Dokument-ID Dokumenttyp Autoren/innen Persönliche Herausgeber/innen Haupttitel Abstract Auflage Verlagsort Verlag Herausgeber (Institution) Erscheinungsjahr Titel des übergeordneten Werkes Jahrgang/Band ISBN Veranstaltung Veranstaltungsort Beginndatum der Veranstaltung Enddatum der Veranstaltung Ausgabe/Heft Erste Seite Letzte Seite URN DOI Lizenz Datum der Freischaltung OPUS4-55132 Zeitschriftenartikel Zutta Villate, J. M.; Viviana Rojas, J.; Hahn, Marc Benjamin; Anselmo Puerta, J. Synthesis of 198Au nanoparticles sub 10 nm due optimization on local dose by Monte Carlo simulations for cancer treatment To enhance the biological effects of radiation damage in cancerous cells, we present an alternative approach to the use of gold nanoparticles (AuNP), focusing on the synthesis and characterization of highly monodisperse, spherical radioactive gold nanoparticles 198AuNP. The size of the AuNP size was optimized with the help of Geant4/TOPAS particle scattering simulations, and energy deposition per nm3 per decay for varying radii (2-10 nm) was evaluated. This work is the foundation for ongoing experimental work to evaluate cell death induced by 198AuNP which aims for the use of radioactive gold nanoparticles in cancer treatment. Springer Nature Akadémiai Kiadó, Budapest, Hungary 2022 Journal of Radioanalytical and Nuclear Chemistry 1 9 10.1007/s10967-022-08355-5 2022-06-29 OPUS4-56123 Vortrag Hahn, Marc Benjamin What can we learn from polymer degradation by radiation? It is discussed what can be learned from polymer degradation, especially of biopolymers such as DNA and proteins. Synergetci effects of combining methods for structural and chemical analysis as well as Monte-Carlo simulations are presented. 2022 Material Strategy Beelitz, Germany 12.10.2022 2022-10-31 OPUS4-54775 Posterpräsentation Hahn, Marc Benjamin Combined cell and nanoparticle models for TOPAS to study radiation dose enhancement by Monte-Carlo based particle scattering Simulations 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.[1] 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. [2] 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 ongoing experimental work which aims to obtain a mechanistic understanding of cell death induced by radioactive 198Au. 2022 NALS 2022 Santander, Spain 27.04.2022 29.04.2022 2022-05-09 OPUS4-53894 Vortrag Hahn, Marc Benjamin Importance of Radiation Damage to DNA-Protein Complexes The formation of DNA-protein complexes ocurrs during replication and repair within cells. They are assumed to modify the damage caused by ionization radiation during radaition therapy. Hereby the assumption is, that the underlying damaging channels in DNA and proteins are modified, especially when compared to single molecules. 2021 Scientific online presentations workshop Online meeting 03.12.2021 03.12.2021 2021-12-08 OPUS4-53611 Vortrag Hahn, Marc Benjamin Near-Ambient-Pressure XPS to investigate radiation damage to DNA 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. 2021 Physical and Chemical Analysis of Polymers seminar Online meeting 12.10.2021 12.10.2021 2021-10-26 OPUS4-52154 Vortrag Hahn, Marc Benjamin Data processing and nonlinear curve Fitting with fityk A brief introduction into fityk is given. The introduction is followed by a pratical session. Fityk is a versatile data processing tool for nonlinear curve fitting. 2021 AFM Data analysis seminar Online meeting 23.02.2021 23.02.2021 2021-02-24 OPUS4-55714 Zeitschriftenartikel Cordsmeier, Leo; Hahn, Marc Benjamin DNA Stability in Biodosimetry, Pharmacy and DNA Based Data-Storage: Optimal Storage and Handling Conditions DNA long-term stability and integrity is of importance for applications in DNA based bio-dosimetry, data-storage, pharmaceutical quality-control, donor insemination and DNA based functional nanomaterials. Standard protocols for these applications involve repeated freeze-thaw cycles of the DNA, which can cause detrimental damage to the nucleobases, as well as the sugar-phosphate backbone and therefore the whole molecule. Throughout the literature three hypotheses can be found about the underlying mechanisms occurring during freeze-thaw cycles. It is hypothesized that DNA single-strand breaks during freezing can be induced by mechanical stress leading to shearing of the DNA molecule, by acidic pH causing damage through depurination and beta elimination or by the presence of metal ions catalyzing oxidative damage via reactive oxygen species (ROS). Here we test these hypotheses under well defined conditions with plasmid DNA pUC19 in high-purity buffer (1xPBS) at physiological salt and pH 7.4 conditions, under pH 6 and in the presence of metal ions in combination with the radical scavengers DMSO and Ectoine. The results show for the 2686 bp long plasmid DNA, that neither mechanical stress, nor pH 6 lead to degradation during repeated freeze-thaw cycles. In contrast, the presence of metal ions (Fe2+) leads to degradation of DNA via the production of radical species. Wiley-VCH GmbH Chemistry Europe European Chemical Societies Publishing 2022 ChemBioChem 1 9 urn:nbn:de:kobv:b43-557148 10.1002/cbic.202200391 https://creativecommons.org/licenses/by/4.0/deed.de 2022-09-15 OPUS4-55751 Forschungsdatensatz Hahn, Marc Benjamin BioSAXS models for TOPAS/Geant4 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). Berlin Bundesanstalt für Materialforschung und -prüfung (BAM) 2022 10.26272/opus4-55751 https://creativecommons.org/publicdomain/zero/1.0/deed.de 2022-09-28 OPUS4-56811 Forschungsdatensatz Smales, Glen Jacob; Hahn, Marc Benjamin; Hallier, Dorothea C.; Seitz, H. X-ray scattering datasets and simulations associated with the publication "Bio-SAXS of single-stranded DNA-binding proteins: Radiation protection by the compatible solute ectoine" This dataset contains the processed and analysed small-angle X-ray scattering data associated with all samples from the publications "Bio-SAXS of Single-Stranded DNA-Binding Proteins: Radiation Protection by the Compatible Solute Ectoine" (https://doi.org/10.1039/D2CP05053F). Files associated with McSAS3 analyses are included, alongside the relevant SAXS data, with datasets labelled in accordance to the protein (G5P), its concentration (1, 2 or 4 mg/mL), and if Ectoine is present (Ect) or absent (Pure). PEPSIsaxs simulations of the GVP monomer (PDB structure: 1GV5 ) and dimer are also included. TOPAS-bioSAXS-dosimetry extension for TOPAS-nBio based particle scattering simulations can be obtained from https://github.com/MarcBHahn/TOPAS-bioSAXS-dosimetry which is further described in https://doi.org/10.26272/opus4-55751. This work was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under grant number 442240902 (HA 8528/2-1 and SE 2999/2-1). We acknowledge Diamond Light Source for time on Beamline B21 under Proposal SM29806. This work has been supported by iNEXT-Discovery, grant number 871037, funded by the Horizon 2020 program of the European Commission. Geneva Zenodo Bundesanstalt für Materialforschung und -prüfung (BAM) 2023 10.5281/zenodo.7515394 https://creativecommons.org/licenses/by/4.0/deed.de 2023-01-10 OPUS4-56813 Vortrag Hahn, Marc Benjamin Functionalized biopolymers - using nature's toolbox Biopolymers are the building blocks of life. Their properties are exploited for material functionalization on the nanoscale in a flexible manner. An overview over current research activities in the field of sensing, nanostrcuturing, radiation damage measurements on DNA and proteins and microfluidics is given. 2022 Outreach talks Online meeting 24.11.2022 2023-01-10