results. We find that both the width and the amplitude of the focal field are dictated primarily by µ(s) with little influence from g. In addition, our model confirms that the depolarization rate is small compared to the amplitude loss of the tightly focused field.
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Affiliation(s)
- Carole K. Hayakawa
- Department of Chemical Engineering and Materials Science, Beckman Laser Institute, University of California, Irvine Irvine, California 92697, USA
- Laser Microbeam and Medical Program, Beckman Laser Institute, University of California, Irvine Irvine, California 92697, USA
| | - Eric O. Potma
- Department of Chemistry, Beckman Laser Institute, University of California, Irvine Irvine, California 92697, USA
- Laser Microbeam and Medical Program, Beckman Laser Institute, University of California, Irvine Irvine, California 92697, USA
| | - Vasan Venugopalan
- Department of Chemical Engineering and Materials Science, Beckman Laser Institute, University of California, Irvine Irvine, California 92697, USA
- Laser Microbeam and Medical Program, Beckman Laser Institute, University of California, Irvine Irvine, California 92697, USA
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40
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König K, Speicher M, Köhler MJ, Scharenberg R, Kaatz M. Clinical application of multiphoton tomography in combination with high-frequency ultrasound for evaluation of skin diseases. JOURNAL OF BIOPHOTONICS 2010; 3:759-773. [PMID: 20680976 DOI: 10.1002/jbio.201000074] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The first-ever application of high-frequency ultrasound combined with multiphoton tomography (MPT) and dermoscopy in a clinical trial is reported. 47 patients with different dermatoses such as benign and malign skin cancers, connective tissue diseases, inflammatory skin diseases, and autoimmune bullous skin diseases have been investigated with (i) state-of-the-art and highly sophisticated ultrasound systems for dermatology, (ii) the femtosecond laser multiphoton tomograph and (iii) dermoscopes. Dermoscopy provides two-dimensional color images of the skin surface with a magnification up to 70 x. Depending on the ultrasonic frequencies from 7.5 MHz to 100 MHz, the signal depth varies from about 1 mm to 80 mm. Vertical ultrasound wide-field images provide fast information on depth and volume of the lesion. The 100 MHz ultrasound allows imaging with resolutions down to 16 μm (axial) and 32 μm (lateral). Multiphoton tomography provides 0.36 x 0.36 x 0.001 mm³ horizontal optical sections of a particular region of interest with submicron resolution down to 200 μm tissue depth. The autofluorescence of mitochondrial coenzymes, keratin, melanin, and elastin as well as the network of collagen structures can be imaged. The combination of ultrasound and MPT opens novel synergistic possibilities in diagnostics of skin diseases with a special focus on the early detection of skin cancer as well as the evaluation of treatments.
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Affiliation(s)
- Karsten König
- JenLab GmbH, Schillerstraße 1, 07745 Jena and Campus A1.2, 66123 Saarbrücken, Germany
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41
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Guldbrand S, Simonsson C, Goksör M, Smedh M, Ericson MB. Two-photon fluorescence correlation microscopy combined with measurements of point spread function; investigations made in human skin. OPTICS EXPRESS 2010; 18:15289-15302. [PMID: 20720906 DOI: 10.1364/oe.18.015289] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Two-photon excitation fluorescence correlation spectroscopy (TPFCS) has been applied in connection to measurements of the point spread function (PSF) for quantitative analysis of sulphorhodamine B (SRB) in excised human skin. The PSF was measured using subresolution fluorescent beads embedded in the skin specimen. The PSF, measured as full width at half maximum (FWHM) was found to be 0.41 +/- 0.05 microm in the lateral direction, and 1.2 +/- 0.4 microm in the axial direction. The molecular diffusion of SRB inside the skin ranged between 0.5 and 15.0 x 10(-8) cm(2)/s. The diffusion coefficient is not dependent on depths down to 40 microm. The fluorophores were found to accumulate on the upper layers of the skin. This work is the first TPFCS study in human skin. The results show that TPFCS can be used for quantitative analyses of fluorescent compounds in human skin.
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Affiliation(s)
- Stina Guldbrand
- Department of Physics, University of Gothenburg, 412 96 Gothenburg, Sweden.
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42
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Zhu J, Yong KT, Roy I, Hu R, Ding H, Zhao L, Swihart MT, He GS, Cui Y, Prasad PN. Additive controlled synthesis of gold nanorods (GNRs) for two-photon luminescence imaging of cancer cells. NANOTECHNOLOGY 2010; 21:285106. [PMID: 20585168 DOI: 10.1088/0957-4484/21/28/285106] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Gold nanorods (GNRs) with a longitudinal surface plasmon resonance peak that is tunable from 600 to 1100 nm have been fabricated in a cetyl trimethylammoniumbromide (CTAB) micellar medium using hydrochloric acid and silver nitrate as additives to control their shape and size. By manipulating the concentrations of silver nitrate and hydrochloric acid, the aspect ratio of the GNRs was reliably and reproducibly tuned from 2.5 to 8. The GNRs were first coated with polyelectrolyte multilayers and then bioconjugated to transferrin (Tf) to target pancreatic cancer cells. Two-photon imaging excited from the bioconjugated GNRs demonstrated receptor-mediated uptake of the bioconjugates into Panc-1 cells, overexpressing the transferrin receptor (TfR). The bioconjugated GNR formulation exhibited very low toxicity, suggesting that it is biocompatible and potentially suitable for targeted two-photon bioimaging.
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Affiliation(s)
- Jing Zhu
- Institute for Lasers, Photonics and Biophotonics, University at Buffalo, The State University of New York, Buffalo, NY 14260-4200, USA
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43
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Agrawal A, Pfefer TJ, Gilani N, Drezek R. Three-dimensional characterization of optical coherence tomography point spread functions with a nanoparticle-embedded phantom. OPTICS LETTERS 2010; 35:2269-71. [PMID: 20596216 DOI: 10.1364/ol.35.002269] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We present a novel (to our knowledge) approach for measurement of the three-dimensional point spread function (PSF) of optical coherence tomography (OCT) systems using a nanoparticle-embedded phantom (NEP), toward development of standardized test methods for biophotonic imaging. The NEP comprises highly reflective plasmonic nanoparticles, homogeneously distributed in a transparent silicone matrix. OCT image volumes were analyzed to characterize PSFs in axial and lateral directions at a variety of locations in the NEP. Results indicate submicrometer agreement with conventional approaches to measure dimensions of the PSF. The NEP offers a robust approach for validating and comparing imaging performance of OCT devices.
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Affiliation(s)
- Anant Agrawal
- Optical Diagnostic Devices Laboratory, Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, Maryland 20993, USA.
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44
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Multiphotonenmikroskopie und In-vivo-Multiphotonentomographie in der dermatologischen Bildgebung. DER HAUTARZT 2010; 61:397-409. [DOI: 10.1007/s00105-009-1880-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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45
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Steven P, Müller M, Koop N, Rose C, Hüttmann G. Comparison of Cornea Module and DermaInspect for noninvasive imaging of ocular surface pathologies. JOURNAL OF BIOMEDICAL OPTICS 2009; 14:064040. [PMID: 20059278 DOI: 10.1117/1.3275475] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Minimally invasive imaging of ocular surface pathologies aims at securing clinical diagnosis without actual tissue probing. For this matter, confocal microscopy (Cornea Module) is in daily use in ophthalmic practice. Multiphoton microscopy is a new optical technique that enables high-resolution imaging and functional analysis of living tissues based on tissue autofluorescence. This study was set up to compare the potential of a multiphoton microscope (DermaInspect) to the Cornea Module. Ocular surface pathologies such as pterygia, papillomae, and nevi were investigated in vivo using the Cornea Module and imaged immediately after excision by DermaInspect. Two excitation wavelengths, fluorescence lifetime imaging and second-harmonic generation (SHG), were used to discriminate different tissue structures. Images were compared with the histopathological assessment of the samples. At wavelengths of 730 nm, multiphoton microscopy exclusively revealed cellular structures. Collagen fibrils were specifically demonstrated by second-harmonic generation. Measurements of fluorescent lifetimes enabled the highly specific detection of goblet cells, erythrocytes, and nevus-cell clusters. At the settings used, DermaInspect reaches higher resolutions than the Cornea Module and obtains additional structural information. The parallel detection of multiphoton excited autofluorescence and confocal imaging could expand the possibilities of minimally invasive investigation of the ocular surface toward functional analysis at higher resolutions.
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Affiliation(s)
- Philipp Steven
- University Medical Center of Schleswig-Holstein, Department of Ophthalmology and University of Luebeck, Institute of Anatomy, Ratzeburger Allee 160, Luebeck 23538 Germany.
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46
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Starosta MS, Dunn AK. Three-dimensional computation of focused beam propagation through multiple biological cells. OPTICS EXPRESS 2009; 17:12455-69. [PMID: 19654647 DOI: 10.1364/oe.17.012455] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The FDTD method was used to simulate focused Gaussian beam propagation through multiple inhomogeneous biological cells. To our knowledge this is the first three dimensional computational investigation of a focused beam interacting with multiple biological cells using FDTD. A parametric study was performed whereby three simulated cells were varied by organelle density, nuclear type and arrangement of internal cellular structure and the beam focus depth was varied within the cluster of cells. Of the organelle types investigated, it appears that the cell nuclei are responsible for the greatest scattering of the focused beam in the configurations studied. Additional simulations to determine the optical scattering from 27 cells were also run and compared to the three cell case. No significant degradation of two-photon lateral imaging resolution was predicted to occur within the first 40 microm of imaging depth.
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Affiliation(s)
- Matthew S Starosta
- Department of Biomedical Engineering, The University of Texas at Austin, Texas 78712, USA.
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47
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Yasui T, Takahashi Y, Ito M, Fukushima S, Araki T. Ex vivo and in vivo second-harmonic-generation imaging of dermal collagen fiber in skin: comparison of imaging characteristics between mode-locked Cr:forsterite and Ti:sapphire lasers. APPLIED OPTICS 2009; 48:D88-95. [PMID: 19340128 DOI: 10.1364/ao.48.000d88] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Second-harmonic-generation (SHG) microscopy is an interesting new tool for observing dermal collagen fiber in skin. However, conventional SHG microscopy using a mode-locked Ti:sapphire laser suffers from low penetration depth and a slow image acquisition rate caused by scattering and absorption in tissue, making it difficult to use for in vivo applications on human skin. We develop an SHG microscope equipped with a mode-locked Cr:forsterite laser with a long wavelength and compare its imaging characteristics with that of a Ti:sapphire-laser-based SHG microscope for the measurement of dermal collagen fiber in animal and human skins. The results indicate the suitability of the Cr:forsterite laser-based SHG microscope for in vivo imaging of human skin.
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Affiliation(s)
- Takeshi Yasui
- Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531, Japan.
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48
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Bigelow AW, Geard CR, Randers-Pehrson G, Brenner DJ. Microbeam-integrated multiphoton imaging system. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:123707. [PMID: 19123569 PMCID: PMC2736647 DOI: 10.1063/1.3043439] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2008] [Accepted: 11/18/2008] [Indexed: 05/25/2023]
Abstract
Multiphoton microscopy has been added to the array of imaging techniques at the endstation for the Microbeam II cell irradiator at Columbia University's Radiological Research Accelerator Facility (RARAF). This three-dimensional (3D), laser-scanning microscope functions through multiphoton excitation, providing an enhanced imaging routine during radiation experiments with tissuelike samples, such as small living animals and organisms. Studies at RARAF focus on radiation effects; hence, this multiphoton microscope was designed to observe postirradiation cellular dynamics. This multiphoton microscope was custom designed into an existing Nikon Eclipse E600-FN research fluorescence microscope on the irradiation platform. Design details and biology applications using this enhanced 3D-imaging technique at RARAF are reviewed.
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Affiliation(s)
- Alan W Bigelow
- Center for Radiological Research, Columbia University, New York, New York 10032, USA
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49
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König K, Weinigel M, Hoppert D, Bückle R, Schubert H, Köhler MJ, Kaatz M, Elsner P. Multiphoton tissue imaging using high-NA microendoscopes and flexible scan heads for clinical studies and small animal research. JOURNAL OF BIOPHOTONICS 2008; 1:506-13. [PMID: 19343676 DOI: 10.1002/jbio.200810049] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Multiphoton tomographs based on femtosecond laser and GRIN lens technology in combination with flexible scan heads have been developed for clinical high-resolution tissue imaging and small animal research. The novel tissue tomograph possesses a 0.5 m long flexible mirror arm in combination with piezodriven focusing optics and multiple single photon counting PMT detectors. The photodetectors are in particular useful to obtain information on the extracellular matrix by the simultaneous measurement of the two-photon autofluorescence of elastin as well as the second harmonic generation of collagen. A major application is the in vivo determination of the skin age index. The rigid two-photon microendoscope with a high numerical aperture of 0.8 is based on a combination of silver-doped 1.0 mm rod-shaped GRIN lens with a hemispheric front optics. It was used in combination with the multiphoton tomograph for clinical studies as well as for inner organ and eye imaging of small animals.
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Affiliation(s)
- Karsten König
- Saarland University, Faculty of Mechatronics and Physics, Campus, 66123 Saarbrücken, Germany.
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Megens RTA, oude Egbrink MGA, Merkx M, Slaaf DW, van Zandvoort MAMJ. Two-photon microscopy on vital carotid arteries: imaging the relationship between collagen and inflammatory cells in atherosclerotic plaques. JOURNAL OF BIOMEDICAL OPTICS 2008; 13:044022. [PMID: 19021350 DOI: 10.1117/1.2965542] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We used two-photon laser scanning microscopy (TPLSM) to demonstrate for the first time its potential in studying relational details at the cellular level of atherogenesis in intact, viable mouse carotid arteries. Isolated and mounted arteries of ApoE-/-mice, aged 15 or 21 weeks (7 and 13 weeks on western diet), were imaged after labeling with specific fluorescent markers for cell nuclei, inflammatory cells, collagen, and lipids. Data were compared with C57BL6/J mice fed a chow diet. Control vessels had intact endothelium without adhering blood cells or significant intimal collagen labeling. In ApoE-/-mice already at 15 weeks, inflammatory cells adhered to the endothelium and increased labeling of collagen was observed in tunica intima at both lesion-prone and non-lesion-prone sites, indicating endothelium activation. In plaques, internalized inflammatory cell density increased with age and plaque progression in tunicae adventitia and intima, but not media. In the whole plaque, aging or plaque progression did not alter the direct relationship between inflammatory cells and collagen. However, within the fibrous caps specifically, direct contact between inflammatory cells and collagen increased with age. This study demonstrates the potential of TPLSM in determining detailed information regarding the complex relationship between inflammatory cells and collagen during atherogenesis.
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Affiliation(s)
- Remco T A Megens
- Maastricht University, Cardiovascular Research Institute Maastricht, Department of Biomedical Engineering, Universiteitssingel 50, 6229 ER, Maastricht, The Netherlands
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