TY  - JOUR
A1  - Schürmann, Robin Mathis
A1  - Vogel, Stefanie
A1  - Ebel, Kenny
A1  - Bald, Ilko
T1  - The physico-chemical basis of DNA radiosensitization
BT  - implications for cancer radiation therapy
JF  - Chemistry - a European journal
N2  - 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.
KW  - cancer
KW  - dissociative electron attachment
KW  - low-energy electrons
KW  - radiation therapy
KW  - radiosensitizers
Y1  - 2018
U6  - https://doi.org/10.1002/chem.201800804
SN  - 0947-6539
SN  - 1521-3765
VL  - 24
IS  - 41
SP  - 10271
EP  - 10279
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Schürmann, Robin Mathis
A1  - Tsering, Thupten
A1  - Tanzer, Katrin
A1  - Denifl, Stephan
A1  - Kumar, S. V. K.
A1  - Bald, Ilko
T1  - Resonant Formation of Strand Breaks in Sensitized Oligonucleotides Induced by Low-Energy Electrons (0.5-9 eV)
JF  - Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker ; International edition
N2  - Halogenated nucleobases are used as radiosensitizers in cancer radiation therapy, enhancing the reactivity of DNA to secondary low-energy electrons (LEEs). LEEs induce DNA strand breaks at specific energies (resonances) by dissociative electron attachment (DEA). Although halogenated nucleobases show intense DEA resonances at various electron energies in the gas phase, it is inherently difficult to investigate the influence of halogenated nucleobases on the actual DNA strand breakage over the broad range of electron energies at which DEA can take place (<12 eV). By using DNA origami nanostructures, we determined the energy dependence of the strand break cross-section for oligonucleotides modified with 8-bromoadenine ((8Br)A). These results were evaluated against DEA measurements with isolated (8Br)A in the gas phase. Contrary to expectations, the major contribution to strand breaks is from resonances at around 7 eV while resonances at very low energy (<2 eV) have little influence on strand breaks.
KW  - cancer radiation therapy
KW  - dissociative electron attachment
KW  - DNA origami
KW  - DNA radiation damage
KW  - radiosensitizers
Y1  - 2017
U6  - https://doi.org/10.1002/anie.201705504
SN  - 1433-7851
SN  - 1521-3773
VL  - 56
SP  - 10952
EP  - 10955
PB  - Wiley-VCH
CY  - Weinheim
ER  -