Abstract:

OBJECTIVE: To compare the genotoxic characteristics of micronucleus cytomic effect of the two differential fluorescence wave lengths CdSeS/ZnS-COOH alloyed quantum dots(QDs). METHODS:Using the cytokinesis block micronucleus cytomic assays as the major method, mouse lymphoma cells (L5178Y) were put under the test doses of 0.062 5, 0.125, 0.25, 0.5 and 0.1 mg/mL, the micronucleus cytomic effect, dose-effect and time-effect relationships were assessed. RESULTS:Compared with the negative control group, the two wavelengths of CdSeS/ZnS-COOH alloyed QDs at 0.062 5 mg/mL could induce the emergence of micronucleus(P<0.05). Both could induce types Ⅰ and Ⅱ micronucleus and nuclear buds effects, but 490 nm alloyed QDs could not induce nucleoplasmic bridge effect, while 540 nm alloyed QDs could. 490 nm alloyed QDs at the lowest dose could induce total micronucleus, typeⅠ micronucleus and nuclear buds, whilst 540 nm alloyed QDs at the lowest dose could induce typeⅠmicronucleus. With the increasing dose other effects emerged. The micronucleus cytomic effect of various groups had a clear dose-response relationship(P<0.05). 490 nm QDs could induce the emergence of nucleoplasmic bridges first after 9 h exposure, while 540 nm QDs induced the increase of total micronucleus and type Ⅱ micronucleus first. As time increased other effects began to develop, and reached their peaks at 27 h, then declined. CONCLUSION:Both QDs could induce micronuclus cytomic effect, but at the same dose their spectrum of effect, dose-effect and time-effect were different, which showed that they possessed different genotoxic characteristics.

Key words: alloyed quantum dots, genotoxicity, micronucleus genomic effect, CdSeS/ZnS-COOH