@article{SchuermannVogelEbeletal.2018,
  author    = {Sch{\"u}rmann, Robin Mathis and Vogel, Stefanie and Ebel, Kenny and Bald, Ilko},
  title     = {The physico-chemical basis of DNA radiosensitization},
  series = {Chemistry - a European journal},
  volume    = {24},
  journal   = {Chemistry - a European journal},
  number    = {41},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0947-6539},
  doi       = {10.1002/chem.201800804},
  pages     = {10271 -- 10279},
  year      = {2018},
  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.},
  language  = {en}
}
@article{RackwitzBald2018,
  author    = {Rackwitz, Jenny and Bald, Ilko},
  title     = {Low-energy electron-induced strand breaks in telomere-derived DNA sequences},
  series = {Chemistry - a European journal},
  volume    = {24},
  journal   = {Chemistry - a European journal},
  number    = {18},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0947-6539},
  doi       = {10.1002/chem.201705889},
  pages     = {4680 -- 4688},
  year      = {2018},
  abstract  = {During cancer radiation therapy high-energy radiation is used to reduce tumour tissue. The irradiation produces a shower of secondary low-energy (<20 eV) electrons, which are able to damage DNA very efficiently by dissociative electron attachment. Recently, it was suggested that low-energy electron-induced DNA strand breaks strongly depend on the specific DNA sequence with a high sensitivity of G-rich sequences. Here, we use DNA origami platforms to expose G-rich telomere sequences to low-energy (8.8 eV) electrons to determine absolute cross sections for strand breakage and to study the influence of sequence modifications and topology of telomeric DNA on the strand breakage. We find that the telomeric DNA 5′-(TTA GGG)2 is more sensitive to low-energy electrons than an intermixed sequence 5′-(TGT GTG A)2 confirming the unique electronic properties resulting from G-stacking. With increasing length of the oligonucleotide (i.e., going from 5′-(GGG ATT)2 to 5′-(GGG ATT)4), both the variety of topology and the electron-induced strand break cross sections increase. Addition of K+ ions decreases the strand break cross section for all sequences that are able to fold G-quadruplexes or G-intermediates, whereas the strand break cross section for the intermixed sequence remains unchanged. These results indicate that telomeric DNA is rather sensitive towards low-energy electron-induced strand breakage suggesting significant telomere shortening that can also occur during cancer radiation therapy.},
  language  = {en}
}