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Development of novel porphyrin/combretastatin A-4 conjugates for bimodal chemo and photodynamic therapy: Synthesis, photophysical and TDDFT computational studies. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2022.114138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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2
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Sun X, Liu Z, Wang Z, Huo M, Zhang HY, Liu Y. Inclusion-Activated Reversible E/ Z Isomerization of a Cyanostilbene Derivative Based on Cucurbit[8]uril under 365 nm Ultraviolet Irradiation. J Org Chem 2022; 87:7658-7664. [PMID: 35658514 DOI: 10.1021/acs.joc.2c00185] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The photoisomerization behavior of cyanostilbene molecules is a hotspot in supramolecular configuration transformation research. Here, we reported a cyanostilbene derivative that converted from the Z,Z-isomer to the E,E-isomer under UV light irradiation at 365 nm. This process can be reversibly converted only in the presence of cucurbit[8]uril under the same light source, accompanied by the reversible conversion of fluorescence from green to yellow. No effective configuration transformation occurred with guest molecules only or upon the addition of cucurbit[7]uril. The photoisomerization was fully characterized by UV-vis and fluorescence spectroscopy, NMR, high-resolution mass spectrometry, and transmission electron microscopy. This work provides a new method for the supramolecular macrocyclic-activated configuration transformation.
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Affiliation(s)
- Xiaohan Sun
- College of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Zhixue Liu
- College of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Ze Wang
- College of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Man Huo
- College of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Heng-Yi Zhang
- College of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. China
| | - Yu Liu
- College of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. China
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3
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Fazel M, Jazani S, Scipioni L, Vallmitjana A, Gratton E, Digman MA, Pressé S. High Resolution Fluorescence Lifetime Maps from Minimal Photon Counts. ACS PHOTONICS 2022; 9:1015-1025. [PMID: 35847830 PMCID: PMC9278809 DOI: 10.1021/acsphotonics.1c01936] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Fluorescence lifetime imaging microscopy (FLIM) may reveal subcellular spatial lifetime maps of key molecular species. Yet, such a quantitative picture of life necessarily demands high photon budgets at every pixel under the current analysis paradigm, thereby increasing acquisition time and photodamage to the sample. Motivated by recent developments in computational statistics, we provide a direct means to update our knowledge of the lifetime maps of species of different lifetimes from direct photon arrivals, while accounting for experimental features such as arbitrary forms of the instrument response function (IRF) and exploiting information from empty laser pulses not resulting in photon detection. Our ability to construct lifetime maps holds for arbitrary lifetimes, from short lifetimes (comparable to the IRF) to lifetimes exceeding interpulse times. As our method is highly data efficient, for the same amount of data normally used to determine lifetimes and photon ratios, working within the Bayesian paradigm, we report direct blind unmixing of lifetimes with subnanosecond resolution and subpixel spatial resolution using standard raster scan FLIM images. We demonstrate our method using a wide range of simulated and experimental data.
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Affiliation(s)
- Mohamadreza Fazel
- Center
for Biological Physics, Department of Physics, Arizona State University, Tempe, Arizona 85287, United States
| | - Sina Jazani
- Center
for Biological Physics, Department of Physics, Arizona State University, Tempe, Arizona 85287, United States
| | - Lorenzo Scipioni
- Department
of Biomedical Engineering, University of
California Irvine, Irvine, California 92697, United States
- Laboratory
of Fluorescence Dynamics, The Henry Samueli School of Engineering, University of California, Irvine, California 92697, United States
| | - Alexander Vallmitjana
- Department
of Biomedical Engineering, University of
California Irvine, Irvine, California 92697, United States
- Laboratory
of Fluorescence Dynamics, The Henry Samueli School of Engineering, University of California, Irvine, California 92697, United States
| | - Enrico Gratton
- Department
of Biomedical Engineering, University of
California Irvine, Irvine, California 92697, United States
- Laboratory
of Fluorescence Dynamics, The Henry Samueli School of Engineering, University of California, Irvine, California 92697, United States
| | - Michelle A. Digman
- Department
of Biomedical Engineering, University of
California Irvine, Irvine, California 92697, United States
- Laboratory
of Fluorescence Dynamics, The Henry Samueli School of Engineering, University of California, Irvine, California 92697, United States
| | - Steve Pressé
- Center
for Biological Physics, Department of Physics, Arizona State University, Tempe, Arizona 85287, United States
- School
of Molecular Science, Arizona State University, Tempe, Arizona 85287, United States
- E-mail:
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4
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Ahmed AR, Candeo A, D'Abrantes S, Needham SR, Yadav RB, Botchway SW, Parker AW. Directly imaging the localisation and photosensitization properties of the pan-mTOR inhibitor, AZD2014, in living cancer cells. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2020; 213:112055. [PMID: 33142217 PMCID: PMC7762844 DOI: 10.1016/j.jphotobiol.2020.112055] [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: 05/27/2020] [Revised: 09/24/2020] [Accepted: 10/12/2020] [Indexed: 12/17/2022]
Abstract
The range of cellular functions the mechanistic target of rapamycin (mTOR) protein performs makes it an attractive drug target for cancer therapy. However, the cellular localisation and mode of action of second generation inhibitors of mTOR is poorly understood despite the level of attention there is in targeting the mTOR protein. We have therefore studied the properties of the pan-mTOR inhibitor AZD2014, an ideal candidate to study because it is naturally fluorescent, characterising its photochemical properties in solution phase (DMSO, PBS and BSA) and within living cells, where it localises within both the nucleus and the cytoplasm but with different excited state lifetimes of 4.8 (+/- 0.5) and 3.9 (+/- 0.4) ns respectively. We measure the uptake of the inhibitor AZD2014 (7 μM) in monolayer HEK293 cells occurring with a half-life of 1 min but observe complex behaviour for 3D spheroids with the core of the spheroid showing a slower uptake and a slow biphasic behaviour at longer times. From a cellular perspective using fluorescence lifetime imaging microscopy AZD2014 was found to interact directly with GFP-tagged mTORC1 proteins including the downstream target, S6K1. We observe light sensitive behaviour of the cells containing AZD2014 which leads to cell death, in both monolayer and spheroids cells, demonstrating the potential of AZD2014 to act as a possible photodynamic drug under both single photon and multiphoton excitation and discuss its use as a photosensitizer. We also briefly characterise another pan-mTOR inhibitor, INK128.
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Affiliation(s)
- Abdullah R Ahmed
- Central Laser Facility, Science & Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire OX11 0QX, UK; Larch House, Woodlands Business Park, Breckland, Linford Wood, Milton Keynes MK14 6FG, UK
| | - Alessia Candeo
- Central Laser Facility, Science & Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire OX11 0QX, UK
| | - Sofia D'Abrantes
- Central Laser Facility, Science & Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire OX11 0QX, UK; CRUK/MRC Oxford Institute for Radiation Oncology, University of Oxford, Gray Laboratories, ORCRB Roosevelt Drive, Oxford OX3 7DQ, UK
| | - Sarah R Needham
- Central Laser Facility, Science & Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire OX11 0QX, UK
| | - Rahul B Yadav
- Evotec (UK) Ltd, 114 Innovation Drive, Milton Park, Abingdon, Oxfordshire OX14 4RZ, UK
| | - Stanley W Botchway
- Central Laser Facility, Science & Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire OX11 0QX, UK.
| | - Anthony W Parker
- Central Laser Facility, Science & Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire OX11 0QX, UK.
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5
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Sailer A, Ermer F, Kraus Y, Bingham R, Lutter FH, Ahlfeld J, Thorn-Seshold O. Potent hemithioindigo-based antimitotics photocontrol the microtubule cytoskeleton in cellulo. Beilstein J Org Chem 2020; 16:125-134. [PMID: 32082431 PMCID: PMC7006478 DOI: 10.3762/bjoc.16.14] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 11/13/2019] [Indexed: 12/23/2022] Open
Abstract
Background: Hemithioindigo is a promising molecular photoswitch that has only recently been applied as a photoswitchable pharmacophore for control over bioactivity in cellulo. Uniquely, in contrast to other photoswitches that have been applied to biology, the pseudosymmetric hemithioindigo scaffold has allowed the creation of both dark-active and lit-active photopharmaceuticals for the same binding site by a priori design. However, the potency of previous hemithioindigo photopharmaceuticals has not been optimal for their translation to other biological models. Results: Inspired by the structure of tubulin-inhibiting indanones, we created hemithioindigo-based indanone-like tubulin inhibitors (HITubs) and optimised their cellular potency as antimitotic photopharmaceuticals. These HITubs feature reliable and robust visible-light photoswitching and high fatigue resistance. The use of the hemithioindigo scaffold also permitted us to employ a para-hydroxyhemistilbene motif, a structural feature which is denied to most azobenzenes due to the negligibly short lifetimes of their metastable Z-isomers, which proved crucial to enhancing the potency and photoswitchability. The HITubs were ten times more potent than previously reported hemithioindigo photopharmaceutical antimitotics in a series of cell-free and cellular assays, and allowed robust photocontrol over tubulin polymerisation, microtubule (MT) network structure, cell cycle, and cell survival. Conclusions: HITubs represent a powerful addition to the growing toolbox of photopharmaceutical reagents for MT cytoskeleton research. Additionally, as the hemithioindigo scaffold allows photoswitchable bioactivity for substituent patterns inaccessible to the majority of current photopharmaceuticals, wider adoption of the hemithioindigo scaffold may significantly expand the scope of cellular and in vivo targets addressable by photopharmacology.
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Affiliation(s)
- Alexander Sailer
- Department of Pharmacy, Ludwig Maximilian University of Munich, Butenandtstraße 5-13, Munich 81377, Germany
| | - Franziska Ermer
- Department of Pharmacy, Ludwig Maximilian University of Munich, Butenandtstraße 5-13, Munich 81377, Germany
| | - Yvonne Kraus
- Department of Pharmacy, Ludwig Maximilian University of Munich, Butenandtstraße 5-13, Munich 81377, Germany
| | - Rebekkah Bingham
- Department of Pharmacy, Ludwig Maximilian University of Munich, Butenandtstraße 5-13, Munich 81377, Germany
| | - Ferdinand H Lutter
- Department of Pharmacy, Ludwig Maximilian University of Munich, Butenandtstraße 5-13, Munich 81377, Germany
| | - Julia Ahlfeld
- Department of Pharmacy, Ludwig Maximilian University of Munich, Butenandtstraße 5-13, Munich 81377, Germany
| | - Oliver Thorn-Seshold
- Department of Pharmacy, Ludwig Maximilian University of Munich, Butenandtstraße 5-13, Munich 81377, Germany
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6
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Sailer A, Ermer F, Kraus Y, Lutter FH, Donau C, Bremerich M, Ahlfeld J, Thorn‐Seshold O. Hemithioindigos for Cellular Photopharmacology: Desymmetrised Molecular Switch Scaffolds Enabling Design Control over the Isomer‐Dependency of Potent Antimitotic Bioactivity. Chembiochem 2019; 20:1305-1314. [DOI: 10.1002/cbic.201800752] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Indexed: 01/28/2023]
Affiliation(s)
- Alexander Sailer
- Department of PharmacyLudwig-Maximilians University Munich Butenandtstrasse 5–13 Munich 81377 Germany
| | - Franziska Ermer
- Department of PharmacyLudwig-Maximilians University Munich Butenandtstrasse 5–13 Munich 81377 Germany
| | - Yvonne Kraus
- Department of PharmacyLudwig-Maximilians University Munich Butenandtstrasse 5–13 Munich 81377 Germany
| | - Ferdinand H. Lutter
- Department of PharmacyLudwig-Maximilians University Munich Butenandtstrasse 5–13 Munich 81377 Germany
| | - Carsten Donau
- Department of PharmacyLudwig-Maximilians University Munich Butenandtstrasse 5–13 Munich 81377 Germany
| | - Maximilian Bremerich
- Department of PharmacyLudwig-Maximilians University Munich Butenandtstrasse 5–13 Munich 81377 Germany
| | - Julia Ahlfeld
- Department of PharmacyLudwig-Maximilians University Munich Butenandtstrasse 5–13 Munich 81377 Germany
| | - Oliver Thorn‐Seshold
- Department of PharmacyLudwig-Maximilians University Munich Butenandtstrasse 5–13 Munich 81377 Germany
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7
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Holzmann N, Bernasconi L, Bisby RH, Parker AW. Influence of charge transfer on the isomerisation of stilbene derivatives for application in cancer therapy. Phys Chem Chem Phys 2018; 20:27778-27790. [PMID: 30378611 DOI: 10.1039/c8cp05375h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The photoisomerisation of non-toxic trans-combretastatin CA4 to its cytotoxic cis isomer demonstrates the high potential of this and similar compounds for localised cancer therapy. The introduction of intramolecular charge-transfer character by altering the substituents of combretastatin systems opens up possibilities to tailor these stilbene derivatives to the special demands of anticancer drugs. In this TDDFT study we explore how absorption wavelengths for both the trans and cis isomers can be red shifted to enable deeper light penetration into tissue and how the trans → cis and cis → trans isomerisations are affected by charge transfer effects to different degrees.
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Affiliation(s)
- Nicole Holzmann
- STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX, UK.
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8
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Mandal P, Malviya N, Kundu BK, Dhankhar SS, Nagaraja C, Mukhopadhyay S. RAPTA complexes containing N‐substituted Tetrazole scaffolds: Synthesis, characterization and Antiproliferative activity. Appl Organomet Chem 2017. [DOI: 10.1002/aoc.4179] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Poulami Mandal
- Department of Chemistry, School of Basic SciencesIndian Institute of Technology Indore Indore 453552 India
| | - Novina Malviya
- Department of Chemistry, School of Basic SciencesIndian Institute of Technology Indore Indore 453552 India
| | - Bidyut Kumar Kundu
- Department of Chemistry, School of Basic SciencesIndian Institute of Technology Indore Indore 453552 India
| | - Sandeep Singh Dhankhar
- Department of ChemistryIndian Institute of Technology Ropar Rupnagar 140001 Punjab India
| | - C.M. Nagaraja
- Department of ChemistryIndian Institute of Technology Ropar Rupnagar 140001 Punjab India
| | - Suman Mukhopadhyay
- Department of Chemistry, School of Basic SciencesIndian Institute of Technology Indore Indore 453552 India
- Centre for Bioscience and Biomedical Engineering (BSBE)Indian Institute of Technology Indore Indore 453552 India
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9
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Design and Synthesis of Potent in Vitro and in Vivo Anticancer Agents Based on 1-(3',4',5'-Trimethoxyphenyl)-2-Aryl-1H-Imidazole. Sci Rep 2016; 6:26602. [PMID: 27216165 PMCID: PMC4877593 DOI: 10.1038/srep26602] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 05/03/2016] [Indexed: 11/23/2022] Open
Abstract
A novel series of tubulin polymerization inhibitors, based on the 1-(3′,4′,5′-trimethoxyphenyl)-2-aryl-1H-imidazole scaffold and designed as cis-restricted combretastatin A-4 analogues, was synthesized with the goal of evaluating the effects of various patterns of substitution on the phenyl at the 2-position of the imidazole ring on biological activity. A chloro and ethoxy group at the meta- and para-positions, respectively, produced the most active compound in the series (4o), with IC50 values of 0.4-3.8 nM against a panel of seven cancer cell lines. Except in HL-60 cells, 4o had greater antiproliferative than CA-4, indicating that the 3′-chloro-4′-ethoxyphenyl moiety was a good surrogate for the CA-4 B-ring. Experiments carried out in a mouse syngenic model demonstrated high antitumor activity of 4o, which significantly reduced the tumor mass at a dose thirty times lower than that required for CA-4P, which was used as a reference compound. Altogether, our findings suggest that 4o is a promising anticancer drug candidate that warrants further preclinical evaluation.
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10
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Daswani VP, Ayesa U, Venegas B, Chong PLG. Concentration-Induced J-Aggregate Formation Causes a Biphasic Change in the Release of trans-Combretastatin A4 Disodium Phosphate from Archaeosomes and the Subsequent Cytotoxicity on Mammary Cancer Cells. Mol Pharm 2015; 12:3724-34. [DOI: 10.1021/acs.molpharmaceut.5b00500] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Varsha P. Daswani
- Department of Medical Genetics
and Molecular Biochemistry, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, United States
| | - Umme Ayesa
- Department of Medical Genetics
and Molecular Biochemistry, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, United States
| | - Berenice Venegas
- Department of Medical Genetics
and Molecular Biochemistry, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, United States
| | - Parkson Lee-Gau Chong
- Department of Medical Genetics
and Molecular Biochemistry, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, United States
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Scherer KM, Bisby RH, Botchway SW, Hadfield JA, Parker AW. Anticancer phototherapy using activation of E-combretastatins by two-photon-induced isomerization. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:051004. [PMID: 25347575 DOI: 10.1117/1.jbo.20.5.051004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 09/12/2014] [Indexed: 06/04/2023]
Abstract
The photoisomerization of relatively nontoxic E-combretastatins to clinically active Z-isomers is shown to occur in solution through both one- and two-photon excitations at 340 and 625 nm, respectively. The photoisomerization is also demonstrated to induce mammalian cell death by a two-photon absorption process at 625 nm. Unlike conventional photodynamic therapy (PDT), the mechanism of photoisomerization is oxygen-independent and active in hypoxic environments such as in tumors. The use of red or near-infrared (NIR) light for two-photon excitation allows greater tissue penetration than conventional UV one-photon excitation. The results provide a baseline for the development of a novel phototherapy that overcomes nondiscriminative systemic toxicity of Z-combretastatins and the limitations of PDT drugs that require the presence of oxygen to promote their activity, with the added benefits of two-photon red or NIR excitation for deeper tissue penetration.
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Affiliation(s)
- Kathrin M Scherer
- Research Complex at Harwell, Central Laser Facility, Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0FA, United KingdombUniversity of Salford, Biomedical Research Centre, Salford, Greater Manchester M5 4WT, United Kingdom
| | - Roger H Bisby
- University of Salford, Biomedical Research Centre, Salford, Greater Manchester M5 4WT, United Kingdom
| | - Stanley W Botchway
- Research Complex at Harwell, Central Laser Facility, Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0FA, United Kingdom
| | - John A Hadfield
- University of Salford, Biomedical Research Centre, Salford, Greater Manchester M5 4WT, United Kingdom
| | - Anthony W Parker
- Research Complex at Harwell, Central Laser Facility, Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0FA, United Kingdom
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12
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13
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Botchway SW, Scherer KM, Hook S, Stubbs CD, Weston E, Bisby RH, Parker AW. A series of flexible design adaptations to the Nikon E-C1 and E-C2 confocal microscope systems for UV, multiphoton and FLIM imaging. J Microsc 2015; 258:68-78. [PMID: 25664385 DOI: 10.1111/jmi.12218] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 12/17/2014] [Indexed: 12/16/2022]
Abstract
Multiphoton microscopy is widely employed in the life sciences using extrinsic fluorescence of low- and high-molecular weight labels with excitation and emission spectra in the visible and near infrared regions. For imaging of intrinsic and extrinsic fluorophores with excitation spectra in the ultraviolet region, multiphoton excitation with one- or two-colour lasers avoids the need for ultraviolet-transmitting excitation optics and has advantages in terms of optical penetration in the sample and reduced phototoxicity. Excitation and detection of ultraviolet emission around 300 nm and below in a typical inverted confocal microscope is more difficult and requires the use of expensive quartz optics including the objective. In this technical note we describe the adaptation of a commercial confocal microscope (Nikon, Japan E-C1 or E-C2) for versatile use with Ti-sapphire and OPO laser sources and the addition of a second detection channel that enables detection of ultraviolet fluorescence and increases detection sensitivity in a typical fluorescence lifetime imaging microscopy experiment. Results from some experiments with this setup illustrate the resulting capabilities.
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Affiliation(s)
- Stanley W Botchway
- Central Laser Facility, STFC, Rutherford Appleton Laboratory, Research Complex at Harwell, Harwell Oxford, Didcot, UK
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14
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Ghosh S, Chattoraj S, Mondal T, Bhattacharyya K. Dynamics in cytoplasm, nucleus, and lipid droplet of a live CHO cell: time-resolved confocal microscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:7975-7982. [PMID: 23705762 DOI: 10.1021/la400840n] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Different regions of a single live Chinese hamster ovary (CHO) cell are probed by time-resolved confocal microscopy. We used coumarin 153 (C153) as a probe. The dye localizes in the cytoplasm, nucleus, and lipid droplets, as is clearly revealed by the image. The fluorescence correlation spectroscopy (FCS) data shows that the microviscosity of lipid droplets is ~34 ± 3 cP. The microviscosities of nucleus and cytoplasm are found to be 13 ± 1 and 14.5 ± 1 cP, respectively. The average solvation time (<τs>) in the lipid droplets (3600 ± 50 ps) is slower than that in the nucleus (<τs> = 750 ± 50 ps) and cytoplasm (<τs> = 1100 ± 50 ps). From the position of emission maxima of C153, the polarity of the nucleus is estimated to be similar to that of a mixture containing 26% DMSO in triacetin (η ~ 11.2 cP, ε ~ 26.2). The cytoplasm resembles a mixture of 18% DMSO in triacetin (η ∼ 12.6 cP, ε ∼ 21.9). The polarity of lipid droplets is less than that of pure triacetin (η ~ 21.7 cP, ε ~ 7.11).
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Affiliation(s)
- Shirsendu Ghosh
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India
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15
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Cao J, Hu C, Liu F, Sun W, Fan J, Song F, Sun S, Peng X. Mechanism and Nature of the Different Viscosity Sensitivities of Hemicyanine Dyes with Various Heterocycles. Chemphyschem 2013; 14:1601-8. [DOI: 10.1002/cphc.201300049] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Indexed: 01/02/2023]
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