乙二胺为核心的PAMAM树枝状聚合物（5.0代）纳米材料溶液的遗传毒性研究

摘要

OBJECTIVE:To study the genotoxicity of PAMAM dendrimer (ethylenediamine core) generation 5.0 solution.METHODS:In the plate incorporation test ofSalmonella typhimurium,the average colony number of spontaneous revertants of TA97,TA98,TA100,TA102,TA1535 were set at 5 concentrations:3 985,797,139.4, 31.88 and6.376µg per plate. In the cytokinesis-block micronucleus cytome(CBMN Cyt) assay,the final concentration 0.625,1.25,2.5,5,10µg/mL of PAMAM dendrimer (ethylenediamine core) generation 5.0 wasadded to L5178Y cells,then assessed the micronucleus cytome effect,dose-effect and time-effect relationships.RESULTS: The colony number of revertants for the materials tested did not obviously increase,compared with that of spontaneous revertants. The result of Ames test for the subject was negative. In the CBMN Cyt assay,the frequency of nuclear buds increased at concentration of 1.25µg/mL.The formation of total,type Ⅰ andtypeⅡ micronuclei as well as nuclear-cytoplasmic bridges were oberservedat andabove concentration of 2.5µg/mL. At of 5µg/mL,the time-effect results indicated that the number of total,type Ⅰ amdtype Ⅱ micronuclei and nuclear buds increased at 9 h,while the nucleoplasmic bridges started to increase at 18h. The indexes of total,type Ⅰandtype Ⅱ micronuclei,nucleoplasmic bridges and nuclear buds reached their peak at 27 h.CONCLUSION:The PAMAM dendrimer (ethylenediamine core) generation 5.0 solution showed no potential mutagenicity. While could cause four kinds of micronucleus cytome effects with clear dose-effect and time-effect in L5178Y cells. From the dose and time point of view,nuclear bud was the most sensitive index.%目的：研究乙二胺为核心的PAMAM树枝状聚合物(5.0代)纳米材料溶液的遗传毒性。方法：采用Ames试验平板掺入法，设3985、797、139.4、31.88和6.376µg/皿的5个乙二胺为核心的PAMAM树枝状聚合物(5.0代)溶液浓度组，在加与不加S9混合液的条件下观察回变菌落数。同时采用L5178Y细胞胞质分裂阻滞微核细胞组学试验，给予受试细胞终浓度分别为0.625、1.25、2.5、5、10µg/mL的受试物，观察其微核组效应、剂量-效应和时间-效应关系。结果：受试物溶液各剂量组均未引起测试菌株回变菌落数明显增加，Ames试验结果为阴性。胞质分裂阻滞微核细胞组学试验中，与阴性对照组比较，1.25μg/mL的受试物即可诱导受试细胞出现核芽(P<0.01)；2.5µg/mL及以上剂量可进一步诱使细胞出现总微核、Ⅰ型微核、Ⅱ型微核和核质桥效应(P<0.01)，且存在明显的剂量-效应关系(除核质桥外，r值均>0.5，P均<0.05)。与阴性对照组比较，在5μg/mL剂量下，乙二胺为核心的PAMAM树枝状聚合物(5.0代)溶液在9 h时即可诱导受试细胞的总微核、Ⅰ型微核、Ⅱ型微核和核芽增加(P<0.01)；在18 h时出现核质桥数增加(P<0.01)，各项指标在27 h达到峰值。结论：乙二胺为核心的PAMAM树枝状聚合物(5.0代)溶液对鼠伤寒沙门氏菌无致基因突变作用；对L5178Y细胞可诱导4类微核组效应，并有明显的剂量-效应和时间-效应关系；从剂量和时间来看，以核芽效应最为敏感。