CAN STANDARD GENOTOXICITY TESTS BE APPLIED TO NANOPARTICLES?
CAN STANDARD GENOTOXICITY TESTS BE APPLIED TO NANOPARTICLES?
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DOI：
10.1080/15287394.2012.690326
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发表时间：
2012-01-01
影响因子：
2.6
通讯作者：
Dusinska, Maria
中科院分区：
文献类型：
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作者：
Magdolenova, Zuzana;Lorenzo, Yolanda;Dusinska, Maria
进行了实验，以确定两种常见的遗传毒性测试程序，彗星试验和微核（MN）试验，当应用于纳米颗粒（NP）时的有效性。彗星试验用于检测细胞DNA中诱导的链断裂（SB）。如果残留的NP仍然靠近由琼脂糖包埋细胞的裂解产生的几乎裸露的DNA，并且以完整细胞中染色质不发生的方式与该DNA发生反应，则有可能获得假阳性结果。然而，数据显示，如果NP故意以高浓度存在于裂解细胞中，则SB不会随NP范围的变化而变化。只有油酸包覆的fe3o4np才会引起损伤，因为这些颗粒也会在整个细胞中产生等效的改变。彗星试验的一种改进包括用病变特异性核酸内切酶消化DNA，特别是formamidopy嘧啶DNA糖基化酶（FPG），它检测氧化嘌呤。再一次，人们担心在裂解细胞的DNA中存在残留的NP，但这一次是因为如果NP干扰FPG反应，则有假阴性结果的风险。然而，研究发现，在用已知的8-氧鸟嘌呤诱导剂处理之前，用NP孵育细胞并不会导致fpg敏感位点的产量下降。染色体损伤检测与MN测定，这取决于使用细胞松弛素B (CB)，以防止细胞分裂和积累双核细胞。众所周知，黑炭黑也抑制内吞作用，因此可能阻止NP摄取。数据表明，如果将NP与CB一起加入细胞，则诱导的MN较少。因此，为了避免干扰和可能的假阴性结果，有必要在CB之前用NP处理细胞。
Experiments were conducted to determine the validity of two common genotoxicity testing procedures, the comet assay and the micronucleus (MN) test, when applied to nanoparticles (NP). The comet assay is used to detect strand breaks (SB) induced in cellular DNA. There is a possibility of obtaining false positive results, if residual NP remain in proximity to the virtually naked DNA that results from lysis of agarose-embedded cells, and react with this DNA in ways that do not occur with chromatin in intact cells. However, data showed that if NP are deliberately present at high concentration with lysed cells, there is no change in SB with a range of NP. Only oleic acid-coated Fe3O4 NP induced damage, as these particles also produced equivalent alterations in whole cells. A modification of the comet assay incorporates digestion of DNA with lesion-specific endonucleases, notably formamidopyrimidine DNA glycosylase (FPG), which detects oxidized purines. Again there is a concern regarding the presence of residual NP with DNA of lysed cells, but this time because of the risk of false negative results if NP interfere with the FPG reaction. However, it was found that incubation of cells with NP before treatment with a known 8-oxoguanine-inducing agent does not lead to any decrease in the yield of FPG-sensitive sites. Chromosomal damage is detected with the MN assay, which depends on the use of cytochalasin B (CB) to prevent cell division and accumulates binucleate cells. It is known that CB also inhibits endocytosis, and thus might prevent NP uptake. Data demonstrated that if NP are added to cells together with CB, fewer MN are induced. It is therefore necessary to treat cells with NP prior to CB in order to avoid interference and possible false negative results.