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Hallier DC, Smales GJ, Seitz H, Hahn MB. Bio-SAXS of single-stranded DNA-binding proteins: radiation protection by the compatible solute ectoine. Phys Chem Chem Phys 2023; 25:5372-5382. [PMID: 36637121 DOI: 10.1039/d2cp05053f] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Small-angle X-ray scattering (SAXS) can be used for structural determination of biological macromolecules and polymers in their native states (e.g. liquid phase). This means that the structural changes of (bio-)polymers, such as proteins and DNA, can be monitored in situ to understand their sensitivity to changes in chemical environments. In an attempt to improve the reliability of such experiments, the reduction of radiation damage occurring from exposure to X-rays is required. One such method, is to use scavenger molecules to protect macromolecules against radicals produced during radiation exposure, such as reactive oxygen species (ROS). In this study we investigate the feasibility of applying the compatible solute, osmolyte and radiation protector Ectoine (THP(B)), as a scavenger molecule during SAXS measurements of the single-stranded DNA-binding protein Gene-V Protein (G5P/GVP). In this case, we monitor the radiation induced changes of G5P during bio-SAXS measurments and the resulting microscopic energy-damage relation was determined from microdosimetric calculations by Monte-Carlo based particle scattering simulations with TOPAS/Geant4 and a custom target-model. This resulted in a median-lethal energy deposit of pure G5P at 4 mg mL-1 of E1/2 = 7 ± 5 eV, whereas a threefold increase of energy-deposit was needed under the presence of Ectoine to reach the same level of damage. This indicates that Ectoine increases the possible exposure time before radiation-damage to G5P is observed. Furthermore, the dominant type of damage shifted from aggregation in pure solutions towards a fragmentation for solutions containing Ectoine as a cosolute. These results are interpreted in terms of indirect radiation damage by reactive secondary species, as well as post-irradiation effects, related to preferential-exclusion of the cosolute from the protein surface. Hence, Ectoine is shown to provide a non-disturbing way to improve structure-determination of proteins via bio-SAXS in future studies.
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Affiliation(s)
- Dorothea C Hallier
- Universität Potsdam, Institut für Biochemie und Biologie, 14476 Potsdam, Germany.,Fraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytics and Bioprocesses (IZI-BB), 14476 Potsdam, Germany.,Bundesanstalt für Materialforschung und -prüfung (BAM), 12205 Berlin, Germany.
| | - Glen J Smales
- Bundesanstalt für Materialforschung und -prüfung (BAM), 12205 Berlin, Germany.
| | - Harald Seitz
- Universität Potsdam, Institut für Biochemie und Biologie, 14476 Potsdam, Germany.,Fraunhofer Institute for Cell Therapy and Immunology, Branch Bioanalytics and Bioprocesses (IZI-BB), 14476 Potsdam, Germany
| | - Marc Benjamin Hahn
- Bundesanstalt für Materialforschung und -prüfung (BAM), 12205 Berlin, Germany.
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2
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Liu G. Revision of cytogenetic dosimetry in the IAEA manual 2011 based on data about radio-sensitivity and dose-rate findings contributing. FASEB J 2022; 36:e22621. [PMID: 36260291 DOI: 10.1096/fj.202200769rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 08/31/2022] [Accepted: 10/10/2022] [Indexed: 11/11/2022]
Abstract
In order to achieve the goal of rapid response, effective controland protection of life inlarge-scale radiation events, the IAEA Manual 2011 has been revised based on the data of radio-sensitivity, dose-rate findings. Analyze individual differences in radiation sensitivity using 60 Co radiation (0.27 Gy/min). Chromosomal aberrations with different irradiation dose rates were used to establish the biological dose curve and analyze the excess of the "dicentric + ring" caused by the dose rate at each dose point; DAPI-images and Metafer 4 were used to capture metaphase images and make further analysis. The data were collected in 2020, Dicentric + ring/100 Cells was 17.5-43.8, the average value was28.32 ± 6.98. The mean value of Dicentric + ring/100 Cells was 31.37 in males while 25.27 in females, there are significant differences (p < .01). The irradiation dose is dominant, At each dose point, the value of"(dicentric chromosome + centric rings)/cell" is proportional to "dose rate", that is, Y = kx + b, within the dose range of 1-5 Gy, "(dicentric chromosome + centric rings)/Cell" holds a quadratic linear relationship with dose rate, that is, y = ax2 + bx + c; The DAPI-images might give you more hints than those of conventional Giemsa-stain. The authors recommend that the IAEA Manual 2011 could be revised based on data of radio-sensitivity and dose-rate, which may contribute to the establishment of a unified dose-response calibration curve and stimulation of potential for automation in cytogenetic biodosimetry. (1) Individual differences of radiosensitivity are very large. (2) At each dose point, "(dicentric chromosome + centric rings)/cell" is proportional to "dose rate", that is, Y = kx + b. (3) "(dicentric chromosome + centric rings)/Cell" is a quadratic linear relationship with dose rate, that is, y = ax2 + bx + c. (4) We created a "Unity Standard Curve of Biological Dose Estimation". Creating a Unity Standard Curve of Biological Dose, under these circumstances, we can form a joint and rapid response to a nuclear and radiological accident.
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Affiliation(s)
- Gang Liu
- Gansu Provincial Center for Disease Control and Prevention, Joint Laboratory of Institute of Radiology, Chinese Academy of Medical Sciences, Lanzhou, China
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3
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Villate JMZ, Rojas JV, Hahn MB, Puerta JA. Synthesis of 198Au nanoparticles sub 10 nm due optimization on local dose by Monte Carlo simulations for cancer treatment. J Radioanal Nucl Chem 2022. [DOI: 10.1007/s10967-022-08355-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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4
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Gao Y, Zheng Y, Sanche L. Low-Energy Electron Damage to Condensed-Phase DNA and Its Constituents. Int J Mol Sci 2021; 22:7879. [PMID: 34360644 PMCID: PMC8345953 DOI: 10.3390/ijms22157879] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 06/30/2021] [Accepted: 06/30/2021] [Indexed: 11/18/2022] Open
Abstract
The complex physical and chemical reactions between the large number of low-energy (0-30 eV) electrons (LEEs) released by high energy radiation interacting with genetic material can lead to the formation of various DNA lesions such as crosslinks, single strand breaks, base modifications, and cleavage, as well as double strand breaks and other cluster damages. When crosslinks and cluster damages cannot be repaired by the cell, they can cause genetic loss of information, mutations, apoptosis, and promote genomic instability. Through the efforts of many research groups in the past two decades, the study of the interaction between LEEs and DNA under different experimental conditions has unveiled some of the main mechanisms responsible for these damages. In the present review, we focus on experimental investigations in the condensed phase that range from fundamental DNA constituents to oligonucleotides, synthetic duplex DNA, and bacterial (i.e., plasmid) DNA. These targets were irradiated either with LEEs from a monoenergetic-electron or photoelectron source, as sub-monolayer, monolayer, or multilayer films and within clusters or water solutions. Each type of experiment is briefly described, and the observed DNA damages are reported, along with the proposed mechanisms. Defining the role of LEEs within the sequence of events leading to radiobiological lesions contributes to our understanding of the action of radiation on living organisms, over a wide range of initial radiation energies. Applications of the interaction of LEEs with DNA to radiotherapy are briefly summarized.
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Affiliation(s)
- Yingxia Gao
- State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University, Fuzhou 350116, China;
| | - Yi Zheng
- State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University, Fuzhou 350116, China;
| | - Léon Sanche
- Département de Médecine Nucléaire et Radiobiologie et Centre de Recherche Clinique, Faculté de Médecine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada;
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5
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Hahn MB, Dietrich PM, Radnik J. In situ monitoring of the influence of water on DNA radiation damage by near-ambient pressure X-ray photoelectron spectroscopy. Commun Chem 2021; 4:50. [PMID: 36697687 PMCID: PMC9814248 DOI: 10.1038/s42004-021-00487-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 03/10/2021] [Indexed: 02/01/2023] Open
Abstract
Ionizing radiation damage to DNA plays a fundamental role in cancer therapy. X-ray photoelectron-spectroscopy (XPS) allows simultaneous irradiation and damage monitoring. Although water radiolysis is essential for radiation damage, all previous XPS studies were performed in vacuum. Here we present near-ambient-pressure XPS experiments to directly measure DNA damage under water atmosphere. They permit in-situ monitoring of the effects of radicals on fully hydrated double-stranded DNA. The results allow us to distinguish direct damage, by photons and secondary low-energy electrons (LEE), from damage by hydroxyl radicals or hydration induced modifications of damage pathways. The exposure of dry DNA to x-rays leads to strand-breaks at the sugar-phosphate backbone, while deoxyribose and nucleobases are less affected. In contrast, a strong increase of DNA damage is observed in water, where OH-radicals are produced. In consequence, base damage and base release become predominant, even though the number of strand-breaks increases further.
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Affiliation(s)
- Marc Benjamin Hahn
- grid.14095.390000 0000 9116 4836Institut für Experimentalphysik, Freie Universität Berlin, Berlin, Germany ,grid.71566.330000 0004 0603 5458Bundesanstalt für Materialforschung und -prüfung, Berlin, Germany
| | | | - Jörg Radnik
- grid.71566.330000 0004 0603 5458Bundesanstalt für Materialforschung und -prüfung, Berlin, Germany
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6
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Combined cell and nanoparticle models for TOPAS to study radiation dose enhancement in cell organelles. Sci Rep 2021; 11:6721. [PMID: 33762596 PMCID: PMC7990972 DOI: 10.1038/s41598-021-85964-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 03/09/2021] [Indexed: 12/17/2022] Open
Abstract
Dose enhancement by gold nanoparticles (AuNP) increases the biological effectiveness of radiation damage in biomolecules and tissue. To apply them effectively during cancer therapy their influence on the locally delivered dose has to be determined. Hereby, the AuNP locations strongly influence the energy deposit in the nucleus, mitochondria, membrane and the cytosol of the targeted cells. To estimate these effects, particle scattering simulations are applied. In general, different approaches for modeling the AuNP and their distribution within the cell are possible. In this work, two newly developed continuous and discrete-geometric models for simulations of AuNP in cells are presented. These models are applicable to simulations of internal emitters and external radiation sources. Most of the current studies on AuNP focus on external beam therapy. In contrast, we apply the presented models in Monte-Carlo particle scattering simulations to characterize the energy deposit in cell organelles by radioactive 198AuNP. They emit beta and gamma rays and are therefore considered for applications with solid tumors. Differences in local dose enhancement between randomly distributed and nucleus targeted nanoparticles are compared. Hereby nucleus targeted nanoparticels showed a strong local dose enhancement in the radio sensitive nucleus. These results are the foundation for future experimental work which aims to obtain a mechanistic understanding of cell death induced by radioactive 198Au.
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Hahn MB, Smales GJ, Seitz H, Solomun T, Sturm H. Ectoine interaction with DNA: influence on ultraviolet radiation damage. Phys Chem Chem Phys 2020; 22:6984-6992. [PMID: 32188961 DOI: 10.1039/d0cp00092b] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Ectoine is a small zwitterionic osmolyte and compatible solute, which does not interfere with cell metabolism even at molar concentrations. Plasmid DNA (pUC19) was irradiated with ultraviolet radiation (UV-C at 266 nm) under quasi physiological conditions (PBS) and in pure water in the presence and absence of ectoine (THP(B)) and hydroxyectoine (THP(A)). Different types of UV induced DNA damage were analysed: DNA single-strand breaks (SSBs), abasic sites and cyclobutane pyrimidine dimers (CPDs). A complex interplay between these factors was observed with respect to the nature and occurrence of DNA damage with 266 nm photons. In PBS, the cosolutes showed efficient protection against base damage, whilst in pure water, a dramatic shift from SSB damage to base damage was observed when cosolutes were added. To test whether these effects are caused by ectoine binding to DNA, further experiments were conducted: small-angle X-ray scattering (SAXS), surface-plasmon resonance (SPR) measurements and Raman spectroscopy. The results show, for the first time, a close interaction between ectoine and DNA. This is in stark contrast to the assumption made by preferential exclusion models, which are often used to interpret the behaviour of compatible solutes within cells and with biomolecules. It is tentatively proposed that the alterations of UV damage to DNA are attributed to ectoine influence on nucleobases through the direct interaction between ectoine and DNA.
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Affiliation(s)
- Marc Benjamin Hahn
- Freie Universität Berlin, Institut für Experimentalphysik, 14195 Berlin, Germany. and Bundesanstalt für Materialforschung und -prüfung (BAM), 12205 Berlin, Germany
| | - Glen J Smales
- Bundesanstalt für Materialforschung und -prüfung (BAM), 12205 Berlin, Germany
| | - Harald Seitz
- Universität Potsdam, Institut für Biochemie und Biologie, 14476 Potsdam, Germany and Fraunhofer Institute for Cell Therapy and Immunology, 14476 Potsdam, Germany
| | - Tihomir Solomun
- Bundesanstalt für Materialforschung und -prüfung (BAM), 12205 Berlin, Germany
| | - Heinz Sturm
- Bundesanstalt für Materialforschung und -prüfung (BAM), 12205 Berlin, Germany
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8
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Determination of fast neutron RBE using a fully mechanistic computational model. Appl Radiat Isot 2020; 156:108952. [DOI: 10.1016/j.apradiso.2019.108952] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 10/11/2019] [Accepted: 10/21/2019] [Indexed: 11/19/2022]
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9
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Zabihi A, Incerti S, Francis Z, Forozani G, Semsarha F, Moslehi A, Rezaeian P, Bernal MA. Computational approach to determine the relative biological effectiveness of fast neutrons using the Geant4-DNA toolkit and a DNA atomic model from the Protein Data Bank. Phys Rev E 2019; 99:052404. [PMID: 31212425 DOI: 10.1103/physreve.99.052404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Indexed: 11/07/2022]
Abstract
This study proposes an innovative approach to estimate relative biological effectiveness (RBE) of fast neutrons using the Geant4 toolkit. The Geant4-DNA version cannot track heavy ions below 0.5 MeV/nucleon. In order to explore the impact of this issue, secondary particles are simulated instead of the primary low-energy neutrons. The Evaluated Nuclear Data File library is used to determine the cross sections for the elastic and inelastic interactions of neutrons with water and to find the contribution of each secondary particle spectrum. Two strategies are investigated in order to find the best possible approach and results. The first one takes into account only light particles, protons produced from elastic scattering, and α particles from inelastic scattering. Geantino particles are shot instead of heavy ions; hence all heavy ions are considered in the simulations, though their physical effects on DNA not. The second strategy takes into account all the heavy and light ions, although heavy ions cannot be tracked down to very low energies (E<0.5 MeV/nucleon). Our model is based on the combination of an atomic resolution DNA geometrical model and a Monte Carlo simulation toolkit for tracking particles. The atomic coordinates of the DNA double helix are extracted from the Protein Data Bank. Since secondary particle spectra are used instead of simulating the interaction of neutrons explicitly, this method reduces the computation times dramatically. Double-strand break induction is used as the end point for the estimation of the RBE of fast neutrons. ^{60}Co γ rays are used as the reference radiation quality. Both strategies succeed in reproducing the behavior of the RBE_{max} as a function of the incident neutron energy ranging from 0.1 to 14 MeV, including the position of its peak. A comparison of the behavior of the two strategies shows that for neutrons with energies less than 0.7 MeV, the effect of heavy ions would not be very significant, but above 0.7 MeV, heavy ions have an important role in neutron RBE.
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Affiliation(s)
- Azam Zabihi
- Department of Physics, Faculty of Science, Bu-Ali Sina University, Hamedan 651744161, Iran
| | - Sebastien Incerti
- University of Bordeaux, CENBG, UMR No. 5797, 33170 Gradignan, France CNRS, IN2P3, CENBG, UMR No. 5797, 33170 Gradignan, France
| | - Ziad Francis
- Department of Physics, Faculty of Sciences, Université Saint Joseph, 2020 1104 Beirut, Lebanon
| | - Ghasem Forozani
- Department of Physics, Payame Noor University, P.O. Box 19395-3697, Tehran, Iran
| | - Farid Semsarha
- Institute of Biochemistry and Biophysics, University of Tehran, P.O. Box 13145-1384, Tehran, Iran
| | - Amir Moslehi
- Radiation Applications Research School, Nuclear Science and Technology Research Institute, P.O. Box 11365-3486, Tehran, Iran
| | - Peiman Rezaeian
- Radiation Applications Research School, Nuclear Science and Technology Research Institute, P.O. Box 11365-3486, Tehran, Iran
| | - Mario A Bernal
- Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, Campinas, 13083-859 São Paulo, Brazil
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10
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Versteegen M, Raymond X, Gobet F, Henares JL. Role of the pre-plasma on electron beam currents from a biased laser-plasma. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:053306. [PMID: 31153274 DOI: 10.1063/1.5093592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 05/09/2019] [Indexed: 06/09/2023]
Abstract
We are investigating laser-plasmas produced in the interaction of a 1 J 9 ns Nd:YAG laser with a solid metal target as a source of electrons. An electron beam pulsed at the laser repetition rate is produced by biasing the target and making the plasma expand in an electric field. In this paper, we focus on the measured beam currents and charge surface distribution of the beam. The peak beam currents are much higher than what is given by a simplified toy model based on the Child-Langmuir limit in a vacuum and the charge surface distributions are inhomogeneous. Both these observations are explained by the presence of a positive preplasma expanding ahead of the laser-plasma front edge.
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Affiliation(s)
- Maud Versteegen
- Université de Bordeaux, CNRS-IN2P3, CENBG, F-33175 Gradignan, France
| | - Xavier Raymond
- Université de Bordeaux, CNRS-IN2P3, CENBG, F-33175 Gradignan, France
| | - Franck Gobet
- Université de Bordeaux, CNRS-IN2P3, CENBG, F-33175 Gradignan, France
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11
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Savchenko A, Sergeeva D, Tishchenko A, Strikhanov M. Small-angle x-ray transition radiation from multilayered structures. Int J Clin Exp Med 2019. [DOI: 10.1103/physrevd.99.016015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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12
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Mokari M, Alamatsaz MH, Moeini H, Babaei-Brojeny AA, Taleei R. Track structure simulation of low energy electron damage to DNA using Geant4-DNA. Biomed Phys Eng Express 2018. [DOI: 10.1088/2057-1976/aae02e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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13
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Sutter P, Zhang B, Sutter E. Radiation damage during in situ electron microscopy of DNA-mediated nanoparticle assemblies in solution. NANOSCALE 2018; 10:12674-12682. [PMID: 29946623 DOI: 10.1039/c8nr04087g] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Oligonucleotide-nanoparticle conjugates, also called programmable atom equivalents, carry promise as building blocks for self-assembled colloidal crystals, reconfigurable or stimuli responsive functional materials, as well as bio-inspired hierarchical architectures in wet environments. In situ studies of the DNA-mediated self-assembly of nanoparticles have so far been limited to reciprocal space techniques. Liquid-cell electron microscopy could enable imaging such systems with high resolution in their native environment but to realize this potential, radiation damage to the oligonucleotide linkages needs to be understood and conditions for damage-free electron microscopy identified. Here, we analyze in situ observations of DNA-linked two-dimensional nanoparticle arrays, along with control experiments for different oligonucleotide configurations, to identify the mechanisms of radiation damage for ordered superlattices of DNA-nanoparticle conjugates. In a biological context, the results point to new avenues for studying direct and indirect radiation effects for small ensembles of DNA in solution by tracking conjugated nanoparticles. By establishing low-dose conditions suitable for extended in situ imaging of programmable atom equivalents, our work paves the way for real-space observations of DNA-mediated self-assembly processes.
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Affiliation(s)
- Peter Sutter
- Department of Electrical & Computer Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, USA.
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14
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Schürmann R, Vogel S, Ebel K, Bald I. The Physico-Chemical Basis of DNA Radiosensitization: Implications for Cancer Radiation Therapy. Chemistry 2018. [PMID: 29522244 DOI: 10.1002/chem.201800804] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
High-energy radiation is used in combination with radiosensitizing therapeutics to treat cancer. The most common radiosensitizers are halogenated nucleosides and cisplatin derivatives, and recently also metal nanoparticles have been suggested as potential radiosensitizing agents. The radiosensitizing action of these compounds can at least partly be ascribed to an enhanced reactivity towards secondary low-energy electrons generated along the radiation track of the high-energy primary radiation, or to an additional emission of secondary reactive electrons close to the tumor tissue. This is referred to as physico-chemical radiosensitization. In this Concept article we present current experimental methods used to study fundamental processes of physico-chemical radiosensitization and discuss the most relevant classes of radiosensitizers. Open questions in the current discussions are identified and future directions outlined, which can lead to optimized treatment protocols or even novel therapeutic concepts.
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Affiliation(s)
- Robin Schürmann
- Institute of Chemistry-Physical Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany.,Department 1-Analytical Chemistry and Reference Materials, BAM Federal Institute for Materials Research and Testing, Richard-Willstätter Str. 11, 12489, Berlin, Germany
| | - Stefanie Vogel
- Institute of Chemistry-Physical Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany.,Department 1-Analytical Chemistry and Reference Materials, BAM Federal Institute for Materials Research and Testing, Richard-Willstätter Str. 11, 12489, Berlin, Germany.,School of Analytical Sciences Adlershof, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099, Berlin, Germany
| | - Kenny Ebel
- Institute of Chemistry-Physical Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany.,Department 1-Analytical Chemistry and Reference Materials, BAM Federal Institute for Materials Research and Testing, Richard-Willstätter Str. 11, 12489, Berlin, Germany
| | - Ilko Bald
- Institute of Chemistry-Physical Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany.,Department 1-Analytical Chemistry and Reference Materials, BAM Federal Institute for Materials Research and Testing, Richard-Willstätter Str. 11, 12489, Berlin, Germany
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15
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Hahn MB, Meyer S, Schröter MA, Kunte HJ, Solomun T, Sturm H. DNA protection by ectoine from ionizing radiation: molecular mechanisms. Phys Chem Chem Phys 2018; 19:25717-25722. [PMID: 28913528 DOI: 10.1039/c7cp02860a] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Ectoine, a compatible solute and osmolyte, is known to be an effective protectant of biomolecules and whole cells against heating, freezing and extreme salinity. Protection of cells (human keratinocytes) by ectoine against ultraviolet radiation has also been reported by various authors, although the underlying mechanism is not yet understood. We present the first electron irradiation of DNA in a fully aqueous environment in the presence of ectoine and at high salt concentrations. The results demonstrate effective protection of DNA by ectoine against the induction of single-strand breaks by ionizing radiation. The effect is explained by an increase in low-energy electron scattering at the enhanced free-vibrational density of states of water due to ectoine, as well as the use of ectoine as an ˙OH-radical scavenger. This was demonstrated by Raman spectroscopy and electron paramagnetic resonance (EPR).
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Affiliation(s)
- Marc Benjamin Hahn
- Free University Berlin, Department of Physics, D-14195 Berlin, Germany. and Bundesanstalt für Materialforschung und Prüfung, D-12205 Berlin, Germany.
| | - Susann Meyer
- Bundesanstalt für Materialforschung und Prüfung, D-12205 Berlin, Germany. and University of Potsdam, Institute of Biochemistry and Biology, D-14476 Potsdam, Germany
| | | | - Hans-Jörg Kunte
- Bundesanstalt für Materialforschung und Prüfung, D-12205 Berlin, Germany.
| | - Tihomir Solomun
- Bundesanstalt für Materialforschung und Prüfung, D-12205 Berlin, Germany.
| | - Heinz Sturm
- Bundesanstalt für Materialforschung und Prüfung, D-12205 Berlin, Germany. and Technical University Berlin, D-10587 Berlin, Germany
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