caa a22 4500 606234284 CHVBK 20210128101236.0 cr unu---uuuuu 210128e20150101xx s 000 0 eng 10.1007/s11010-014-2232-y doi (NATIONALLICENCE)springer-10.1007/s11010-014-2232-y Melanin Nanoparticles (MNPs) provide protection against whole-body ɣ-irradiation in mice via restoration of hematopoietic tissues [Elektronische Daten] [Monira Rageh, Reem EL-Gebaly, H. Abou-Shady, Doaa Amin] During radiotherapy, ionizing irradiation interacts with biological systems to produce free radicals, which attack various cellular components. The hematopoietic system is easily recognized to be radiosensitive and its damage may be severe. Melanin nanoparticles (MNPs) act as free radical scavengers prepared by polymerization of dopamine. In this study, a total of 110 male BALB/C mice were divided into five equal groups. Each group contained 22 mice. Mice of group A did not receive MNPs or irradiation (control group), group B was injected intraperitoneally (i.p.) with 50mg/kg MNPs. Mice of group C and D were exposed to a dose of 7Gy ɣ-irradiation and injected with the same dose of MNPs as in group B either 30min pre- or post-irradiation, and group E was exposed to a dose of 7Gy ɣ-irradiation only. The impact of MNPs on peripheral blood, spleen, and DNA damage induced by irradiation was evaluated by blood count, histopathology of the spleen, and comet assay for the DNA in the bone marrow at 1, 4, 8, and 12days post-irradiation. Results of group E compared with control group (A) showed a significant depression in complete blood count. Additionally, histopathological observation showed the absence of megakaryocytes with delayed time post-irradiation, deposition of eosinophilic protein of their spleen appeared, as well as a remarkable decrease in spleen size was observed. Moreover, ɣ-irradiation-induced DNA damage as can be inferred from a significant increase by about 5-10 folds in all comet parameters (% of DNA, tail length, tail moment, and olive moment) in the DNA of the bone marrow. In contrast, pre-post treatment with MNPs protected hematopoietic tissues against radiation damage, and therefore, enhanced the survival of mice with 40% in groups (C&D) compared with 10% to group (E) till 30days post-irradiation. In conclusion, these results demonstrated that synthetic MNPs provide significant radioprotection to the hematopoietic tissues. Springer Science+Business Media New York, 2014 Melanin nanoparticles nationallicence Radioprotection nationallicence ɤ-irradiation nationallicence DNA damage nationallicence Rageh Monira Department of Biophysics, Faculty of Science, Cairo University, Giza, Egypt aut EL-Gebaly Reem Department of Biophysics, Faculty of Science, Cairo University, Giza, Egypt aut Abou-Shady H. Department of Physics, Faculty of Science, Cairo University, Giza, Egypt aut Amin Doaa Department of Biophysics, Faculty of Science, Cairo University, Giza, Egypt aut Molecular and Cellular Biochemistry Springer US; http://www.springer-ny.com 399/1-2(2015-01-01), 59-69 0300-8177 399:1-2<59 2015 399 11010 https://doi.org/10.1007/s11010-014-2232-y text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s11010-014-2232-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Rageh Monira Department of Biophysics, Faculty of Science, Cairo University, Giza, Egypt aut NATIONALLICENCE 700 1- EL-Gebaly Reem Department of Biophysics, Faculty of Science, Cairo University, Giza, Egypt aut NATIONALLICENCE 700 1- Abou-Shady H. Department of Physics, Faculty of Science, Cairo University, Giza, Egypt aut NATIONALLICENCE 700 1- Amin Doaa Department of Biophysics, Faculty of Science, Cairo University, Giza, Egypt aut NATIONALLICENCE 773 0- Molecular and Cellular Biochemistry Springer US; http://www.springer-ny.com 399/1-2(2015-01-01), 59-69 0300-8177 399:1-2<59 2015 399 11010