Two Kinds Of Rare Earth Nano Antibacterial Material Safety Animal Testing Research

The effect of two kinds of rare earth nano materials on immune function and germ plasm of the tested animals, from the respect of immunology and genetic toxicity, was researched. The pathological analysis of the some organs was done and finally the possibly existing mechanism was discussed primarily so as to provide some references for the study of safety of the nano materials.First of all, according to the assessing method stipulated in hygiene toxicology to decide the toxicity of foreign matter on animals, combined with the actual application environment of rare earth nano anti-bacterial materials and the research fruits that have already existed, the experimental program and research clue was then confirmed. During the process of study, the chronic toxicity test was done, in which three different contamination methods were used, including skin smearing, oral feeding and injecting (including muscle injecting and vein injecting). The level of immunity (humoral and cellular immunity) of the body was detected respectively at two different time after contamination and the pathological analysis was carried out on the some organs, such as skin, stomach, liver and marrow.Secondly, from the respect of humoral immunology, the level of circulating immune complex (CIC) through PEG experiment and the amount of complement (CH50) in blood serum were detected. The former test results revealed that the level of CIC was raised, differing significantly from the control group. And till the 73rd day after contamination, the amount of CIC didn't recover to the normal level. Excessive CIC caused restrain to the immunity of organism and the deposition of excessive CIC was a important factor to make related target organs damaged; the latter test result showed that the total amount of complement in blood serum was very different from the control group. Meanwhile, from the aspect of cell immunology and genetic toxicity, five medical experiments were carried out, including the determination of T lymphocyte subgroups, erythrocyte fragility, swelling ratio of huge phagocytes, and the experiments of chromosome aberration and the micronucleus analysis in marrow cells. The tests results were as follows, first, the determination of T lymphocyte subgroups demonstrated that the proportion of CD3+ cells (equivalent to the total T lymphocytes), CD4+ cells (equivalent to the auxiliary T lymphocytes) and the ratio of CD4+ cells to CD8+ cells (equivalent to the restraining T lymphocytes) lowered significantly, while the proportion of CD8+ cells ascended, which caused the imbalance of immunologic function of the cells and the disorder of immunoregulation. Second, in erythrocyte fragility experiment, the rare earth nan6 anti-bacterial materials brought great damage to the membrane of erythrocyte (except the skin-contacting group) and made the hemolytic fragility of erythrocytes increase distinctively, which indicated that the rare earth nano materials were of some physiological toxicity to some degree. Third, through swelling experiment of huge phagocytes, it was found that the swelling proportion of huge phagocytes in peritoneal cavity decreased to a lower level compared to the control group, which means that the swelling activity of huge phagocytes lowered and the immunological function attenuated. Fourth, except the skin-contacting group, the rate of micronucleuses of...