TY - JOUR A1 - Hahn, Marc Benjamin A1 - Dietrich, P. M. A1 - Radnik, Jörg T1 - In situ monitoring of the influence of water on DNA radiation damage by near-ambient pressure X-ray photoelectron spectroscopy N2 - 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 xperiments 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. KW - DNA KW - XPS KW - NAP-XPS KW - Radiation damage KW - Single-strand break (SSB) KW - Double-strand break (DSB) KW - Xray KW - OH radical KW - Hydroxyl radical KW - LEE KW - Low energy electrons KW - Dosimetry KW - Geant4 KW - Geant4-DNA KW - TOPAS KW - TOPAS-nbio KW - Microdosimetry KW - DNA radiation damage KW - Direct damage KW - Indirect damage KW - Quasi-direct damage KW - Hydration shell KW - Dry DNA KW - Hydrated DNA KW - ROS KW - Radical KW - Reactive oxygen species KW - Net-ionization reaction KW - Radiation therapy KW - Cancer therapy KW - Xray photo electron spectrocopy KW - Near ambient pressure xray photo electron spectroscopy KW - Base damage KW - Base loss KW - Dissociative electron transfer (DET) KW - Dissociative electron attachment (DEA) KW - Hydrated electron KW - Prehydrated electron KW - Ionization KW - PES PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-524060 DO - https://doi.org/10.1038/s42004-021-00487-1 SN - 2399-3669 VL - 4 IS - 1 SP - 50 PB - Springer Nature CY - London AN - OPUS4-52406 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hahn, Marc Benjamin A1 - Dietrich, P. M. A1 - Radnik, Jörg T1 - The change of DNA radiation damage upon hydration: In-situ observations by near-ambient-pressure XPS N2 - 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. T2 - #RSCposter 2023 CY - Online meeting DA - 28.02.2023 KW - Cancer treatment KW - DNA KW - Dosimetry KW - Energy deposit KW - Geant4 KW - Geant4-DNA KW - TOPAS KW - TOPAS-nbio KW - particle scattering KW - Simulation KW - Radiolysis KW - Radiation therapy KW - Radiotherapy KW - LEE KW - Low energy electrons KW - MCS KW - Base damage KW - Base loss KW - DNA radiation damage KW - Direct damage KW - Dissociative electron transfer (DET) KW - Dissociative electron attachment (DEA) KW - Double-strand break (DSB) KW - Hydrated DNA KW - Hydrated electron KW - Ionization KW - Hydration shell KW - Hydroxyl radical KW - Indirect damage KW - Microdosimetry KW - NAP-XPS KW - Near ambient pressure xray photo electron spectroscopy KW - Net-ionization reaction KW - OH radical KW - PES KW - Prehydrated electron KW - Quasi-direct damage KW - Radiation damage KW - Radical KW - Reactive oxygen species KW - ROS KW - Single-strand break (SSB) KW - XPS KW - Xray KW - Xray photo electron spectrocopy KW - presolvated electron PY - 2023 UR - https://www.nature.com/articles/s42004-021-00487-1 AN - OPUS4-57063 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hahn, Marc Benjamin A1 - Hallier, Dorothea C. A1 - Smales, Glen Jacob A1 - Seitz, H. T1 - Extending Bio-SAXS measurements of Single-Stranded DNA-Binding Proteins: Radiation Protection of G5P by Cosolutes N2 - Small-angle X-ray scattering (SAXS) can be used for structural de- termination of biological macromolecules and polymers in their na- tive states. To improve the reliability of such experiments, the re- duction of radiation damage occurring from exposure to X-rays is needed.One method, is the use of scavenger molecules that protect macromolecules against radicals produced by radiation exposure.In this study we investigate the feasibility to apply the compatible solute, osmolyte and radiation protector Ectoine (THP(B)) as a scavenger throughout SAXS measurements of single-stranded DNA-binding protein Gene-V Protein (G5P/GVP). Therefore we monitor the radiation induced changes of G5P during bio-SAXS. The resulting microscopic energy-damage relation was determined by particle scattering simu- lations with TOPAS/Geant4. The results are interpreted in terms of radical scavenging as well as post-irradiation effects, related to preferential-exclusion from the protein surface. Thus, Ectoine provides an non-disturbing way to improve structure-determination of proteins via bio-SAXS in future studies. T2 - MultiChem Conference 2023 CY - Prague, Czech Republic DA - 26.04.2023 KW - Bio-SAXS KW - BioSAXS KW - Compatible solute KW - Cosolute KW - DNA KW - Dosimetry KW - Ectoin KW - Ectoine KW - Ectoin KW - G5P KW - GVP KW - Geant4 KW - Geant4-DNA KW - Gene five protein KW - Hydroxyectoine KW - Ionizing radiation damage KW - LEE KW - McSAS3 KW - Microdosimetry KW - Monte-Carlo simulations KW - OH Radical KW - OH radical scavenger KW - Osmolyte KW - Particle scattering simulations KW - Protein KW - Protein unfolding KW - Proteins KW - ROS KW - Radiation damage KW - Radical Scavenger KW - Radical scavenger KW - SAXS KW - Single-stranded DNA-binding proteins KW - Small-angle xray scattering KW - Topas KW - Topas-MC KW - Topas-nBio KW - X-ray scattering KW - ssDNA KW - Median lethal energy deposit PY - 2023 AN - OPUS4-57407 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hallier, Dorothea C. A1 - Smales, Glen Jacob A1 - Seitz, H. A1 - Hahn, Marc Benjamin T1 - Inside back cover for the article "Bio-SAXS of single-stranded DNA-binding proteins: Radiation protection by the compatible solute ectoine" N2 - Showcasing research from the Federal Institute for Material Research and Testing Berlin and Fraunhofer Institute for Celltherapy and Immunology Branch Bioanalytics and Bioprocesses Potsdam. Bio-SAXS of single-stranded DNA-binding proteins: Radiation protection by the compatible solute ectoine. We aimed to increase the possible undisturbed exposure time during bio-SAXS measurements of single-stranded DNA-binding proteins. Therefore small angle X-ray scattering was performed on Gene-V Protein (G5P/GVP), which is involved in DNA repair processes. To achieve this, irradiations were performed in presence and absence of the hydroxyl-radical scavenger and osmolyte Ectoine, which showed efficient radiation protection and prevented protein aggregation, thus allows for a non-disturbing way to improve structure-determination of biomolecules. KW - Bio-SAXS KW - BioSAXS KW - Cosolute KW - DNA KW - Dosimetry KW - Ectoin KW - Ectoine KW - G5P KW - GVP KW - Geant4 KW - Geant4-DNA KW - Ionizing radiation damage KW - LEE KW - McSAS3 KW - Microdosimetry KW - Monte-Carlo simulations KW - OH Radical KW - OH radical scavenger KW - Protein KW - Protein unfolding KW - Radiation damage KW - Radical Scavenger KW - SAXS KW - Single-stranded DNA-binding proteins KW - Small-angle xray scattering KW - Topas-MC KW - Topas-nBio KW - TopasMC KW - X-ray scattering KW - Particle scatterin simulations KW - ssDNA PY - 2023 DO - https://doi.org/10.1039/D3CP90056H SN - 1463-9076 SN - 1463-9084 VL - 25 IS - 7 SP - 5889 PB - Royal Society of Chemistry CY - Cambridge AN - OPUS4-57006 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hahn, Marc Benjamin T1 - Radiation biophysics N2 - We give an overview about our work related to radiation damage to DNA, proteins, and DNA-protiren complexes damage. Hereby the focus lies on the combination of experiments and Geant4 particle scattering simulations to understand effects in plasmid DNA pUC19, Oligos, and G5P protein. T2 - Project overview CY - Berlin, Germany DA - 27.09.2023 KW - DNA KW - Dosimetry KW - Proteins KW - Radiation damage KW - G5P KW - Microdosimetry KW - Ionizing radiation KW - Geant4 KW - TOPAS KW - TOPAS-nBio KW - Geant4-DNA KW - LEE KW - OH KW - Hydroxyl radical PY - 2023 AN - OPUS4-58742 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hahn, Marc Benjamin A1 - Zutta Villate, J. M. ED - Zutta Villate, J. M. T1 - Combined cell and nanoparticle models for TOPAS to study radiation dose enhancement in cell organelles N2 - 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. KW - AuNP KW - Beta decay KW - Brachytherapy KW - Cancer treatment KW - DNA KW - DNA damage KW - Dosimetry KW - Energy deposit KW - Geant4 KW - Geant4-DNA KW - Gold Nanoparticles KW - LEE KW - MCS KW - Microdosimetry KW - Monte-Carlo simulation KW - NP KW - Ectoine KW - OH radicals KW - Radiation damage KW - Radiationtherapy KW - Radioactive decay KW - Simulation KW - Beta particle KW - Clustered nanoparticles KW - Gamma ray KW - Low energy electrons KW - Particle scattering KW - Radiolysis KW - Livermore model KW - Penelope model KW - TOPAS KW - TOPAS-nbio PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-523276 DO - https://doi.org/10.1038/s41598-021-85964-2 SN - 2045-2322 VL - 11 IS - 1 SP - 6721 PB - Springer Nature AN - OPUS4-52327 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Hahn, Marc Benjamin T1 - BioSAXS models for TOPAS/Geant4 N2 - Models for TOPAS/Geant4 to estimate the microscopic dose received by biomolecules during bioSAXS experiments. The C++ classes in this repository extend the functionality of the TOPAS (http://www.topasmc.org/) Monte-Carlo program, which is itself a wrapper of the Geant4 MCS Toolkit (http://geant4.org). KW - TOPAS KW - TOPAS-nBio KW - Geant4 KW - Geant4-DNA KW - MCS KW - Microdosimetry KW - Protein KW - Proteins KW - Particle scattering KW - G5P KW - GV5 KW - SAXS KW - Monte-Carlo simulation KW - Dosimetry KW - Micorscopic dose-damage relation PY - 2022 UR - https://github.com/MarcBHahn/TOPAS-bioSAXS-dosimetry DO - https://doi.org/10.26272/opus4-55751 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-55751 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hahn, Marc Benjamin A1 - Dietrich, P. M. A1 - Radnik, Jörg A1 - Solomun, Tihomir A1 - Hallier, Dorothea C. A1 - Seitz, H. T1 - The change of dna and protein radiation damage upon hydration: in-situ observations by near-ambient-pressure xps N2 - 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. Our 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. Furthermore, first data about the degradation of single-stranded DNA binding-proteins (G5P / GV5 and hmtSSB) under vacuum and NAP-XPS conditions are presented. T2 - AVS69 CY - Portland, USA DA - 05.11.2023 KW - Base damage KW - Base loss KW - Cancer treatment KW - DNA KW - Protein KW - Proteins KW - Geant4 KW - Dosimetry KW - Microdosimetry KW - NAP-XPS KW - Xray photo electron spectrocopy KW - Radiation damage KW - Geant4-DNA KW - G5P KW - GVP KW - Hydroxyl radical KW - LEE KW - DEA KW - DET KW - ROS KW - Prehydrated electron KW - TOPAS KW - Near ambient pressure xray photo electron spectroscopy KW - SSB KW - DSB KW - Single-strand break (SSB) KW - ESCA KW - Single-stranded DNA-binding proteins KW - Reactive oxygen species PY - 2023 AN - OPUS4-58761 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hahn, Marc Benjamin T1 - Radiation biophysics: a journey N2 - We give an overview about recent work concerning ionizing radiation damage to Oligonucleotides, plasmid DNA, DNA binding proteins (G5P), and DNA-protein complexes. We focus on combining new experimental setups with Geant4/TOPAS particle scattering simulations to understand the effets of ionizing radiation. T2 - Project update CY - Online meeting DA - 09.10.2023 KW - DNA KW - Proteins KW - G5P KW - Geant4 KW - Geant4-DNA KW - TOPAS KW - TOPAS-nBio KW - LEE KW - Dosimetry KW - Microdosimetry KW - Magnetism KW - Protein PY - 2023 AN - OPUS4-58744 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hahn, Marc Benjamin A1 - Meyer, Susan A1 - Solomun, Tihomir A1 - Kunte, Hans-Jörg A1 - Sturm, Heinz T1 - Electron irradiation of biomolecules under physiological conditions: Experimental realization and microdosimetric calculations N2 - In the last years, secondary low-energy electrons (LEE) emerged as important, if not predominant, reductive pathway in ionizing damage of biomolecules. These electrons are created in copious amount as result of inelastic scattering of high energy radiation at water. Until now, all experiments the quantification of the effects of LEEs on the biomolecular damage was either performed in vacuum with LEE sources or with DNA on surfaces in humid atmosphere. We present a new experimental setup to irradiate biomolecules with electrons under physiological conditions. In combination with monte carlo simulations this setup makes it possible to determine microdosimetric quantities for biomolecules in liquid environment under electron irradiation. This opens up new possibilities in radiation research to access the LEE damage under well defined physiological condition, for more complex systems, such as DNA-Protein complexes and even living cells. T2 - 14th International Congress of the International Radiation Protection Association CY - Cape Town, South Africa DA - 09.05.2016 KW - DNA KW - Dosimetry KW - Microdosimetry KW - Geant4 KW - Low energy electrons KW - Radicals KW - Radiation damage KW - Polymers PY - 2016 AN - OPUS4-36399 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -