1
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Watson LS, Hughes J, Rafik ST, Muguruza AR, Girio PM, Akponasa SO, Rochford G, MacRobert AJ, Hodges NJ, Yaghini E, Pikramenou Z. Near infra-red luminescent osmium labelled gold nanoparticles for cellular imaging and singlet oxygen generation. NANOSCALE 2024; 16:16500-16509. [PMID: 39157997 PMCID: PMC11331564 DOI: 10.1039/d4nr01901f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Accepted: 08/06/2024] [Indexed: 08/20/2024]
Abstract
Osmium(II) complexes have attractive properties for potential theranostic agents given their anticancer activitiy, their redox potentials favourable for biological transformations within cancer cells and their luminescence in the near infrared (NIR) region. To achieve localised detection and delivery, gold nanoparticles (AuNP) provide an attractive scaffold to attach multiple luminescent agents on a single particle and provide a multimodal platform for detection and loaclaised delivery. We have developed 13 nm and 25 nm AuNP decorated with an osmium complex based on 1,10-phenantholine and surface active bipyridine ligands, OsPhenSS for live cell imaging and singlet oxygen generation, notated as OsPhenSS·AuNP13 and OsPhenSS·AuNP25. The AuNP designs not only allow versatile modalities for localisation of the probe but also water solubility for the osmium metal complex. The osmium decorated nanoparticles OsPhenSS·AuNP13 and OsPhenSS·AuNP25 display characteristic NIR luminescence from the osmium(II) 3MLCT at 785 nm in aqueous solutions with visible excitation. Upon incubation of the nanoparticles in lung cancer and breast carcinoma the luminescence signature of osmium and the gold reflectance reveal localisation in the cytoplasmic and perinuclear compartments. Excitation of the nanoparticles at 552 nm in the presence of a ROS indicator revealed a marked increase in the green fluorescence from the indicator, consistent with photo-induced ROS generation. The detection of singlet oxygen by time-resolved luminescence studies of the osmium and the nanoparticle probes further demonstrates the dual activity of the osmium-based nanoprobes for imaging and therapy. The introduction of gold nanoparticles for carrying osmium imaging probes allows a novel versatile strategy combining detection and localised therapies at the nanoscale.
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Affiliation(s)
- Luke S Watson
- School of Chemistry, University of Birmingham, Edgbaston, B15 2TT, UK.
| | - Joseph Hughes
- School of Chemistry, University of Birmingham, Edgbaston, B15 2TT, UK.
| | - Salma T Rafik
- Dept. of Surgical Biotechnology, Faculty of Medical Sciences, University College London, London, UK
- Department of Clinical Pharmacology, Faculty of Medicine, Alexandria University, Alexandria 21516, Egypt
| | - Asier R Muguruza
- School of Chemistry, University of Birmingham, Edgbaston, B15 2TT, UK.
| | - Patricia M Girio
- School of Chemistry, University of Birmingham, Edgbaston, B15 2TT, UK.
- Doctoral Training Centre in Physical Sciences for Health, University of Birmingham, Edgbaston, B15 2TT, UK
| | - Sarah O Akponasa
- School of Chemistry, University of Birmingham, Edgbaston, B15 2TT, UK.
- School of Biosciences, University of Birmingham, Edgbaston, B15 2TT, UK
| | - Garret Rochford
- School of Biosciences, University of Birmingham, Edgbaston, B15 2TT, UK
| | - Alexander J MacRobert
- Dept. of Surgical Biotechnology, Faculty of Medical Sciences, University College London, London, UK
| | - Nikolas J Hodges
- School of Biosciences, University of Birmingham, Edgbaston, B15 2TT, UK
| | - Elnaz Yaghini
- Dept. of Surgical Biotechnology, Faculty of Medical Sciences, University College London, London, UK
| | - Zoe Pikramenou
- School of Chemistry, University of Birmingham, Edgbaston, B15 2TT, UK.
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2
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Lee LCC, Lo KKW. Shining New Light on Biological Systems: Luminescent Transition Metal Complexes for Bioimaging and Biosensing Applications. Chem Rev 2024; 124:8825-9014. [PMID: 39052606 PMCID: PMC11328004 DOI: 10.1021/acs.chemrev.3c00629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2024]
Abstract
Luminescence imaging is a powerful and versatile technique for investigating cell physiology and pathology in living systems, making significant contributions to life science research and clinical diagnosis. In recent years, luminescent transition metal complexes have gained significant attention for diagnostic and therapeutic applications due to their unique photophysical and photochemical properties. In this Review, we provide a comprehensive overview of the recent development of luminescent transition metal complexes for bioimaging and biosensing applications, with a focus on transition metal centers with a d6, d8, and d10 electronic configuration. We elucidate the structure-property relationships of luminescent transition metal complexes, exploring how their structural characteristics can be manipulated to control their biological behavior such as cellular uptake, localization, biocompatibility, pharmacokinetics, and biodistribution. Furthermore, we introduce the various design strategies that leverage the interesting photophysical properties of luminescent transition metal complexes for a wide variety of biological applications, including autofluorescence-free imaging, multimodal imaging, organelle imaging, biological sensing, microenvironment monitoring, bioorthogonal labeling, bacterial imaging, and cell viability assessment. Finally, we provide insights into the challenges and perspectives of luminescent transition metal complexes for bioimaging and biosensing applications, as well as their use in disease diagnosis and treatment evaluation.
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Affiliation(s)
- Lawrence Cho-Cheung Lee
- Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, P. R. China
- Laboratory for Synthetic Chemistry and Chemical Biology Limited, Units 1503-1511, 15/F, Building 17W, Hong Kong Science Park, New Territories, Hong Kong, P. R. China
| | - Kenneth Kam-Wing Lo
- Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, P. R. China
- State Key Laboratory of Terahertz and Millimeter Waves, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, P. R. China
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3
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Peterková K, Stitch M, Boota RZ, Scattergood PA, Elliott PIP, Towrie M, Podbevšek P, Plavec J, Quinn SJ. G-Quadruplex Binding of an NIR Emitting Osmium Polypyridyl Probe Revealed by Solution NMR and Time-Resolved Infrared Studies. Chemistry 2023; 29:e202203250. [PMID: 36398697 DOI: 10.1002/chem.202203250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/11/2022] [Accepted: 11/17/2022] [Indexed: 11/19/2022]
Abstract
G-quadruplexes are emerging targets in cancer research and understanding how diagnostic probes bind to DNA G-quadruplexes in solution is critical to the development of new molecular tools. In this study the binding of an enantiopure NIR emitting [Os(TAP)2 (dppz)]2+ complex to different G-quadruplex structures formed by human telomer (hTel) and cMYC sequences in solution is reported. The combination of NMR and time-resolved infrared spectroscopic techniques reveals the sensitivity of the emission response to subtle changes in the binding environment of the complex. Similar behaviour is also observed for the related complex [Os(TAP)2 (dppp2)]2+ upon quadruplex binding.
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Affiliation(s)
- Kateřina Peterková
- Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19, 1000, Ljubljana, Slovenia
- National Centre for Biomolecular Research Faculty of Science, Masaryk University, Kamenice 5, 62500, Brno, Czechia
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, 1000, Ljubljana, Slovenia
| | - Mark Stitch
- School of Chemistry, University College Dublin, Dublin, 4, Ireland
| | - Rayhaan Z Boota
- Department of Chemical Sciences, School of Applied Sciences University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, UK
| | - Paul A Scattergood
- Department of Chemical Sciences, School of Applied Sciences University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, UK
| | - Paul I P Elliott
- Department of Chemical Sciences, School of Applied Sciences University of Huddersfield, Queensgate, Huddersfield, HD1 3DH, UK
| | - Michael Towrie
- Rutherford Appleton Laboratory, STFC, Harwell Campus, OX11 0FA, UK
| | - Peter Podbevšek
- Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19, 1000, Ljubljana, Slovenia
| | - Janez Plavec
- Slovenian NMR Center, National Institute of Chemistry, Hajdrihova 19, 1000, Ljubljana, Slovenia
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, 1000, Ljubljana, Slovenia
- EN-FIST Centre of Excellence Trg OF 13, 1000, Ljubljana, Slovenia
| | - Susan J Quinn
- School of Chemistry, University College Dublin, Dublin, 4, Ireland
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4
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Stitch M, Boota RZ, Chalkley AS, Keene TD, Simpson JC, Scattergood PA, Elliott PIP, Quinn SJ. Photophysical Properties and DNA Binding of Two Intercalating Osmium Polypyridyl Complexes Showing Light-Switch Effects. Inorg Chem 2022; 61:14947-14961. [PMID: 36094851 PMCID: PMC9516684 DOI: 10.1021/acs.inorgchem.2c01231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
The synthesis and
photophysical characterization of two osmium(II)
polypyridyl complexes, [Os(TAP)2dppz]2+ (1) and [Os(TAP)2dppp2]2+ (2) containing dppz (dipyrido[3,2-a:2′,3′-c]phenazine) and dppp2 (pyrido[2′,3′:5,6]pyrazino[2,3-f][1,10]phenanthroline) intercalating ligands and TAP (1,4,5,8-tetraazaphenanthrene)
ancillary ligands, are reported. The complexes exhibit complex electrochemistry
with five distinct reductive redox couples, the first of which is
assigned to a TAP-based process. The complexes emit in the near-IR
(1 at 761 nm and 2 at 740 nm) with lifetimes
of >35 ns with a low quantum yield of luminescence in aqueous solution
(∼0.25%). The Δ and Λ enantiomers of 1 and 2 are found to bind to natural DNA and with AT
and GC oligodeoxynucleotides with high affinities. In the presence
of natural DNA, the visible absorption spectra are found to display
significant hypochromic shifts, which is strongly evident for the
ligand-centered π–π* dppp2 transition at 355 nm,
which undergoes 46% hypochromism. The emission of both complexes increases
upon DNA binding, which is observed to be sensitive to the Δ
or Λ enantiomer and the DNA composition. A striking result is
the sensitivity of Λ-2 to the presence of AT DNA,
where a 6-fold enhancement of luminescence is observed and reflects
the nature of the binding for the enantiomer and the protection from
solution. Thermal denaturation studies show that both complexes are
found to stabilize natural DNA. Finally, cellular studies show that
the complexes are internalized by cultured mammalian cells and localize
in the nucleus. Osmium(II)
polypyridyl complexes comprising extended dipyrido[3,2-a:2′,3′-c]phenazine (1) and pyrido[2′,3′:5,6]pyrazino[2,3-f][1,10]phenanthroline (2) intercalating ligands
are shown to be effective DNA binders accompanied by enhanced near-IR
emission. The emission response to B-DNA is found to be sensitive
to the enantiomer and the composition of DNA, with greater emission
observed for AT-rich sequences. Thermal denaturation studies show
that both complexes stabilize natural DNA. Cellular studies show that
the complexes are internalized by cultured mammalian cells and localize
in the nucleus.
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Affiliation(s)
- Mark Stitch
- School of Chemistry, University College Dublin, Dublin 4 D04 V1W8, Ireland
| | - Rayhaan Z Boota
- Department of Chemical Sciences, School of Applied Sciences University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Alannah S Chalkley
- Cell Screening Laboratory, School of Biology and Environmental Science, University College Dublin, Dublin 4 D04 V1W8, Ireland
| | - Tony D Keene
- School of Chemistry, University College Dublin, Dublin 4 D04 V1W8, Ireland
| | - Jeremy C Simpson
- Cell Screening Laboratory, School of Biology and Environmental Science, University College Dublin, Dublin 4 D04 V1W8, Ireland
| | - Paul A Scattergood
- Department of Chemical Sciences, School of Applied Sciences University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Paul I P Elliott
- Department of Chemical Sciences, School of Applied Sciences University of Huddersfield, Queensgate, Huddersfield HD1 3DH, U.K
| | - Susan J Quinn
- School of Chemistry, University College Dublin, Dublin 4 D04 V1W8, Ireland
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5
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Metal Peptide Conjugates in Cell and Tissue Imaging and Biosensing. Top Curr Chem (Cham) 2022; 380:30. [PMID: 35701677 PMCID: PMC9197911 DOI: 10.1007/s41061-022-00384-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Accepted: 05/10/2022] [Indexed: 11/05/2022]
Abstract
Metal complex luminophores have seen dramatic expansion in application as imaging probes over the past decade. This has been enabled by growing understanding of methods to promote their cell permeation and intracellular targeting. Amongst the successful approaches that have been applied in this regard is peptide-facilitated delivery. Cell-permeating or signal peptides can be readily conjugated to metal complex luminophores and have shown excellent response in carrying such cargo through the cell membrane. In this article, we describe the rationale behind applying metal complexes as probes and sensors in cell imaging and outline the advantages to be gained by applying peptides as the carrier for complex luminophores. We describe some of the progress that has been made in applying peptides in metal complex peptide-driven conjugates as a strategy for cell permeation and targeting of transition metal luminophores. Finally, we provide key examples of their application and outline areas for future progress.
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6
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Dröge F, Noakes FF, Archer SA, Sreedharan S, Raza A, Robertson CC, MacNeil S, Haycock JW, Carson H, Meijer AJHM, Smythe CGW, Bernardino de la Serna J, Dietzek-Ivanšić B, Thomas JA. A Dinuclear Osmium(II) Complex Near-Infrared Nanoscopy Probe for Nuclear DNA. J Am Chem Soc 2021; 143:20442-20453. [PMID: 34808044 DOI: 10.1021/jacs.1c10325] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
With the aim of developing photostable near-infrared cell imaging probes, a convenient route to the synthesis of heteroleptic OsII complexes containing the Os(TAP)2 fragment is reported. This method was used to synthesize the dinuclear OsII complex, [{Os(TAP)2}2tpphz]4+ (where tpphz = tetrapyrido[3,2-a:2',3'-c:3″,2''-h:2‴,3'''-j]phenazine and TAP = 1,4,5,8- tetraazaphenanthrene). Using a combination of resonance Raman and time-resolved absorption spectroscopy, as well as computational studies, the excited state dynamics of the new complex were dissected. These studies revealed that, although the complex has several close lying excited states, its near-infrared, NIR, emission (λmax = 780 nm) is due to a low-lying Os → TAP based 3MCLT state. Cell-based studies revealed that unlike its RuII analogue, the new complex is neither cytotoxic nor photocytotoxic. However, as it is highly photostable as well as live-cell permeant and displays NIR luminescence within the biological optical window, its properties make it an ideal probe for optical microscopy, demonstrated by its use as a super-resolution NIR STED probe for nuclear DNA.
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Affiliation(s)
- Fabian Dröge
- Institute of Physical Chemistry, Helmholtzweg 4, 07743 Jena, Germany; Institute of Photonic Technology Jena e.V., Albert-Einstein-Straße 9, 07749 Jena, Germany
| | | | | | | | | | | | | | | | | | | | | | - Jorge Bernardino de la Serna
- Central Laser Facility, Rutherford Appleton Laboratory, Research Complex at Harwell, Science and Technology Facilities Council, Harwell-Oxford, Didcot OX11 0QX, United Kingdom; National Heart and Lung Institute, Faculty of Medicine, Imperial College London, Sir Alexander Fleming Building, Exhibition Road, London SW7 2AZ, United Kingdom
| | - Benjamin Dietzek-Ivanšić
- Institute of Physical Chemistry, Helmholtzweg 4, 07743 Jena, Germany; Institute of Photonic Technology Jena e.V., Albert-Einstein-Straße 9, 07749 Jena, Germany
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7
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Holden L, Burke CS, Cullinane D, Keyes TE. Strategies to promote permeation and vectorization, and reduce cytotoxicity of metal complex luminophores for bioimaging and intracellular sensing. RSC Chem Biol 2021; 2:1021-1049. [PMID: 34458823 PMCID: PMC8341117 DOI: 10.1039/d1cb00049g] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 04/30/2021] [Indexed: 12/19/2022] Open
Abstract
Transition metal luminophores are emerging as important tools for intracellular imaging and sensing. Their putative suitability for such applications has long been recognised but poor membrane permeability and cytotoxicity were significant barriers that impeded early progress. In recent years, numerous effective routes to overcoming these issues have been reported, inspired in part, by advances and insights from the pharmaceutical and drug delivery domains. In particular, the conjugation of biomolecules but also other less natural synthetic species, from a repertoire of functional motifs have granted membrane permeability and cellular targeting. Such motifs can also reduce cytotoxicity of transition metal complexes and offer a valuable avenue to circumvent such problems leading to promising metal complex candidates for application in bioimaging, sensing and diagnostics. The advances in metal complex probes permeability/targeting are timely, as, in parallel, over the past two decades significant technological advances in luminescence imaging have occurred. In particular, super-resolution imaging is enormously powerful but makes substantial demands of its imaging contrast agents and metal complex luminophores frequently possess the photophysical characteristics to meet these demands. Here, we review some of the key vectors that have been conjugated to transition metal complex luminophores to promote their use in intra-cellular imaging applications. We evaluate some of the most effective strategies in terms of membrane permeability, intracellular targeting and what impact these approaches have on toxicity and phototoxicity which are important considerations in a luminescent contrast or sensing agent.
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Affiliation(s)
- Lorcan Holden
- School of Chemical Sciences, and National Centre for Sensor Research Dublin City University Dublin 9 Ireland
| | - Christopher S Burke
- School of Chemical Sciences, and National Centre for Sensor Research Dublin City University Dublin 9 Ireland
| | - David Cullinane
- School of Chemical Sciences, and National Centre for Sensor Research Dublin City University Dublin 9 Ireland
| | - Tia E Keyes
- School of Chemical Sciences, and National Centre for Sensor Research Dublin City University Dublin 9 Ireland
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8
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Gkika K, Noorani S, Walsh N, Keyes TE. Os(II)-Bridged Polyarginine Conjugates: The Additive Effects of Peptides in Promoting or Preventing Permeation in Cells and Multicellular Tumor Spheroids. Inorg Chem 2021; 60:8123-8134. [PMID: 33978399 PMCID: PMC8277133 DOI: 10.1021/acs.inorgchem.1c00769] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Indexed: 12/05/2022]
Abstract
The preparation of two polyarginine conjugates of the complex Os(II) [bis-(4'-(4-carboxyphenyl)-2,2':6',2″-terpyridine)] [Os-(Rn)2]x+ (n = 4 and 8; x = 10 and 18) is reported, to explore whether the R8 peptide sequence that promotes cell uptake requires a contiguous amino acid sequence for membrane permeation or if this can be accomplished in a linearly bridged structure with the additive effect of shorter peptide sequences. The conjugates exhibit NIR emission centered at 754 nm and essentially oxygen-insensitive emission with a lifetime of 89 ns in phosphate-buffered saline. The uptake, distribution, and cytotoxicity of the parent complex and peptide derivatives were compared in 2D cell monolayers and a three-dimensional (3D) multicellular tumor spheroid (MCTS) model. Whereas, the bis-octaarginine sequences were impermeable to cells and spheroids, and the bis-tetraarginine conjugate showed excellent cellular uptake and accumulation in two 2D monolayer cell lines and remarkable in-depth penetration of 3D MCTSs of pancreatic cancer cells. Overall, the data indicates that cell permeability can be promoted via non-contiguous sequences of arginine residues bridged across the metal centre.
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Affiliation(s)
- Karmel
S. Gkika
- School
of Chemical Sciences, National Centre for Sensor Research, Dublin City University, Dublin 9, Ireland
| | - Sara Noorani
- School
of Biotechnology, National Institute for Cellular Biotechnology, Dublin City University, Dublin 9, Ireland
| | - Naomi Walsh
- School
of Biotechnology, National Institute for Cellular Biotechnology, Dublin City University, Dublin 9, Ireland
| | - Tia E. Keyes
- School
of Chemical Sciences, National Centre for Sensor Research, Dublin City University, Dublin 9, Ireland
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9
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Machado JF, Correia JDG, Morais TS. Emerging Molecular Receptors for the Specific-Target Delivery of Ruthenium and Gold Complexes into Cancer Cells. Molecules 2021; 26:3153. [PMID: 34070457 PMCID: PMC8197480 DOI: 10.3390/molecules26113153] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 05/21/2021] [Accepted: 05/24/2021] [Indexed: 12/19/2022] Open
Abstract
Cisplatin and derivatives are highly effective in the treatment of a wide range of cancer types; however, these metallodrugs display low selectivity, leading to severe side effects. Additionally, their administration often results in the development of chemoresistance, which ultimately results in therapeutic failure. This scenario triggered the study of other transition metals with innovative pharmacological profiles as alternatives to platinum, ruthenium- (e.g., KP1339 and NAMI-A) and gold-based (e.g., Auranofin) complexes being among the most advanced in terms of clinical evaluation. Concerning the importance of improving the in vivo selectivity of metal complexes and the current relevance of ruthenium and gold metals, this review article aims to survey the main research efforts made in the past few years toward the design and biological evaluation of target-specific ruthenium and gold complexes. Herein, we give an overview of the inorganic and organometallic molecules conjugated to different biomolecules for targeting membrane proteins, namely cell adhesion molecules, G-protein coupled receptors, and growth factor receptors. Complexes that recognize the progesterone receptors or other targets involved in metabolic pathways such as glucose transporters are discussed as well. Finally, we describe some complexes aimed at recognizing cell organelles or compartments, mitochondria being the most explored. The few complexes addressing targeted gene therapy are also presented and discussed.
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Affiliation(s)
- João Franco Machado
- Centro de Química Estrutural and Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisbon, Portugal;
- Centro de Ciências e Tecnologias Nucleares and Departamento de Engenharia e Ciências Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139, 7), 2695-066 Bobadela LRS, Portugal
| | - João D. G. Correia
- Centro de Ciências e Tecnologias Nucleares and Departamento de Engenharia e Ciências Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10 (km 139, 7), 2695-066 Bobadela LRS, Portugal
| | - Tânia S. Morais
- Centro de Química Estrutural and Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisbon, Portugal;
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10
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Shi H, Lou J, Lin S, Wang Y, Hu Y, Zhang P, Liu Y, Zhang Q. Diatom-like silica-protein nanocomposites for sustained drug delivery of ruthenium polypyridyl complexes. J Inorg Biochem 2021; 221:111489. [PMID: 34000586 DOI: 10.1016/j.jinorgbio.2021.111489] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 04/28/2021] [Accepted: 05/08/2021] [Indexed: 01/03/2023]
Abstract
Inspired by the unique glass cell wall of diatom, we design a new nanostructure of human serum albumin nanoparticle (HSANP) coated with silica (HSA/SiO2), which consists of a core-satellite assembly of small silica nanoparticles on a single HSANP. The HSA/SiO2 nanoparticles are used for delivering ruthenium polypyridyl complexes into cells. The silica coating increases the Ru loading efficiency, and prevents the burst release of Ru from HSA/SiO2. The Ru release rate can be controlled by adjusting the amount of coated silica on HSANP, affording a drug delivery system with controlled drug release rate. The Ru-HSA/SiO2 nanoparticles show high stability in physiological condition, and significantly increase the Ru uptake into cells, which proceeds via clathrin-mediated endocytosis into the lysosomes. The silica coating takes no effect on the fluorescence intensity and ROS generation of loaded Ru in HSA/SiO2. Furthermore, Ru4-HSA/SiO2 exhibit weak cytotoxicity in dark, however, the nanodrug can be activated by light irradiation and generate ROS to damage cells, thus achieving an excellent photodynamic therapy efficiency. Therefore, the diatom-like nanostructure can function as sustained drug delivery nanocarrier of ruthenium polypyridyl complex and can be used for bioimaging and photodynamic therapy.
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Affiliation(s)
- Hongdong Shi
- Graphene Composite Research Center, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong 518060, China
| | - Jingxue Lou
- Graphene Composite Research Center, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong 518060, China
| | - Simin Lin
- Graphene Composite Research Center, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong 518060, China
| | - Yi Wang
- Graphene Composite Research Center, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong 518060, China
| | - Yatao Hu
- Graphene Composite Research Center, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong 518060, China
| | - Pingyu Zhang
- Graphene Composite Research Center, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong 518060, China
| | - Yangzhong Liu
- CAS Key Laboratory of Soft Matter Chemistry, CAS High Magnetic Field Laboratory, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Qianling Zhang
- Graphene Composite Research Center, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, Guangdong 518060, China.
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11
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Ravetz B, Tay NES, Joe CL, Sezen-Edmonds M, Schmidt MA, Tan Y, Janey JM, Eastgate MD, Rovis T. Development of a Platform for Near-Infrared Photoredox Catalysis. ACS CENTRAL SCIENCE 2020; 6:2053-2059. [PMID: 33274281 PMCID: PMC7706074 DOI: 10.1021/acscentsci.0c00948] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Indexed: 05/05/2023]
Abstract
Over the past decade, chemists have embraced visible-light photoredox catalysis due to its remarkable ability to activate small molecules. Broadly, these methods employ metal complexes or organic dyes to convert visible light into chemical energy. Unfortunately, the excitation of widely utilized Ru and Ir chromophores is energetically wasteful as ∼25% of light energy is lost thermally before being quenched productively. Hence, photoredox methodologies require high-energy, intense light to accommodate said catalytic inefficiency. Herein, we report photocatalysts which cleanly convert near-infrared (NIR) and deep red (DR) light into chemical energy with minimal energetic waste. We leverage the strong spin-orbit coupling (SOC) of Os(II) photosensitizers to directly access the excited triplet state (T1) with NIR or DR irradiation from the ground state singlet (S0). Through strategic catalyst design, we access a wide range of photoredox, photopolymerization, and metallaphotoredox reactions which usually require 15-50% higher excitation energy. Finally, we demonstrate superior light penetration and scalability of NIR photoredox catalysis through a mole-scale arene trifluoromethylation in a batch reactor.
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Affiliation(s)
- Benjamin
D. Ravetz
- Department
of Chemistry, Columbia University, New York, New York 10027, United States
| | - Nicholas E. S. Tay
- Department
of Chemistry, Columbia University, New York, New York 10027, United States
| | - Candice L. Joe
- Chemical
Process Development, Bristol Myers Squibb, 1 Squibb Drive, New Brunswick, New Jersey 08903, United States
- E-mail:
| | - Melda Sezen-Edmonds
- Chemical
Process Development, Bristol Myers Squibb, 1 Squibb Drive, New Brunswick, New Jersey 08903, United States
| | - Michael A. Schmidt
- Chemical
Process Development, Bristol Myers Squibb, 1 Squibb Drive, New Brunswick, New Jersey 08903, United States
| | - Yichen Tan
- Chemical
Process Development, Bristol Myers Squibb, 1 Squibb Drive, New Brunswick, New Jersey 08903, United States
| | - Jacob M. Janey
- Chemical
Process Development, Bristol Myers Squibb, 1 Squibb Drive, New Brunswick, New Jersey 08903, United States
| | - Martin D. Eastgate
- Chemical
Process Development, Bristol Myers Squibb, 1 Squibb Drive, New Brunswick, New Jersey 08903, United States
| | - Tomislav Rovis
- Department
of Chemistry, Columbia University, New York, New York 10027, United States
- E-mail:
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12
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Schneider KRA, Chettri A, Cole HD, Reglinski K, Brückmann J, Roque JA, Stumper A, Nauroozi D, Schmid S, Lagerholm CB, Rau S, Bäuerle P, Eggeling C, Cameron CG, McFarland SA, Dietzek B. Intracellular Photophysics of an Osmium Complex bearing an Oligothiophene Extended Ligand. Chemistry 2020; 26:14844-14851. [PMID: 32761643 PMCID: PMC7704931 DOI: 10.1002/chem.202002667] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 07/26/2020] [Indexed: 12/27/2022]
Abstract
This contribution describes the excited-state properties of an Osmium-complex when taken up into human cells. The complex 1 [Os(bpy)2 (IP-4T)](PF6 )2 with bpy=2,2'-bipyridine and IP-4T=2-{5'-[3',4'-diethyl-(2,2'-bithien-5-yl)]-3,4-diethyl-2,2'-bithiophene}imidazo[4,5-f][1,10]phenanthroline) can be discussed as a candidate for photodynamic therapy in the biological red/NIR window. The complex is taken up by MCF7 cells and localizes rather homogeneously within in the cytoplasm. To detail the sub-ns photophysics of 1, comparative transient absorption measurements were carried out in different solvents to derive a model of the photoinduced processes. Key to rationalize the excited-state relaxation is a long-lived 3 ILCT state associated with the oligothiophene chain. This model was then tested with the complex internalized into MCF7 cells, since the intracellular environment has long been suspected to take big influence on the excited state properties. In our study of 1 in cells, we were able to show that, though the overall model remained the same, the excited-state dynamics are affected strongly by the intracellular environment. Our study represents the first in depth correlation towards ex-vivo and in vivo ultrafast spectroscopy for a possible photodrug.
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Affiliation(s)
- Kilian R. A. Schneider
- Department Functional Interfaces (K.R.A.S., A.C., B.D.)Department Biophysical Imaging (K.R., C.E.)Leibniz Institute of Photonic Technology (IPHT) e. V.Albert-Einstein-Straße 907745JenaGermany
- Institute of Physical Chemistry and Abbe Center of PhotonicsFriedrich-Schiller-University JenaHelmholtzweg 407743JenaGermany
| | - Avinash Chettri
- Department Functional Interfaces (K.R.A.S., A.C., B.D.)Department Biophysical Imaging (K.R., C.E.)Leibniz Institute of Photonic Technology (IPHT) e. V.Albert-Einstein-Straße 907745JenaGermany
- Institute of Physical Chemistry and Abbe Center of PhotonicsFriedrich-Schiller-University JenaHelmholtzweg 407743JenaGermany
| | - Houston D. Cole
- Department of Chemistry and BiochemistryThe University of Texas at ArlingtonArlingtonTX76019-0065USA
| | - Katharina Reglinski
- Department Functional Interfaces (K.R.A.S., A.C., B.D.)Department Biophysical Imaging (K.R., C.E.)Leibniz Institute of Photonic Technology (IPHT) e. V.Albert-Einstein-Straße 907745JenaGermany
- Institute of Applied Optic and BiophysicsFriedrich-Schiller University JenaMax-Wien-Platz 107743JenaGermany
- University Hospital JenaBachstraße 1807743JenaGermany
| | - Jannik Brückmann
- Institute of Inorganic Chemistry IUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
| | - John A. Roque
- Department of Chemistry and BiochemistryThe University of Texas at ArlingtonArlingtonTX76019-0065USA
- Department of Chemistry and BiochemistryThe University of North Carolina at GreensboroGreensboroNorth Carolina27402USA
| | - Anne Stumper
- Institute of Inorganic Chemistry IUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
| | - Djawed Nauroozi
- Institute of Inorganic Chemistry IUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
| | - Sylvia Schmid
- Institute of Organic Chemistry II and Advanced MaterialsUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
| | | | - Sven Rau
- Institute of Inorganic Chemistry IUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
| | - Peter Bäuerle
- Institute of Organic Chemistry II and Advanced MaterialsUlm UniversityAlbert-Einstein-Allee 1189081UlmGermany
| | - Christian Eggeling
- Department Functional Interfaces (K.R.A.S., A.C., B.D.)Department Biophysical Imaging (K.R., C.E.)Leibniz Institute of Photonic Technology (IPHT) e. V.Albert-Einstein-Straße 907745JenaGermany
- Institute of Applied Optic and BiophysicsFriedrich-Schiller University JenaMax-Wien-Platz 107743JenaGermany
- <MRC Human Immunology Unit & Wolfson Imaging Center OxfordHeadley WayOxfordOX3 9DSUK
| | - Colin G. Cameron
- Department of Chemistry and BiochemistryThe University of Texas at ArlingtonArlingtonTX76019-0065USA
| | - Sherri A. McFarland
- Department of Chemistry and BiochemistryThe University of Texas at ArlingtonArlingtonTX76019-0065USA
| | - Benjamin Dietzek
- Department Functional Interfaces (K.R.A.S., A.C., B.D.)Department Biophysical Imaging (K.R., C.E.)Leibniz Institute of Photonic Technology (IPHT) e. V.Albert-Einstein-Straße 907745JenaGermany
- Institute of Physical Chemistry and Abbe Center of PhotonicsFriedrich-Schiller-University JenaHelmholtzweg 407743JenaGermany
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13
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Smitten KL, Scattergood PA, Kiker C, Thomas JA, Elliott PIP. Triazole-based osmium(ii) complexes displaying red/near-IR luminescence: antimicrobial activity and super-resolution imaging. Chem Sci 2020; 11:8928-8935. [PMID: 34123147 PMCID: PMC8163367 DOI: 10.1039/d0sc03563g] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2020] [Accepted: 08/06/2020] [Indexed: 12/15/2022] Open
Abstract
Cellular uptake, luminescence imaging and antimicrobial activity against clinically relevant methicillin-resistant S. aureus (MRSA) bacteria are reported. The osmium(ii) complexes [Os(N^N)3]2+ (N^N = 1-benzyl-4-(pyrid-2-yl)-1,2,3-triazole (1 2+); 1-benzyl-4-(pyrimidin-2-yl)-1,2,3-triazole (2 2+); 1-benzyl-4-(pyrazin-2-yl)-1,2,3-triazole (3 2+)) were prepared and isolated as the chloride salts of their meridional and facial isomers. The complexes display prominent spin-forbidden ground state to triplet metal-to-ligand charge transfer (3MLCT) state absorption bands enabling excitation as low as 600 nm for fac/mer-3 2+ and observation of emission in aqueous solution in the deep-red/near-IR regions of the spectrum. Cellular uptake studies within MRSA cells show antimicrobial activity for 1 2+ and 2 2+ with greater toxicity for the meridional isomers in each case and mer-1 2+ showing the greatest potency (32 μg mL-1 in defined minimal media). Super-resolution imaging experiments demonstrate binding of mer- and fac-1 2+ to bacterial DNA with high Pearson's colocalisation coefficients (up to 0.95 using DAPI). Phototoxicity studies showed the complexes exhibited a higher antimicrobial activity upon irradiation with light.
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Affiliation(s)
- Kirsty L Smitten
- Department of Chemistry, University of Sheffield Brook Hill Sheffield S3 7HF UK
| | - Paul A Scattergood
- Department of Chemistry & Centre for Functional Materials, University of Huddersfield Queensgate Huddersfield HD1 3DH UK
| | - Charlotte Kiker
- Department of Chemistry, University of Sheffield Brook Hill Sheffield S3 7HF UK
| | - Jim A Thomas
- Department of Chemistry, University of Sheffield Brook Hill Sheffield S3 7HF UK
| | - Paul I P Elliott
- Department of Chemistry & Centre for Functional Materials, University of Huddersfield Queensgate Huddersfield HD1 3DH UK
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14
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Lee LCC, Tsang AWY, Liu HW, Lo KKW. Photofunctional Cyclometalated Iridium(III) Polypyridine Complexes Bearing a Perfluorobiphenyl Moiety for Bioconjugation, Bioimaging, and Phototherapeutic Applications. Inorg Chem 2020; 59:14796-14806. [DOI: 10.1021/acs.inorgchem.0c01343] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Lawrence Cho-Cheung Lee
- Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Hong Kong, P. R. China
| | - Ada Wun-Yu Tsang
- Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Hong Kong, P. R. China
| | - Hua-Wei Liu
- Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Hong Kong, P. R. China
| | - Kenneth Kam-Wing Lo
- Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Hong Kong, P. R. China
- State Key Laboratory of Terahertz and Millimeter Waves, City University of Hong Kong, Tat Chee Avenue, Hong Kong, P. R. China
- Center of Functional Photonics, City University of Hong Kong, Tat Chee Avenue, Hong Kong, P. R. China
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15
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Gkika KS, Byrne A, Keyes TE. Mitochondrial targeted osmium polypyridyl probe shows concentration dependent uptake, localisation and mechanism of cell death. Dalton Trans 2020; 48:17461-17471. [PMID: 31513202 DOI: 10.1039/c9dt02967b] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A symmetric osmium(ii) [bis-(4'-(4-carboxyphenyl)-2,2':6',2''-terpyridine)] was prepared and conjugated to two mitochondrial-targeting peptide sequences; FrFKFrFK (r = d-arginine). The parent and conjugate complexes showed strong near infra-red emission centred at λmax 745 nm that was modestly oxygen dependent in the case of the parent and oxygen independent in the case of the conjugate, attributed in the latter case, surprisingly, to a shorter emission lifetime of the conjugate compared to the parent. Confocal fluorescence imaging of sub-live HeLa and MCF 7 cells showed the parent complex was cell impermeable whereas the conjugate was rapidly internalised into the cell and distributed in a concentration dependent manner. At concentrations below approximately 30 μmol, the conjugate localised to the mitochondria of both cell types where it was observed to trigger apoptosis induced by the collapse of the mitochondrial membrane potential (MPP). At concentrations exceeding 30 μmol the conjugate was similarly internalised rapidly but distributed throughout the cell, including to the nucleus and nucleolus. At these concentrations, it was observed to precipitate a caspase-dependent apoptotic pathway. The combination of concentration dependent organelle targeting, NIR emission coincident with the biological window, and distribution dependent cytotoxicity offers an interesting approach to theranostics with the possibility of eliciting site dependent therapeutic effect whilst monitoring the therapeutic effect with luminescence imaging.
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Affiliation(s)
- Karmel Sofia Gkika
- School of Chemical Sciences, National Centre for Sensor Research, Dublin City University, Glasnevin, Dublin 9, Ireland.
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16
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Cullinane D, Gkika KS, Byrne A, Keyes TE. Photostable NIR emitting ruthenium(II) conjugates; uptake and biological activity in live cells. J Inorg Biochem 2020; 207:111032. [PMID: 32311630 DOI: 10.1016/j.jinorgbio.2020.111032] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 02/11/2020] [Accepted: 02/12/2020] [Indexed: 01/19/2023]
Abstract
A photostable Ru(2,2-biquinoline)2(3-(2-pyridyl)-5-(4-carboxyphenyl)-1,2,4-triazolate) (Ru(biq)2(trzbenzCOOH)) complex that exhibits near-infrared (NIR) emission centred at 786 nm is reported. The parent complex was conjugated via amide coupling to a cell-penetrating peptide sequence octa-arginine (R8), and two signal peptide sequences; the nuclear localizing sequence (NLS) VQRKRQKLMP and the mitochondria penetrating peptide (MPP) FrFKFrFK(Ac) (r = D isomer of arginine, Ac = terminal lysine amine acetyl blocked). Notably, none of the peptide conjugates were cell-permeable as chloride salts but efficient and rapid membrane permeation was observed post ion exchange with perchlorate counterion. Also, surprisingly, all three peptide conjugates exhibited potent dark cytotoxicity in both CHO and HeLa cell lines. The peptide conjugates induce cell death through a caspase dependent apoptotic pathway. At the minimum concentration of dye (approx. 15 μM) required for cell imaging, only 20% of the cells were viable after a 24 h incubation period. To overcome cytotoxicity, the parent complex was PEGylated; this dramatically decreased cytotoxicity, where 50% of cells were viable even at 150 μM concentration after 24 h. Confocal luminescence microscopy indicated that all four bioconjugates, peptides in perchlorate form and polyethylene glycol (PEG) in chloride form, were rapidly internalized within the cell. However, interestingly the precise localisation by the signal peptides observed in related complexes was not observed here and the peptide conjugates were unsuitable as luminescent probes for cell microscopy due to their high cell toxicity. The poor targeting of signal peptides in this instance is attributed to the high lipophilicity of the metal centre.
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Affiliation(s)
- David Cullinane
- School of Chemical Sciences, National Centre for Sensor Research, Dublin City University, Dublin 9, Ireland
| | - Karmel Sofia Gkika
- School of Chemical Sciences, National Centre for Sensor Research, Dublin City University, Dublin 9, Ireland
| | - Aisling Byrne
- School of Chemical Sciences, National Centre for Sensor Research, Dublin City University, Dublin 9, Ireland
| | - Tia E Keyes
- School of Chemical Sciences, National Centre for Sensor Research, Dublin City University, Dublin 9, Ireland.
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17
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Huang R, Feng FP, Huang CH, Mao L, Tang M, Yan ZY, Shao B, Qin L, Xu T, Xue YH, Zhu BZ. Chiral Os(II) Polypyridyl Complexes as Enantioselective Nuclear DNA Imaging Agents Especially Suitable for Correlative High-Resolution Light and Electron Microscopy Studies. ACS APPLIED MATERIALS & INTERFACES 2020; 12:3465-3473. [PMID: 31913004 DOI: 10.1021/acsami.9b19776] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The high-resolution technique transmission electron microscopy (TEM), with OsO4 as the traditional fixative, is an essential tool for cell biology and medicine. Although OsO4 has been extensively used, it is far from perfect because of its high volatility and toxicity. Os(II) polypyridyl complexes like [Os(phen)2(dppz)]2+ (phen = 1,10-phenanthroline; dppz = dipyridophenazine) are not only the well-known molecular DNA "light-switches" but also the potential ideal candidates for TEM studies. Here, we report that the cell-impermeable cationic [Os(phen)2(dppz)]2+ can be preferentially delivered into the live-cell nucleus through ion-pairing with chlorophenolate counter-anions, where it functions as an unparalleled enantioselective nuclear DNA imaging reagent especially suitable for correlative light and electron microscopy (CLEM) studies in both living and fixed cells, which can clearly visualize chromosome aggregation and decondensation during mitosis simultaneously. We propose that the chiral Os(II) polypyridyl complexes can be used as a distinctive group of enantioselective high-resolution CLEM imaging probes for live-cell nuclear DNA studies.
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Affiliation(s)
- Rong Huang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , P. R. China
- University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
| | - Feng-Ping Feng
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics , Chinese Academy of Sciences , Beijing 100101 , China
| | - Chun-Hua Huang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , P. R. China
- University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
| | - Li Mao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , P. R. China
- University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
| | - Miao Tang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , P. R. China
- University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
| | - Zhu-Ying Yan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , P. R. China
- University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
| | - Bo Shao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , P. R. China
- University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
| | - Li Qin
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , P. R. China
- University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
| | - Tao Xu
- University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics , Chinese Academy of Sciences , Beijing 100101 , China
| | - Yan-Hong Xue
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics , Chinese Academy of Sciences , Beijing 100101 , China
| | - Ben-Zhan Zhu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences , Chinese Academy of Sciences , Beijing 100085 , P. R. China
- University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
- Joint Institute for Environmental Science , Research Center for Eco-Environmental Sciences and Hong Kong Baptist University , Kowloon 999077 , Hong Kong
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18
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O Connor D, Byrne A, Berselli GB, Long C, Keyes TE. Mega-stokes pyrene ceramide conjugates for STED imaging of lipid droplets in live cells. Analyst 2019; 144:1608-1621. [PMID: 30631867 DOI: 10.1039/c8an02260g] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Lipid droplets are dynamic subcellular organelles that participate in a range of physiological processes including metabolism, regulation and lipid storage. Their role in disease, such as cancer, where they are involved in metabolism and in chemoresistance, has emerged over recent years. Thus, the value of lipid droplets as diagnostic markers is increasingly apparent where number and size of droplets can be a useful prognostic. Although diverse in size, LDs are typically too small to be easily enumerated by conventional microscopy. The advent of super-resolution microscopy methods offers the prospect of detailed insights but there are currently no commercial STED probes suited to this task and STED, where this method has been used to study LDs it has relied on fixed samples. Here, we report a pyrene-based ceramide conjugate PyLa-C17Cer, that stains lipid droplets with exceptionally high precision in living cells and shows excellent performance in stimulated emission depletion microscopy. The parent compound PyLa comprises a pyrene carboxyl core appended with 3,4-dimethylaminophenyl. The resulting luminophore exhibits high fluorescent quantum yield, mega-Stokes shift and low cytotoxicity. From DFT calculations the Stokes shifted fluorescent state arises from a dimethylaminophenyl to pyrene charge-transfer transition. While the parent compound is cell permeable, it is relatively promiscuous, emitting from both protein and membranous structures within the living mammalian cell. However, on conjugation of C17 ceramide to the free carboxylic acid, the resulting PyLa-C17Cer, remains passively permeable to the cell membrane but targets lipid droplets within the cell through a temperature dependent mechanism, with high selectivity. Targeting was confirmed through colocalisation with the commercial lipid probe Nile Red. PyLa-C17Cer offers outstanding contrast of LDs both in fluorescence intensity and lifetime imaging due to its large Stokes shift and very weak emission from aqueous media. Moreover, because the compound is exceptionally photochemically stable with no detectable triplet emission under low temperature conditions, it can be used as an effective probe for fluorescence correlation spectroscopy (FCS). These versatile fluorophores are powerful multimodal probes for combined STED/FCS/lifetime studies of lipid droplets and domains in live cells.
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Affiliation(s)
- Darragh O Connor
- School of Chemical Sciences, National Centre for Sensor Research, Dublin City University, Dublin 9, Ireland.
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19
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Scattergood PA, Roberts J, Omar SAE, Elliott PIP. Observation of an Inversion in Photophysical Tuning in a Systematic Study of Luminescent Triazole-Based Osmium(II) Complexes. Inorg Chem 2019; 58:8607-8621. [PMID: 31180230 DOI: 10.1021/acs.inorgchem.9b00915] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In a systematic survey of luminescent bis(terdentate) osmium(II) complexes, a tipping point involving a reversal in photophysical tuning is observed whereby increasing stabilization of the ligand-based lowest unoccupied molecular orbital (LUMO) results in a blue shift in the optical absorption and emission bands. The complexes [Os(N^N'^N″)2]2+ [N^N'^N″ = 2,6-bis(1-phenyl-1,2,3-triazol-4-yl)pyridine (Os1), 2,6-bis(1-benzyl-1,2,3-triazol-4-yl)pyrazine (Os2), 6-(1-benzyl-1,2,3-triazol-4-yl)-2,2'-bipyridyl (Os3), 2-(pyrid-2-yl)-6-(1-benzyl-1,2,3-triazol-4-yl)pyrazine (Os4), 2-(pyrazin-2-yl)-6-(1-benzyl-1,2,3-triazol-4-yl)pyridine (Os5), and 6-(1-benzyl-1,2,3-triazol-4-yl)-2,2'-bipyrazinyl (Os6)] have been prepared and characterized, and all complexes display phosphorescence ranging from the orange to near-IR regions of the spectrum. Replacement of the central pyridine in the ligands of Os1 by the more π-accepting pyrazine in Os2 results in a 55 nm red shift in the triplet metal-to-ligand charge-transfer-based emission band, while a larger red shift of 107 nm is observed for the replacement of one of the triazole donors in the ligands of Os1 by a second pyridine ring in Os3 (λemmax = 702 nm). Interestingly, replacement of the central pyridine ring in the ligands of Os3 by pyrazine (Os4, λemmax = 702 nm) fails to result in a further red shift in the emission band. Reversal of the relative positions of the pyridine and pyrazine donors in Os5 (λemmax = 733 nm) compared to Os4 does indeed result in the expected red shift in the emission with respect to that for Os3 based on the increased π-acceptor character of the ligands present. However, an inversion in emission tuning is observed for Os6, in which the incorporation of a second pyrazine donor in the ligand architecture results in a blue shift in the optical absorption and emission maxima (λemmax = 710 nm). Electrochemical studies reveal that while incorporating pyrazine in the ligands indeed results in an expected anodic shift in the first reduction potential through stabilization of the ligand-based LUMO, there is also a concomitant anodic shift in the OsII/OsIII-based oxidation potential. This stabilization of the metal-based highest occupied molecular orbital (HOMO) thus nullifies the effect of stabilization of the LUMO in Os4 compared to Os3, resulting in these complexes having coincident emission maxima. For Os6, stabilization of the HOMO through the incorporation of two pyrazine donors in the ligand structure now exceeds stabilization of the LUMO, resulting in a larger HOMO-LUMO gap and a counterintuitive blue shift in the optical properties in comparison with those of Os5. While it is known that the replacement of ligands (e.g., replacing bipyridyl with bipyrazinyl) can result in a larger HOMO-LUMO energy gap through greater stabilization of the HOMO, these results importantly allow us to capture the tipping point at which this inversion in photophysical tuning occurs. This therefore enables us to explore the limits available in emission tuning with a relatively simple and minimalist ligand structure.
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20
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Omar SAE, Scattergood PA, McKenzie LK, Jones C, Patmore NJ, Meijer AJHM, Weinstein JA, Rice CR, Bryant HE, Elliott PIP. Photophysical and Cellular Imaging Studies of Brightly Luminescent Osmium(II) Pyridyltriazole Complexes. Inorg Chem 2018; 57:13201-13212. [PMID: 30351084 DOI: 10.1021/acs.inorgchem.8b01627] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The series of complexes [Os(bpy)3- n(pytz) n][PF6]2 (bpy = 2,2'-bipyridyl, pytz = 1-benzyl-4-(pyrid-2-yl)-1,2,3-triazole, 1 n = 0, 2 n = 1, 3 n = 2, 4 n = 3) were prepared and characterized and are rare examples of luminescent 1,2,3-triazole-based osmium(II) complexes. For 3 we present an attractive and particularly mild preparative route via an osmium(II) η6-arene precursor circumventing the harsh conditions that are usually required. Because of the high spin-orbit coupling constant associated with the Os(II) center the absorption spectra of the complexes all display absorption bands of appreciable intensity in the range of 500-700 nm corresponding to spin-forbidden ground-state-to-3MLCT transitions (MLCT = metal-to-ligand charge transfer), which occur at significantly lower energies than the corresponding spin-allowed 1MLCT transitions. The homoleptic complex 4 is a bright emitter (λmaxem = 614 nm) with a relatively high quantum yield of emission of ∼40% in deoxygenated acetonitrile solutions at room temperature. Water-soluble chloride salts of 1-4 were also prepared, all of which remain emissive in aerated aqueous solutions at room temperature. The complexes were investigated for their potential as phosphorescent cellular imaging agents, whereby efficient excitation into the 3MLCT absorption bands at the red side of the visible range circumvents autofluorescence from biological specimens, which do not absorb in this region of the spectrum. Confocal microscopy reveals 4 to be readily taken up by cancer cell lines (HeLa and EJ) with apparent lysosomal and endosomal localization, while toxicity assays reveal that the compounds have low dark and light toxicity. These complexes therefore provide an excellent platform for the development of efficient luminescent cellular imaging agents with advantageous photophysical properties that enable excitation and emission in the biologically transparent region of the optical spectrum.
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Affiliation(s)
| | | | - Luke K McKenzie
- Academic Unit of Molecular Oncology, Sheffield Institute for Nucleic Acids, Department of Oncology and Metabolism , University of Sheffield , Beech Hill Road , Sheffield S10 2RX , U.K
- Department of Chemistry , University of Sheffield , Brook Hill , Sheffield S3 7HF , U.K
| | - Callum Jones
- Academic Unit of Molecular Oncology, Sheffield Institute for Nucleic Acids, Department of Oncology and Metabolism , University of Sheffield , Beech Hill Road , Sheffield S10 2RX , U.K
| | | | - Anthony J H M Meijer
- Department of Chemistry , University of Sheffield , Brook Hill , Sheffield S3 7HF , U.K
| | - Julia A Weinstein
- Department of Chemistry , University of Sheffield , Brook Hill , Sheffield S3 7HF , U.K
| | | | - Helen E Bryant
- Academic Unit of Molecular Oncology, Sheffield Institute for Nucleic Acids, Department of Oncology and Metabolism , University of Sheffield , Beech Hill Road , Sheffield S10 2RX , U.K
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21
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Kajouj S, Marcelis L, Mattiuzzi A, Grassin A, Dufour D, Van Antwerpen P, Boturyn D, Defrancq E, Surin M, De Winter J, Gerbaux P, Jabin I, Moucheron C. Synthesis and photophysical studies of a multivalent photoreactive Ru II-calix[4]arene complex bearing RGD-containing cyclopentapeptides. Beilstein J Org Chem 2018; 14:1758-1768. [PMID: 30112081 PMCID: PMC6071717 DOI: 10.3762/bjoc.14.150] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Accepted: 06/21/2018] [Indexed: 01/09/2023] Open
Abstract
Photoactive ruthenium-based complexes are actively studied for their biological applications as potential theragnostic agents against cancer. One major issue of these inorganic complexes is to penetrate inside cells in order to fulfil their function, either sensing the internal cell environment or exert a photocytotoxic activity. The use of lipophilic ligands allows the corresponding ruthenium complexes to passively diffuse inside cells but limits their structural and photophysical properties. Moreover, this strategy does not provide any cell selectivity. This limitation is also faced by complexes anchored on cell-penetrating peptides. In order to provide a selective cell targeting, we developed a multivalent system composed of a photoreactive ruthenium(II) complex tethered to a calix[4]arene platform bearing multiple RGD-containing cyclopentapeptides. Extensive photophysical and photochemical characterizations of this Ru(II)–calixarene conjugate as well as the study of its photoreactivity in the presence of guanosine monophosphate have been achieved. The results show that the ruthenium complex should be able to perform efficiently its photoinduced cytotoxic activity, once incorporated into targeted cancer cells thanks to the multivalent platform.
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Affiliation(s)
- Sofia Kajouj
- Laboratoire de Chimie Organique et Photochimie, Université libre de Bruxelles, Avenue F.D. Roosevelt 50, CP 160/08, 1050 Bruxelles, Belgium
| | - Lionel Marcelis
- Laboratoire de Chimie Organique et Photochimie, Université libre de Bruxelles, Avenue F.D. Roosevelt 50, CP 160/08, 1050 Bruxelles, Belgium.,Engineering of Molecular NanoSystems, Ecole Polytechnique de Bruxelles, Université libre de Bruxelles (ULB), Avenue F.D. Roosevelt 50, CP165/64, B-1050 Brussels, Belgium
| | - Alice Mattiuzzi
- Laboratoire de Chimie Organique, Université libre de Bruxelles, Avenue F.D. Roosevelt 50, CP 160/06, 1050 Bruxelles, Belgium
| | - Adrien Grassin
- Université Grenoble Alpes, Département de Chimie Moléculaire UMR CNRS 5250, CS 40700, 38058 Grenoble Cedex 09, France
| | - Damien Dufour
- Analytical Platform of the Faculty of Pharmacy, Université libre de Bruxelles, Boulevard du Triomphe, Campus de la Plaine, CP205/05, 1050 Bruxelles, Belgium
| | - Pierre Van Antwerpen
- Analytical Platform of the Faculty of Pharmacy, Université libre de Bruxelles, Boulevard du Triomphe, Campus de la Plaine, CP205/05, 1050 Bruxelles, Belgium
| | - Didier Boturyn
- Université Grenoble Alpes, Département de Chimie Moléculaire UMR CNRS 5250, CS 40700, 38058 Grenoble Cedex 09, France
| | - Eric Defrancq
- Université Grenoble Alpes, Département de Chimie Moléculaire UMR CNRS 5250, CS 40700, 38058 Grenoble Cedex 09, France
| | - Mathieu Surin
- Laboratory for Chemistry of Novel Materials, Center for Innovation and Research in Materials and Polymers, University of Mons - UMONS, 20, Place du Parc, B-7000 Mons, Belgium
| | - Julien De Winter
- Organic synthesis and Mass Spectrometry Laboratory, University of Mons - UMONS, Place du Parc 23, B-7000 Mons, Belgium
| | - Pascal Gerbaux
- Organic synthesis and Mass Spectrometry Laboratory, University of Mons - UMONS, Place du Parc 23, B-7000 Mons, Belgium
| | - Ivan Jabin
- Laboratoire de Chimie Organique, Université libre de Bruxelles, Avenue F.D. Roosevelt 50, CP 160/06, 1050 Bruxelles, Belgium
| | - Cécile Moucheron
- Laboratoire de Chimie Organique et Photochimie, Université libre de Bruxelles, Avenue F.D. Roosevelt 50, CP 160/08, 1050 Bruxelles, Belgium
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22
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Fernández-Moreira V, Gimeno MC. Heterobimetallic Complexes for Theranostic Applications. Chemistry 2018; 24:3345-3353. [PMID: 29334153 DOI: 10.1002/chem.201705335] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Indexed: 01/31/2023]
Abstract
The design of more efficient anticancer drugs requires a deeper understanding of their biodistribution and mechanism of action. Cell imaging agents could help to gain insight into biological processes and, consequently, the best strategy for attaining suitable scaffolds in which both biological and imaging properties are maximized. A new concept arises in this field that is the combination of two metal fragments as collaborative partners to provide the precise emissive properties to visualize the cell as well as the optimum cytotoxic activity to build more potent and selective chemotherapeutic agents.
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Affiliation(s)
- Vanesa Fernández-Moreira
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, Calle de Pedro Cerbuna 12, 50009, Zaragoza, Spain
| | - M Concepción Gimeno
- Departamento de Química Inorgánica, Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC-Universidad de Zaragoza, Calle de Pedro Cerbuna 12, 50009, Zaragoza, Spain
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23
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Stumper A, Lämmle M, Mengele AK, Sorsche D, Rau S. One Scaffold, Many Possibilities - Copper(I)-Catalyzed Azide-Alkyne Cycloadditions, Strain-Promoted Azide-Alkyne Cycloadditions, and Maleimide-Thiol Coupling of Ruthenium(II) Polypyridyl Complexes. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201701126] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Anne Stumper
- Institute of Inorganic Chemistry, Materials and Catalysis; Ulm University; Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Martin Lämmle
- Institute of Inorganic Chemistry, Materials and Catalysis; Ulm University; Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Alexander K. Mengele
- Institute of Inorganic Chemistry, Materials and Catalysis; Ulm University; Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Dieter Sorsche
- Institute of Inorganic Chemistry, Materials and Catalysis; Ulm University; Albert-Einstein-Allee 11 89081 Ulm Germany
| | - Sven Rau
- Institute of Inorganic Chemistry, Materials and Catalysis; Ulm University; Albert-Einstein-Allee 11 89081 Ulm Germany
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24
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Konkankit CC, Marker SC, Knopf KM, Wilson JJ. Anticancer activity of complexes of the third row transition metals, rhenium, osmium, and iridium. Dalton Trans 2018; 47:9934-9974. [DOI: 10.1039/c8dt01858h] [Citation(s) in RCA: 153] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A summary of recent developments on the anticancer activity of complexes of rhenium, osmium, and iridium is described.
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Affiliation(s)
| | - Sierra C. Marker
- Department of Chemistry and Chemical Biology
- Cornell University
- Ithaca
- USA
| | - Kevin M. Knopf
- Department of Chemistry and Chemical Biology
- Cornell University
- Ithaca
- USA
| | - Justin J. Wilson
- Department of Chemistry and Chemical Biology
- Cornell University
- Ithaca
- USA
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25
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Zhang P, Huang H. Future potential of osmium complexes as anticancer drug candidates, photosensitizers and organelle-targeted probes. Dalton Trans 2018; 47:14841-14854. [DOI: 10.1039/c8dt03432j] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Here we summarize recent progress in the design and application of innovative osmium compounds as anticancer agents with diverse modes of action, as organelle-targeted imaging probes and photosensitizers for photodynamic therapy.
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Affiliation(s)
- Pingyu Zhang
- College of Chemistry and Environmental Engineering
- Shenzhen University
- Shenzhen
- P. R. China
| | - Huaiyi Huang
- School of Pharmaceutical Sciences (Shenzhen)
- Sun Yat-sen University
- Guangzhou 510275
- P. R. China
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26
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Emerging landscape of cell penetrating peptide in reprogramming and gene editing. J Control Release 2016; 226:124-37. [DOI: 10.1016/j.jconrel.2016.02.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 01/31/2016] [Accepted: 02/01/2016] [Indexed: 12/11/2022]
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27
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Bist I, Song B, Mosa IM, Keyes TE, Martin A, Forster RJ, Rusling JF. Electrochemiluminescent Array to Detect Oxidative Damage in ds-DNA Using [Os(bpy) 2(phen-benz-COOH)] 2+/Nafion/Graphene Films. ACS Sens 2016; 1:272-278. [PMID: 27135053 DOI: 10.1021/acssensors.5b00189] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Reactive oxygen species (ROS) oxidize guanosines in DNA to form 8-oxo-7,8-dihydro-2-deoxyguanosine (8-oxodG), a biomarker for oxidative stress. Herein we describe a novel 64-microwell electrochemiluminescent (ECL) array enabling sensitive multiplexed detection of 8-oxodG in ds-DNA without hydrolysis. Films of Nafion and reduced graphene oxide containing ECL dye [Os(bpy)2(phen-benz-COOH)]2+ (OsNG, {bpy= 2,2'-bipyridine and phen-benz-COOH = (4-(1,10-phenanthrolin-6-yl) benzoic acid)}) were assembled into microwells on a pyrolytic graphite wafer to detect 8-oxodG in oligonucleotides by electrochemiluminescence (ECL). DNA oxidation by Fenton's reagent or by ROS formation during redox cycles involving NADPH, CuII, and model metabolites was monitored. UPLC-MS/MS of oxidized DNA samples were used for calibration. Detection limit for the fluidic arrays was one 8-oxodG per 670 intact nucleobases, or 0.15%. The method is sensitive enough to evaluate DNA oxidation from biologically relevant ROS-generating reactions of CuII, NADPH, and model metabolites.
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Affiliation(s)
| | | | - Islam M. Mosa
- Department
of Chemistry, Tanta University, Tanta 31527, Egypt
| | - Tia E. Keyes
- School
of Chemical Sciences, Dublin City University, Dublin 9, Ireland
| | - Aaron Martin
- School
of Chemical Sciences, Dublin City University, Dublin 9, Ireland
| | - Robert J. Forster
- School
of Chemical Sciences, Dublin City University, Dublin 9, Ireland
| | - James F. Rusling
- School
of Chemistry, National University of Ireland, Galway, Ireland
- University of Connecticut Health Center, Farmington, Connecticut 06032, United States
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28
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Burke CS, Keyes TE. An efficient route to asymmetrically diconjugated tris(heteroleptic) complexes of Ru(ii). RSC Adv 2016. [DOI: 10.1039/c6ra06086b] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A highly efficient and versatile route to the preparation of tris(heteroleptic) Ru(ii) polypyridyl complexes is described which permits access to two or more independently conjugatable termini in the final structure.
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Affiliation(s)
- Christopher S. Burke
- School of Chemical Sciences
- National Centre for Sensor Research
- Dublin City University
- Dublin 9
- Ireland
| | - Tia E. Keyes
- School of Chemical Sciences
- National Centre for Sensor Research
- Dublin City University
- Dublin 9
- Ireland
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29
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Laramée-Milette B, Hanan GS. Ruthenium bistridentate complexes with non-symmetrical hexahydro-pyrimidopyrimidine ligands: a structural and theoretical investigation of their optical and electrochemical properties. Dalton Trans 2016; 45:12507-17. [DOI: 10.1039/c6dt02408d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The optical and electronic properties of six Ru complexes with non-symmetrical tridentate ligands have been investigated and, as corroborated by electrochemical data, the presence of the hpp ligand strongly affects the oxidation potential of the metal ion.
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Affiliation(s)
| | - Garry S. Hanan
- Département de Chimie
- Université de Montréal
- Montréal
- Canada
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