@article{ScherzadMeyerKleinsasseretal.2017, author = {Scherzad, Agmal and Meyer, Till and Kleinsasser, Norbert and Hackenberg, Stephan}, title = {Molecular Mechanisms of Zinc Oxide Nanoparticle-Induced Genotoxicity Short Running Title: Genotoxicity of ZnO NPs}, series = {Materials}, volume = {10}, journal = {Materials}, number = {12}, doi = {10.3390/ma10121427}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-169948}, pages = {1427}, year = {2017}, abstract = {Background: Zinc oxide nanoparticles (ZnO NPs) are among the most frequently applied nanomaterials in consumer products. Evidence exists regarding the cytotoxic effects of ZnO NPs in mammalian cells; however, knowledge about the potential genotoxicity of ZnO NPs is rare, and results presented in the current literature are inconsistent. Objectives: The aim of this review is to summarize the existing data regarding the DNA damage that ZnO NPs induce, and focus on the possible molecular mechanisms underlying genotoxic events. Methods: Electronic literature databases were systematically searched for studies that report on the genotoxicity of ZnO NPs. Results: Several methods and different endpoints demonstrate the genotoxic potential of ZnO NPs. Most publications describe in vitro assessments of the oxidative DNA damage triggered by dissoluted Zn2+ ions. Most genotoxicological investigations of ZnO NPs address acute exposure situations. Conclusion: Existing evidence indicates that ZnO NPs possibly have the potential to damage DNA. However, there is a lack of long-term exposure experiments that clarify the intracellular bioaccumulation of ZnO NPs and the possible mechanisms of DNA repair and cell survival.}, language = {en} } @article{MeyerScherzadMoratinetal.2019, author = {Meyer, Till Jasper and Scherzad, Agmal and Moratin, Helena and Gehrke, Thomas Eckert and Killisperger, Julian and Hagen, Rudolf and Wohlleben, Gisela and Polat, B{\"u}lent and Dembski, Sofia and Kleinsasser, Norbert and Hackenberg, Stephan}, title = {The radiosensitizing effect of zinc oxide nanoparticles in sub-cytotoxic dosing is associated with oxidative stress in vitro}, series = {Materials}, volume = {12}, journal = {Materials}, number = {24}, issn = {1996-1944}, doi = {10.3390/ma12244062}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-193897}, pages = {4062}, year = {2019}, abstract = {Radioresistance is an important cause of head and neck cancer therapy failure. Zinc oxide nanoparticles (ZnO-NP) mediate tumor-selective toxic effects. The aim of this study was to evaluate the potential for radiosensitization of ZnO-NP. The dose-dependent cytotoxicity of ZnO-NP\(_{20 nm}\) and ZnO-NP\(_{100 nm}\) was investigated in FaDu and primary fibroblasts (FB) by an MTT assay. The clonogenic survival assay was used to evaluate the effects of ZnO-NP alone and in combination with irradiation on FB and FaDu. A formamidopyrimidine-DNA glycosylase (FPG)-modified single-cell microgel electrophoresis (comet) assay was applied to detect oxidative DNA damage in FB as a function of ZnO-NP and irradiation exposure. A significantly increased cytotoxicity after FaDu exposure to ZnO-NP\(_{20 nm}\) or ZnO-NP\(_{100 nm}\) was observed in a concentration of 10 µg/mL or 1 µg/mL respectively in 30 µg/mL of ZnO-NP\(_{20 nm}\) or 20 µg/mL of ZnO-NP\(_{100 nm}\) in FB. The addition of 1, 5, or 10 µg/mL ZnO-NP\(_{20 nm}\) or ZnO-NP\(_{100 nm}\) significantly reduced the clonogenic survival of FaDu after irradiation. The sub-cytotoxic dosage of ZnO-NP\(_{100 nm}\) increased the oxidative DNA damage compared to the irradiated control. This effect was not significant for ZnO-NP\(_{20 nm}\). ZnO-NP showed radiosensitizing properties in the sub-cytotoxic dosage. At least for the ZnO-NP\(_{100 nm}\), an increased level of oxidative stress is a possible mechanism of the radiosensitizing effect.}, language = {en} } @article{ScherzadMeyerKleinsasseretal.2020, author = {Scherzad, Agmal and Meyer, Till and Kleinsasser, Norbert and Hackenberg, Stephan}, title = {Erratum: Scherzad, A., et al. Molecular mechanisms of zinc oxide nanoparticle-induced genotoxicity short running title: Genotoxicity of ZnO NPs. Materials 2017, 10, 1427}, series = {Materials}, volume = {13}, journal = {Materials}, number = {23}, issn = {1996-1944}, doi = {10.3390/ma13235462}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-219440}, year = {2020}, abstract = {No abstract available}, language = {en} } @article{MoratinIckrathScherzadetal.2021, author = {Moratin, Helena and Ickrath, Pascal and Scherzad, Agmal and Meyer, Till Jasper and Naczenski, Sebastian and Hagen, Rudolf and Hackenberg, Stephan}, title = {Investigation of the immune modulatory potential of zinc oxide nanoparticles in human lymphocytes}, series = {Nanomaterials}, volume = {11}, journal = {Nanomaterials}, number = {3}, issn = {2079-4991}, doi = {10.3390/nano11030629}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234016}, year = {2021}, abstract = {Zinc oxide nanoparticles (ZnO-NP) are commonly used for a variety of applications in everyday life. In addition, due to its versatility, nanotechnology supports promising approaches in the medical sector. NP can act as drug-carriers in the context of targeted chemo- or immunotherapy, and might also exhibit autonomous immune-modulatory characteristics. Knowledge of potential immunosuppressive or stimulating effects of NP is indispensable for the safety of consumers as well as patients. In this study, primary human peripheral blood lymphocytes of 9 donors were treated with different sub-cytotoxic concentrations of ZnO-NP for the duration of 1, 2, or 3 days. Flow cytometry was performed to investigate changes in the activation profile and the proportion of T cell subpopulations. ZnO-NP applied in this study did not induce any significant alterations in the examined markers, indicating their lack of impairment in terms of immune modulation. However, physicochemical characteristics exert a major influence on NP-associated bioactivity. To allow a precise simulation of the complex molecular processes of immune modulation, a physiological model including the different components of an immune response is needed.}, language = {en} }