Effects of different sizes of cerium oxide nanoparticles on the number and constitute of immune cells in peripheral blood of the mice after X-ray irradiation / 肿瘤研究与临床

ABSTRACT

Objective To investigate the effects of cerium oxide nanoparticles of different sizes on the number and constructions of immune cells in peripheral blood of mice after X-ray irradiation. Methods Mice were randomly divided into 4 groups according to body weight layer and the weight of each mouse was weighed. All mice were divided into 6 groups according to weight from high to low, and there were 4 mice in each group. Then 1 mouse was randomly taken from each group to form the control group. Model group, 5 nm and 25 nm cerium oxide nanoparticles groups were formed in turn. There were 6 mice in each group. The mice in model group and cerium oxide nanoparticles administration groups were irradiated once with 3 Gy of X-rays. The mice in cerium oxide nanoparticles groups began to be intraperitoneally administrated once a day with 10 μg 5 nm or 25 nm cerium oxide nanoparticles per kilogram body weight on the 4th day before irradiation and once every other 2 days after irradiation. The mice in the control group and model group were intraperitoneally administrated with 0.9 % saline. The mice were killed on the 10th days after irradiation. White cells count (WBC) and classification in peripheral blood were detected by using automatic globulimeter, and lymphocyte subsets were analyzed by using flow cytometry. Results Compared with the control group, the number of WBC, neutrophil granulocytes, monocytes, lymphocytes, total T lymphocytes, CD4+and CD8+T lymphocytes and the percentages in the model group were decreased (all P＜0.05), and percentages of the lymphocytes, B cells and NK cells and ratio of CD4 to CD8 were increased in model group (all P＜ 0.05). Compared with the model group, the above parameters except percentages of T lymphocytes, CD4+and CD8+T lymphocytes were improved in mice of 5 nm cerium oxide nanoparticle group (all P ＜0.05). Compared with the control group, the number of WBC and lymphocytes were decreased in the 5 nm cerium oxide nanoparticle group (P＜0.05), and there were no significances in other parameters compared with the control group (all P ＞0.05). Compared with the control group, the number of WBC and lymphocytes, the number and percentages of T lymphocytes, CD4+and CD8+T lymphocytes and the percentages were decreased (all P＜ 0.05), and percentage of NK cells and ratio of CD4 to CD8 were significantly increased in 25 nm cerium oxide nanoparticles group (all P＜ 0.05). The number of lymphocytes and CD8+T lymphocytes in 25 nm cerium oxide nanoparticles group was lower than that in 5 nm cerium oxide nanoparticles group (all P ＜ 0.05). Conclusions The effects of cerium oxide nanoparticles of different sizes on the immune cells of mice after X-ray irradiation are different, and 5 nm cerium oxide nanoparticle is superior to 25 nm cerium oxide nanoparticle.