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Haitjema J, Castellanos S, Lugier O, Bespalov I, Lindblad R, Timm M, Bülow C, Zamudio-Bayer V, Lau JT, von Issendorff B, Hoekstra R, Witte K, Watts B, Schlathölter T, Brouwer AM. Soft X-ray absorption and fragmentation of tin-oxo cage photoresists. Phys Chem Chem Phys 2024; 26:5986-5998. [PMID: 38293812 DOI: 10.1039/d3cp05428d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
"Tin-oxo cage" organometallic compounds are considered as photoresists for extreme ultraviolet (EUV) photolithography. To gain insight into their electronic structure and reactivity to ionizing radiation, we trapped bare gas-phase n-butyltin-oxo cage dications [(BuSn)12O14(OH)6]2+ in an ion trap and investigated their fragmentation upon soft X-ray photoabsorption by means of mass spectrometry. In complementary experiments, the tin-oxo cages with hydroxide and trifluoroacetate counter-anions were cast in thin films and studied using X-ray transmission spectroscopy. Quantum-chemical calculations were used to interpret the observed spectra. At the carbon K-edge, a distinct pre-edge absorption band can be attributed to transitions in which electrons are promoted from C1s orbitals to the lowest unoccupied molecular orbitals, which are delocalized orbitals with strong antibonding (Sn-C σ*) character. At higher energies, the most prominent resonant transitions involve C-C and C-H σ* valence states and Rydberg (3s and 3p) states. In the solid state, the onset of continuum ionization is shifted by ∼5 eV to lower energy with respect to the gas phase, due to the electrostatic effect of the counterions. The O K-edge also shows a pre-edge absorption, but it is devoid of any specific features, because there are many transitions from the different O1s orbitals to a large number of vacant orbitals. In the gas phase, formation of the parent [(BuSn)12O14(OH)6]3+ radical ion is not observed at the C K-edge nor at the O K-edge, because the loss of a butyl group from this species is very efficient. We do observe a number of triply charged photofragment ions, some of which have lost up to 5 butyl groups. Structures of these species are proposed based on quantum-chemical calculations, and pathways of formation are discussed. Our results provide insight into the electronic structure of alkyltin-oxo cages, which is a prerequisite for understanding their response to EUV photons and their performance as EUV photoresists.
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Affiliation(s)
- Jarich Haitjema
- Advanced Research Center for Nanolithography, P.O. Box 93019, 1090 BA Amsterdam, The Netherlands.
| | - Sonia Castellanos
- Advanced Research Center for Nanolithography, P.O. Box 93019, 1090 BA Amsterdam, The Netherlands.
| | - Olivier Lugier
- Advanced Research Center for Nanolithography, P.O. Box 93019, 1090 BA Amsterdam, The Netherlands.
| | - Ivan Bespalov
- Advanced Research Center for Nanolithography, P.O. Box 93019, 1090 BA Amsterdam, The Netherlands.
| | - Rebecka Lindblad
- Department of Physics, Lund University, 22100 Lund, Sweden
- Abteilung für Hochempfindliche Röntgenspektroskopie, Helmholtz Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489 Berlin, Germany
| | - Martin Timm
- Abteilung für Hochempfindliche Röntgenspektroskopie, Helmholtz Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489 Berlin, Germany
| | - Christine Bülow
- Abteilung für Hochempfindliche Röntgenspektroskopie, Helmholtz Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489 Berlin, Germany
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104 Freiburg, Germany
| | - Vicente Zamudio-Bayer
- Abteilung für Hochempfindliche Röntgenspektroskopie, Helmholtz Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489 Berlin, Germany
| | - J Tobias Lau
- Abteilung für Hochempfindliche Röntgenspektroskopie, Helmholtz Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489 Berlin, Germany
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104 Freiburg, Germany
| | - Bernd von Issendorff
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Straße 3, 79104 Freiburg, Germany
| | - Ronnie Hoekstra
- Advanced Research Center for Nanolithography, P.O. Box 93019, 1090 BA Amsterdam, The Netherlands.
- Zernike Institute for Advanced Materials, Rijksuniversiteit Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
| | | | | | - Thomas Schlathölter
- Zernike Institute for Advanced Materials, Rijksuniversiteit Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
- University College Groningen, University of Groningen, Hoendiepskade 23/24, 9718 BG Groningen, The Netherlands
| | - Albert M Brouwer
- Advanced Research Center for Nanolithography, P.O. Box 93019, 1090 BA Amsterdam, The Netherlands.
- University of Amsterdam, van't Hoff Institute for Molecular Sciences, P.O. Box 94157, 1090 GD Amsterdam, The Netherlands
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Dieleman CD, Ding W, Wu L, Thakur N, Bespalov I, Daiber B, Ekinci Y, Castellanos S, Ehrler B. Universal direct patterning of colloidal quantum dots by (extreme) ultraviolet and electron beam lithography. Nanoscale 2020; 12:11306-11316. [PMID: 32421115 DOI: 10.1039/d0nr01077d] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Colloidal quantum dots have found many applications and patterning them on micro- and nanoscale would open a new dimension of tunability for the creation of smaller scale (flexible) electronics or nanophotonic structures. Here we present a simple, general, one-step top-down patterning technique for colloidal quantum dots by means of direct optical or electron beam lithography. We find that both photons and electrons can induce a solubility switch of both PbS and CdSe quantum dot films. The solubility switch can be ascribed to cross-linking of the organic ligands, which we observe from exposure with deep-UV photons (5.5 eV) to extreme-UV photons (91.9 eV), and low-energy (3-70 eV) as well as highly energetic electrons (50 keV). The required doses for patterning are relatively low and feature sizes can be as small as tens of nanometers. The luminescence properties as well as carrier lifetimes remain similar after patterning.
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Affiliation(s)
- Christian D Dieleman
- AMOLF, Center for Nanophotonics, Science Park 104, 1098XG Amsterdam, The Netherlands.
| | - Weiyi Ding
- AMOLF, Center for Nanophotonics, Science Park 104, 1098XG Amsterdam, The Netherlands.
| | - Lianjia Wu
- Advanced Research Center for Nanolithography, EUV Photoresists Group, Science Park 106, 1098 XG Amsterdam, The Netherlands.
| | - Neha Thakur
- Advanced Research Center for Nanolithography, EUV Photoresists Group, Science Park 106, 1098 XG Amsterdam, The Netherlands.
| | - Ivan Bespalov
- Advanced Research Center for Nanolithography, EUV Photoresists Group, Science Park 106, 1098 XG Amsterdam, The Netherlands.
| | - Benjamin Daiber
- AMOLF, Center for Nanophotonics, Science Park 104, 1098XG Amsterdam, The Netherlands.
| | - Yasin Ekinci
- Paul Scherrer Institute, Laboratory of Micro and Nanotechnology, Forschungsstrasse 111, 5232 Villigen, Switzerland
| | - Sonia Castellanos
- Advanced Research Center for Nanolithography, EUV Photoresists Group, Science Park 106, 1098 XG Amsterdam, The Netherlands.
| | - Bruno Ehrler
- AMOLF, Center for Nanophotonics, Science Park 104, 1098XG Amsterdam, The Netherlands.
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Bespalov I, Zhang Y, Haitjema J, Tromp RM, van der Molen SJ, Brouwer AM, Jobst J, Castellanos S. Key Role of Very Low Energy Electrons in Tin-Based Molecular Resists for Extreme Ultraviolet Nanolithography. ACS Appl Mater Interfaces 2020; 12:9881-9889. [PMID: 32019303 DOI: 10.1021/acsami.9b19004] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Extreme ultraviolet (EUV) lithography (13.5 nm) is the newest technology that allows high-throughput fabrication of electronic circuitry in the sub-20 nm scale. It is commonly assumed that low-energy electrons (LEEs) generated in the resist materials by EUV photons are mostly responsible for the solubility switch that leads to nanopattern formation. Yet, reliable quantitative information on this electron-induced process is scarce. In this work, we combine LEE microscopy (LEEM), electron energy loss spectroscopy (EELS), and atomic force microscopy (AFM) to study changes induced by electrons in the 0-40 eV range in thin films of a state-of-the-art molecular organometallic EUV resist known as tin-oxo cage. LEEM-EELS uniquely allows to correct for surface charging and thus to accurately determine the electron landing energy. AFM postexposure analyses revealed that irradiation of the resist with LEEs leads to the densification of the resist layer because of carbon loss. Remarkably, electrons with energies as low as 1.2 eV can induce chemical reactions in the Sn-based resist. Electrons with higher energies are expected to cause electronic excitation or ionization, opening up more pathways to enhanced conversion. However, we do not observe a substantial increase of chemical conversion (densification) with the electron energy increase in the 2-40 eV range. Based on the dose-dependent thickness profiles, a simplified reaction model is proposed where the resist undergoes sequential chemical reactions, first yielding a sparsely cross-linked network and then a more densely cross-linked network. This model allows us to estimate a maximum reaction volume on the initial material of 0.15 nm3 per incident electron in the energy range studied, which means that about 10 LEEs per molecule on average are needed to turn the material insoluble and thus render a pattern. Our observations are consistent with the observed EUV sensitivity of tin-oxo cages.
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Affiliation(s)
- Ivan Bespalov
- Advanced Research Center for Nanolithography , Science Park 104 , 1098XG Amsterdam , The Netherlands
| | - Yu Zhang
- Advanced Research Center for Nanolithography , Science Park 104 , 1098XG Amsterdam , The Netherlands
| | - Jarich Haitjema
- Advanced Research Center for Nanolithography , Science Park 104 , 1098XG Amsterdam , The Netherlands
| | - Rudolf M Tromp
- Kamerlingh Onnes Laboratory , Leiden University , Niels Bohrweg 2 , 2333 CA Leiden , The Netherlands
- IBM T. J. Watson Research Center , 1101 Kitchawan Road , P.O. Box 218, Yorktown Heights , 10598 New York , United States
| | - Sense Jan van der Molen
- Kamerlingh Onnes Laboratory , Leiden University , Niels Bohrweg 2 , 2333 CA Leiden , The Netherlands
| | - Albert M Brouwer
- Advanced Research Center for Nanolithography , Science Park 104 , 1098XG Amsterdam , The Netherlands
- van't Hoff Institute for Molecular Sciences , University of Amsterdam , P.O. Box 94157, 1090 GD Amsterdam , The Netherlands
| | - Johannes Jobst
- Kamerlingh Onnes Laboratory , Leiden University , Niels Bohrweg 2 , 2333 CA Leiden , The Netherlands
| | - Sonia Castellanos
- Advanced Research Center for Nanolithography , Science Park 104 , 1098XG Amsterdam , The Netherlands
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Suchorski Y, Bespalov I, Zeininger J, Raab M, Datler M, Winkler P, Rupprechter G. CO Oxidation on Stepped Rh Surfaces: μm-Scale Versus Nanoscale. Catal Letters 2019. [DOI: 10.1007/s10562-019-02950-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
The catalytic CO oxidation reaction on stepped Rh surfaces in the 10−6 mbar pressure range was studied in situ on individual μm-sized high-Miller-index domains of a polycrystalline Rh foil and on nm-sized facets of a Rh tip, employing photoemission electron microscopy (PEEM) and field-ion/field-emission microscopy (FIM/FEM), respectively. Such approach permits a direct comparison of the reaction kinetics for crystallographically different regions under identical reaction conditions. The catalytic activity of the different Rh surfaces, particularly their tolerance towards poisoning by CO, was found to be strongly dependent on the density of steps and defects, as well as on the size (µm vs. nm) of the respective catalytically active surface.
Graphic Abstract
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Suchorski Y, Datler M, Bespalov I, Zeininger J, Stöger-Pollach M, Bernardi J, Grönbeck H, Rupprechter G. Surface-Structure Libraries: Multifrequential Oscillations in Catalytic Hydrogen Oxidation on Rhodium. J Phys Chem C Nanomater Interfaces 2019; 123:4217-4227. [PMID: 31057690 PMCID: PMC6494118 DOI: 10.1021/acs.jpcc.8b11421] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 01/18/2019] [Indexed: 05/18/2023]
Abstract
Multifrequential oscillating spatiotemporal patterns in the catalytic hydrogen oxidation on rhodium have been observed in situ in the 10-6 mbar pressure range using photoemission electron microscopy. The effect is manifested by periodic chemical waves, which travel over the polycrystalline Rh surface and change their oscillation frequency while crossing boundaries between different Rh(hkl) domains. Each crystallographically specific μm-sized Rh(hkl) domain exhibits an individual wave pattern and oscillation frequency, despite the global diffusional coupling of the surface reaction, altogether creating a structure library. This unique reaction behavior is attributed to the ability of stepped surfaces of high-Miller-index domains to facilitate the formation of subsurface oxygen, serving as a feedback mechanism of kinetic oscillations. Formation of a network of subsurface oxygen as a result of colliding reaction fronts was observed in situ. Microkinetic model analysis was used to rationalize the observed effects and to reveal the relation between the barriers for surface oxidation and oscillation frequency. Structural limits of the oscillations, the existence range of oscillations, as well as the effect of varying hydrogen pressure are demonstrated.
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Affiliation(s)
- Yuri Suchorski
- Institute
of Materials Chemistry, Technische Universität
Wien, Getreidemarkt 9, 1060 Vienna, Austria
| | - Martin Datler
- Institute
of Materials Chemistry, Technische Universität
Wien, Getreidemarkt 9, 1060 Vienna, Austria
| | - Ivan Bespalov
- Institute
of Materials Chemistry, Technische Universität
Wien, Getreidemarkt 9, 1060 Vienna, Austria
| | - Johannes Zeininger
- Institute
of Materials Chemistry, Technische Universität
Wien, Getreidemarkt 9, 1060 Vienna, Austria
| | | | - Johannes Bernardi
- USTEM, Technische Universität Wien, Wiedner Hauptstrasse 8-10, 1040 Vienna, Austria
| | - Henrik Grönbeck
- Department
of Physics and Competence Centre for Catalysis, Chalmers University of Technology, 41296 Gothenburg, Sweden
| | - Günther Rupprechter
- Institute
of Materials Chemistry, Technische Universität
Wien, Getreidemarkt 9, 1060 Vienna, Austria
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Suchorski Y, Kozlov SM, Bespalov I, Datler M, Vogel D, Budinska Z, Neyman KM, Rupprechter G. The role of metal/oxide interfaces for long-range metal particle activation during CO oxidation. Nat Mater 2018; 17:519-522. [PMID: 29760509 DOI: 10.1038/s41563-018-0080-y] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 04/12/2018] [Indexed: 05/25/2023]
Affiliation(s)
- Yuri Suchorski
- Institut für Materialchemie, Technische Universität Wien, Vienna, Austria
| | - Sergey M Kozlov
- Departament de Ciència dels Materials i Química Física and Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, Barcelona, Spain
| | - Ivan Bespalov
- Institut für Materialchemie, Technische Universität Wien, Vienna, Austria
| | - Martin Datler
- Institut für Materialchemie, Technische Universität Wien, Vienna, Austria
| | - Diana Vogel
- Institut für Materialchemie, Technische Universität Wien, Vienna, Austria
| | - Zuzana Budinska
- Institut für Materialchemie, Technische Universität Wien, Vienna, Austria
| | - Konstantin M Neyman
- Departament de Ciència dels Materials i Química Física and Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona, Barcelona, Spain.
- ICREA (Institució Catalana de Recerca i Estudis Avançats), Barcelona, Spain.
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7
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Suchorski Y, Datler M, Bespalov I, Zeininger J, Stöger-Pollach M, Bernardi J, Grönbeck H, Rupprechter G. Visualizing catalyst heterogeneity by a multifrequential oscillating reaction. Nat Commun 2018; 9:600. [PMID: 29426883 PMCID: PMC5807506 DOI: 10.1038/s41467-018-03007-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 01/12/2018] [Indexed: 11/23/2022] Open
Abstract
It is well documented that different surface structures of catalytically active metals may exhibit different catalytic properties. This is typically examined by comparing the catalytic activities and/or selectivities of various well-defined smooth and stepped/kinked single crystal surfaces. Here we report the direct observation of the heterogeneity of active polycrystalline surfaces under reaction conditions, which is manifested by multifrequential oscillations during hydrogen oxidation over rhodium, imaged in situ by photoemission electron microscopy. Each specific surface structure, i.e. the crystallographically different µm-sized domains of rhodium, exhibits an individual spiral pattern and oscillation frequency, despite the global diffusional coupling of the surface reaction. This reaction behavior is attributed to the ability of stepped surfaces of high-Miller-index domains to facilitate the formation of subsurface oxygen, serving as feedback mechanism of the observed oscillations. The current experimental findings, backed by microkinetic modeling, may open an alternative approach towards addressing the structure-sensitivity of heterogeneous surfaces.
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Affiliation(s)
- Yuri Suchorski
- Institute of Materials Chemistry, Technische Universität Wien, 1060, Vienna, Austria
| | - Martin Datler
- Institute of Materials Chemistry, Technische Universität Wien, 1060, Vienna, Austria
| | - Ivan Bespalov
- Institute of Materials Chemistry, Technische Universität Wien, 1060, Vienna, Austria
| | - Johannes Zeininger
- Institute of Materials Chemistry, Technische Universität Wien, 1060, Vienna, Austria
| | | | | | - Henrik Grönbeck
- Department of Physics and Competence Centre for Catalysis, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden
| | - Günther Rupprechter
- Institute of Materials Chemistry, Technische Universität Wien, 1060, Vienna, Austria.
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Mett V, Komarova EA, Greene K, Bespalov I, Brackett C, Gillard B, Gleiberman AS, Toshkov IA, Aygün-Sunar S, Johnson C, Karasik E, Bapardekar-Nair M, Kurnasov OV, Osterman AL, Stanhope-Baker PS, Morrison C, Moser MT, Foster BA, Gudkov AV. Mobilan: a recombinant adenovirus carrying Toll-like receptor 5 self-activating cassette for cancer immunotherapy. Oncogene 2017; 37:439-449. [PMID: 28967901 PMCID: PMC5799711 DOI: 10.1038/onc.2017.346] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 07/23/2017] [Accepted: 08/07/2017] [Indexed: 12/14/2022]
Abstract
Toll-like receptor 5 (TLR5) is considered an attractive target for anticancer immunotherapy. TLR5 agonists, bacterial flagellin and engineered flagellin derivatives, have been shown to have potent antitumor and metastasis-suppressive effects in multiple animal models and to be safe in both animals and humans. Anticancer efficacy of TLR5 agonists stems from TLR5-dependent activation of nuclear factor-κB (NF-κB) that mediates innate and adaptive antitumor immune responses. To extend application of TLR5-targeted anticancer immunotherapy to tumors that do not naturally express TLR5, we created an adenovirus-based vector for intratumor delivery, named Mobilan that drives expression of self-activating TLR5 signaling cassette comprising of human TLR5 and a secreted derivative of Salmonella flagellin structurally analogous to a clinical stage TLR5 agonist, entolimod. Co-expression of TLR5 receptor and agonist in Mobilan-infected cells established an autocrine/paracrine TLR5 signaling loop resulting in constitutive activation of NF-κB both in vitro and in vivo. Injection of Mobilan into primary tumors of the prostate cancer-prone transgenic adenocarcinoma of the mouse prostate (TRAMP) mice resulted in a strong induction of multiple genes involved in inflammatory responses and mobilization of innate immune cells into the tumors including neutrophils and NK cells and suppressed tumor progression. Intratumoral injection of Mobilan into subcutaneously growing syngeneic prostate tumors in immunocompetent hosts improved animal survival after surgical resection of the tumors, by suppression of tumor metastasis. In addition, vaccination of mice with irradiated Mobilan-transduced prostate tumor cells protected mice against subsequent tumor challenge. These results provide proof-of-concept for Mobilan as a tool for antitumor vaccination that directs TLR5-mediated immune response toward cancer cells and does not require identification of tumor antigens.
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Affiliation(s)
- V Mett
- Cleveland Biolabs Inc., Buffalo, NY, USA
| | - E A Komarova
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Buffalo, NY, USA
| | - K Greene
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Buffalo, NY, USA
| | - I Bespalov
- Cleveland Biolabs Inc., Buffalo, NY, USA
| | - C Brackett
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Buffalo, NY, USA
| | - B Gillard
- Department of Molecular Pharmacology and Cancer Therapeutics, Roswell Park Cancer Institute, Buffalo, NY, USA
| | | | | | | | - C Johnson
- Department of Cell Stress Biology, Roswell Park Cancer Institute, Buffalo, NY, USA
| | - E Karasik
- Department of Molecular Pharmacology and Cancer Therapeutics, Roswell Park Cancer Institute, Buffalo, NY, USA
| | | | - O V Kurnasov
- Infectious and Inflammatory Disease Center, Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - A L Osterman
- Infectious and Inflammatory Disease Center, Sanford-Burnham-Prebys Medical Discovery Institute, La Jolla, CA, USA
| | | | - C Morrison
- Department of Pathology, Roswell Park Cancer Institute, Buffalo, NY, USA
| | - M T Moser
- Department of Molecular Pharmacology and Cancer Therapeutics, Roswell Park Cancer Institute, Buffalo, NY, USA
| | - B A Foster
- Department of Molecular Pharmacology and Cancer Therapeutics, Roswell Park Cancer Institute, Buffalo, NY, USA
| | - A V Gudkov
- Cleveland Biolabs Inc., Buffalo, NY, USA.,Department of Cell Stress Biology, Roswell Park Cancer Institute, Buffalo, NY, USA
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Datler M, Bespalov I, Buhr S, Zeininger J, Stöger-Pollach M, Bernardi J, Rupprechter G, Suchorski Y. Hydrogen Oxidation on Stepped Rh Surfaces: µm-Scale versus Nanoscale. Catal Letters 2016; 146:1867-1874. [PMID: 32355436 PMCID: PMC7175702 DOI: 10.1007/s10562-016-1824-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 07/21/2016] [Indexed: 11/11/2022]
Abstract
Abstract The catalytic H2 oxidation reaction on stepped Rh surfaces in the 10−6 mbar pressure range was studied in situ on individual high-Miller-index domains of a polycrystalline Rh foil by PEEM (photoemission electron microscopy) and on a Rh nanotip by FIM/FEM (field-ion/field-emission microscopy). The activity, particularly the tolerance to poisoning by oxygen, was found to strongly depend on the density of steps and defects, as well as on the size of the catalytically active surfaces. Graphical Abstract ![]()
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Affiliation(s)
- M Datler
- 1Institute of Materials Chemistry, Technische Universität Wien, 1060 Vienna, Austria
| | - I Bespalov
- 1Institute of Materials Chemistry, Technische Universität Wien, 1060 Vienna, Austria
| | - S Buhr
- 1Institute of Materials Chemistry, Technische Universität Wien, 1060 Vienna, Austria
| | - J Zeininger
- 1Institute of Materials Chemistry, Technische Universität Wien, 1060 Vienna, Austria
| | - M Stöger-Pollach
- 2University Service Center for Transmission Electron Microscopy, Technische Universität Wien, 1060 Vienna, Austria
| | - J Bernardi
- 2University Service Center for Transmission Electron Microscopy, Technische Universität Wien, 1060 Vienna, Austria
| | - G Rupprechter
- 1Institute of Materials Chemistry, Technische Universität Wien, 1060 Vienna, Austria
| | - Y Suchorski
- 1Institute of Materials Chemistry, Technische Universität Wien, 1060 Vienna, Austria
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10
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Bespalov I, Datler M, Buhr S, Drachsel W, Rupprechter G, Suchorski Y. Initial stages of oxide formation on the Zr surface at low oxygen pressure: An in situ FIM and XPS study. Ultramicroscopy 2015; 159 Pt 2:147-51. [PMID: 25766998 PMCID: PMC4691236 DOI: 10.1016/j.ultramic.2015.02.016] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 12/10/2014] [Accepted: 02/26/2015] [Indexed: 11/29/2022]
Abstract
An improved methodology of the Zr specimen preparation was developed which allows fabrication of stable Zr nanotips suitable for FIM and AP applications. Initial oxidation of the Zr surface was studied on a Zr nanotip by FIM and on a polycrystalline Zr foil by XPS, both at low oxygen pressure (10(-8)-10(-7)mbar). The XPS data reveal that in a first, fast stage of oxidation, a Zr suboxide interlayer is formed which contains three suboxide components (Zr(+1), Zr(+2) and Zr(+3)) and is located between the Zr surface and a stoichiometric ZrO2 overlayer that grows in a second, slow oxidation stage. The sole suboxide layer has been observed for the first time at very early states of the oxidation (oxygen exposure ≤ 4L). The Ne(+) FIM observations are in accord with a two stage process of Zr oxide formation.
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Affiliation(s)
- I Bespalov
- Institute of Materials Chemistry, Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - M Datler
- Institute of Materials Chemistry, Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - S Buhr
- Institute of Materials Chemistry, Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - W Drachsel
- Institute of Materials Chemistry, Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - G Rupprechter
- Institute of Materials Chemistry, Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - Y Suchorski
- Institute of Materials Chemistry, Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria.
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Krivokrysenko VI, Toshkov IA, Gleiberman AS, Krasnov P, Shyshynova I, Bespalov I, Maitra RK, Narizhneva NV, Singh VK, Whitnall MH, Purmal AA, Shakhov AN, Gudkov AV, Feinstein E. The Toll-Like Receptor 5 Agonist Entolimod Mitigates Lethal Acute Radiation Syndrome in Non-Human Primates. PLoS One 2015; 10:e0135388. [PMID: 26367124 PMCID: PMC4569586 DOI: 10.1371/journal.pone.0135388] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 07/15/2015] [Indexed: 12/28/2022] Open
Abstract
There are currently no approved medical radiation countermeasures (MRC) to reduce the lethality of high-dose total body ionizing irradiation expected in nuclear emergencies. An ideal MRC would be effective even when administered well after radiation exposure and would counteract the effects of irradiation on the hematopoietic system and gastrointestinal tract that contribute to its lethality. Entolimod is a Toll-like receptor 5 agonist with demonstrated radioprotective/mitigative activity in rodents and radioprotective activity in non-human primates. Here, we report data from several exploratory studies conducted in lethally irradiated non-human primates (rhesus macaques) treated with a single intramuscular injection of entolimod (in the absence of intensive individualized supportive care) administered in a mitigative regimen, 1-48 hours after irradiation. Following exposure to LD50-70/40 of radiation, injection of efficacious doses of entolimod administered as late as 25 hours thereafter reduced the risk of mortality 2-3-fold, providing a statistically significant (P<0.01) absolute survival advantage of 40-60% compared to vehicle treatment. Similar magnitude of survival improvement was also achieved with drug delivered 48 hours after irradiation. Improved survival was accompanied by predominantly significant (P<0.05) effects of entolimod administration on accelerated morphological recovery of hematopoietic and immune system organs, decreased severity and duration of thrombocytopenia, anemia and neutropenia, and increased clonogenic potential of the bone marrow compared to control irradiated animals. Entolimod treatment also led to reduced apoptosis and accelerated crypt regeneration in the gastrointestinal tract. Together, these data indicate that entolimod is a highly promising potential life-saving treatment for victims of radiation disasters.
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Affiliation(s)
| | - Ilia A. Toshkov
- Cleveland BioLabs, Inc. (CBLI), Buffalo, New York, United States of America
| | | | - Peter Krasnov
- Cleveland BioLabs, Inc. (CBLI), Buffalo, New York, United States of America
| | - Inna Shyshynova
- Cleveland BioLabs, Inc. (CBLI), Buffalo, New York, United States of America
| | - Ivan Bespalov
- Cleveland BioLabs, Inc. (CBLI), Buffalo, New York, United States of America
| | - Ratan K. Maitra
- Cleveland BioLabs, Inc. (CBLI), Buffalo, New York, United States of America
| | | | - Vijay K. Singh
- Armed Forces Radiobiology Research Institute (AFRRI), Bethesda, Maryland, United States of America
| | - Mark H. Whitnall
- Armed Forces Radiobiology Research Institute (AFRRI), Bethesda, Maryland, United States of America
| | - Andrei A. Purmal
- Cleveland BioLabs, Inc. (CBLI), Buffalo, New York, United States of America
| | | | - Andrei V. Gudkov
- Cleveland BioLabs, Inc. (CBLI), Buffalo, New York, United States of America
- Department of Cell Stress Biology, Roswell Park Cancer Institute (RPCI), Buffalo, New York, United States of America
- * E-mail: (AVG); (EF)
| | - Elena Feinstein
- Cleveland BioLabs, Inc. (CBLI), Buffalo, New York, United States of America
- * E-mail: (AVG); (EF)
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12
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Bakhribah H, Dy GK, Ma WW, Zhao Y, Opyrchal M, Purmal A, Gollnick S, Brady WE, Fetterly GJ, Ngamphaiboon N, Reungwetwattana T, Jacob SM, O'Hara C, Siedlecki F, Adjei A, Burdelya L, Bespalov I, Miller LL, Gudkov A, Adjei AA. A phase I study of the toll-like receptor 5 (TLR5) agonist, entolimod in patients (pts) with advanced cancers. J Clin Oncol 2015. [DOI: 10.1200/jco.2015.33.15_suppl.3063] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
| | | | - Wen Wee Ma
- Roswell Park Cancer Institute, Buffalo, NY
| | - Yujie Zhao
- Roswell Park Cancer Institute, Buffalo, NY
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13
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Datler M, Bespalov I, Rupprechter G, Suchorski Y. Analysing the Reaction Kinetics for Individual Catalytically Active Components: CO Oxidation on a Pd Powder Supported by Pt Foil. Catal Letters 2015. [DOI: 10.1007/s10562-015-1486-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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14
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Reynolds M, Stoddard L, Bespalov I, Zhitkovich A. Ascorbate acts as a highly potent inducer of chromate mutagenesis and clastogenesis: linkage to DNA breaks in G2 phase by mismatch repair. Nucleic Acids Res 2006; 35:465-76. [PMID: 17169990 PMCID: PMC1802609 DOI: 10.1093/nar/gkl1069] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Here we examined the role of cellular vitamin C in genotoxicity of carcinogenic chromium(VI) that requires reduction to induce DNA damage. In the presence of ascorbate (Asc), low 0.2–2 μM doses of Cr(VI) caused 10–15 times more chromosomal breakage in primary human bronchial epithelial cells or lung fibroblasts. DNA double-strand breaks (DSB) were preferentially generated in G2 phase as detected by colocalization of γH2AX and 53BP1 foci in cyclin B1-expressing cells. Asc dramatically increased the formation of centromere-negative micronuclei, demonstrating that induced DSB were inefficiently repaired. DSB in G2 cells were caused by aberrant mismatch repair of Cr damage in replicated DNA, as DNA polymerase inhibitor aphidicolin and silencing of MSH2 or MLH1 by shRNA suppressed induction of γH2AX and micronuclei. Cr(VI) was also up to 10 times more mutagenic in cells containing Asc. Increasing Asc concentrations generated progressively more mutations and DSB, revealing the genotoxic potential of otherwise nontoxic Cr(VI) doses. Asc amplified genotoxicity of Cr(VI) by altering the spectrum of DNA damage, as total Cr-DNA binding was unchanged and post-Cr loading of Asc exhibited no effects. Collectively, these studies demonstrated that Asc-dependent metabolism is the main source of genotoxic and mutagenic damage in Cr(VI)-exposed cells.
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Affiliation(s)
| | | | | | - Anatoly Zhitkovich
- To whom correspondence should be addressed. Tel: +1 401 863 2912; Fax: +1 401 863 9008;
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15
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Persinger RL, Melamede R, Bespalov I, Wallace S, Taatjes DJ, Janssen-Heininger Y. Imaging techniques used for the detection of 8-oxoguanine adducts and DNA repair proteins in cells and tissues. Exp Gerontol 2001; 36:1483-94. [PMID: 11525871 DOI: 10.1016/s0531-5565(01)00134-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The presence of 8-oxoguanine (8-oxoG) in DNA is considered a marker of oxidative stress and DNA damage. Numerous biochemical techniques have been described for its detection in cells or tissues. Although these approaches are quantitative, they do not provide insights into whether the lesion occurs in mitochrondrial versus genomic DNA. In addition, biochemical techniques are not amenable to the evaluation of individual cells or archival tissues. Antibodies have been raised against 8-oxoG, which may circumvent some of these issues. In this review, we described the use of in situ imaging techniques to detect oxidative DNA damage including the comet assay. We will review our previous work that describes the utility of an antibody fragment (Fab) engineered to recognize 8-oxoG in DNA. Furthermore, we will discuss the analysis of DNA repair enzymes in the assessment of oxidative DNA damage. Finally, advantages and potential concerns associated with immunodetection of 8-oxoG are discussed.
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Affiliation(s)
- R L Persinger
- University of Vermont College of Medicine, Department of Pathology, Burlington, Vermont, VT 05405, USA
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