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Threshold Dose of Three Types of Quantum Dots (QDs) Induces Oxidative Stress Triggers DNA Damage and Apoptosis in Mouse Fibroblast L929 Cells.

Zhang T, Wang Y, Kong L, Xue Y, Tang M - Int J Environ Res Public Health (2015)

Bottom Line: Also, we compared the toxic effects of QDs with different raw chemical compositions and sizes.The results showed that low concentrations of QDs (≤7 μg/mL) had no obvious effect on cell viability and cell membrane damage, oxidative damage, cell apoptosis or DNA damage.In addition, when comparing the three types of QDs, 2.2 nm CdTe QDs exposure showed a significantly increased proportion of apoptotic cells and significant DNA damage, suggesting that size and composition contribute to the toxic effects of QDs.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China. zhangting@seu.edu.cn.

ABSTRACT
Although it has been reported that fluorescent quantum dots (QDs) have obvious acute toxic effects in vitro, their toxic effects at low doses or threshold doses are still unknown. Therefore, we evaluated the biological histocompatibility and in vitro toxicity of three types of QDs at threshold doses. Also, we compared the toxic effects of QDs with different raw chemical compositions and sizes. The results showed that low concentrations of QDs (≤7 μg/mL) had no obvious effect on cell viability and cell membrane damage, oxidative damage, cell apoptosis or DNA damage. However, QD exposure led to a significant cytotoxicity at higher doses (≥14 μg/mL) and induced abnormal cellular morphology. In addition, when comparing the three types of QDs, 2.2 nm CdTe QDs exposure showed a significantly increased proportion of apoptotic cells and significant DNA damage, suggesting that size and composition contribute to the toxic effects of QDs. Based on these discussions, it was concluded that the concentration (7 μg/mL) may serve as a threshold level for these three types of QDs only in L929 fibroblasts, whereas high concentrations (above 14 μg/mL) may be toxic, resulting in inhibition of proliferation, induction of apoptosis and DNA damage in L929 fibroblasts.

No MeSH data available.


Related in: MedlinePlus

Percentage of hemolysis of RBCs incubated with three types of QDs at different concentrations ranging from 10 to 160 μg/mL for 30 min. Data are the mean ± SD of three separate experiments. Significance was indicated by: #p < 0.05 vs. 2.2 m CdTe QDs.
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ijerph-12-13435-f002: Percentage of hemolysis of RBCs incubated with three types of QDs at different concentrations ranging from 10 to 160 μg/mL for 30 min. Data are the mean ± SD of three separate experiments. Significance was indicated by: #p < 0.05 vs. 2.2 m CdTe QDs.

Mentions: The biological histocompatibilities of the CdTe/CdSe QDs were studied via hemolysis experiments. The release of hemoglobin was used to quantify the membrane-damaging properties of the different size of CdTe/CdSe QDs. Erythrocytes were incubated with five different QDs concentrations in the range of 10~160 μg/mL for 30 min. As shown in the Figure 2, the hemolysis percentage of RBCs increases in a concentration-dependent manner in three types of QDs. When exposed to the dose up to 80 μg/mL, the hemolysis of three types of QDs was slightly increased, and the highest of the hemolysis percentage was 2.2 nm CdTe (5.12%). Under these conditions, 2.2 nm CdSe QDs, 2.2 nm CdTe and 3.5 nm CdTe QDs showed no hemolytic effects up to 160 μg/mL, indicating no detectable disturbance of the red blood cell membranes. However, it is apparent that the hemolysis of 2.2 nm CdTe (5.21%) was significantly different compared with the hemolysis of 3.5 nm CdTe QDs (3.94%), and the difference was significant (p < 0.05). This result demonstrates that the smaller particles have higher hemolytic activity than the larger particles.


Threshold Dose of Three Types of Quantum Dots (QDs) Induces Oxidative Stress Triggers DNA Damage and Apoptosis in Mouse Fibroblast L929 Cells.

Zhang T, Wang Y, Kong L, Xue Y, Tang M - Int J Environ Res Public Health (2015)

Percentage of hemolysis of RBCs incubated with three types of QDs at different concentrations ranging from 10 to 160 μg/mL for 30 min. Data are the mean ± SD of three separate experiments. Significance was indicated by: #p < 0.05 vs. 2.2 m CdTe QDs.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4627041&req=5

ijerph-12-13435-f002: Percentage of hemolysis of RBCs incubated with three types of QDs at different concentrations ranging from 10 to 160 μg/mL for 30 min. Data are the mean ± SD of three separate experiments. Significance was indicated by: #p < 0.05 vs. 2.2 m CdTe QDs.
Mentions: The biological histocompatibilities of the CdTe/CdSe QDs were studied via hemolysis experiments. The release of hemoglobin was used to quantify the membrane-damaging properties of the different size of CdTe/CdSe QDs. Erythrocytes were incubated with five different QDs concentrations in the range of 10~160 μg/mL for 30 min. As shown in the Figure 2, the hemolysis percentage of RBCs increases in a concentration-dependent manner in three types of QDs. When exposed to the dose up to 80 μg/mL, the hemolysis of three types of QDs was slightly increased, and the highest of the hemolysis percentage was 2.2 nm CdTe (5.12%). Under these conditions, 2.2 nm CdSe QDs, 2.2 nm CdTe and 3.5 nm CdTe QDs showed no hemolytic effects up to 160 μg/mL, indicating no detectable disturbance of the red blood cell membranes. However, it is apparent that the hemolysis of 2.2 nm CdTe (5.21%) was significantly different compared with the hemolysis of 3.5 nm CdTe QDs (3.94%), and the difference was significant (p < 0.05). This result demonstrates that the smaller particles have higher hemolytic activity than the larger particles.

Bottom Line: Also, we compared the toxic effects of QDs with different raw chemical compositions and sizes.The results showed that low concentrations of QDs (≤7 μg/mL) had no obvious effect on cell viability and cell membrane damage, oxidative damage, cell apoptosis or DNA damage.In addition, when comparing the three types of QDs, 2.2 nm CdTe QDs exposure showed a significantly increased proportion of apoptotic cells and significant DNA damage, suggesting that size and composition contribute to the toxic effects of QDs.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing 210009, China. zhangting@seu.edu.cn.

ABSTRACT
Although it has been reported that fluorescent quantum dots (QDs) have obvious acute toxic effects in vitro, their toxic effects at low doses or threshold doses are still unknown. Therefore, we evaluated the biological histocompatibility and in vitro toxicity of three types of QDs at threshold doses. Also, we compared the toxic effects of QDs with different raw chemical compositions and sizes. The results showed that low concentrations of QDs (≤7 μg/mL) had no obvious effect on cell viability and cell membrane damage, oxidative damage, cell apoptosis or DNA damage. However, QD exposure led to a significant cytotoxicity at higher doses (≥14 μg/mL) and induced abnormal cellular morphology. In addition, when comparing the three types of QDs, 2.2 nm CdTe QDs exposure showed a significantly increased proportion of apoptotic cells and significant DNA damage, suggesting that size and composition contribute to the toxic effects of QDs. Based on these discussions, it was concluded that the concentration (7 μg/mL) may serve as a threshold level for these three types of QDs only in L929 fibroblasts, whereas high concentrations (above 14 μg/mL) may be toxic, resulting in inhibition of proliferation, induction of apoptosis and DNA damage in L929 fibroblasts.

No MeSH data available.


Related in: MedlinePlus