Limits...
The cadmium-mercaptoacetic acid complex contributes to the genotoxicity of mercaptoacetic acid-coated CdSe-core quantum dots.

Tang W, Fan J, He Y, Huang B, Liu H, Pang D, Xie Z - Int J Nanomedicine (2012)

Bottom Line: Quantum dots (QDs) have many potential clinical and biological applications because of their advantages over traditional fluorescent dyes.However, the genotoxicity potential of QDs still remains unclear.The electrospray ionization mass spectrometry data suggested that the observed genotoxicity might be correlated with the cadmium-mercaptoacetic acid complex (Cd-MAA) that is formed in the solution of MAA-QDs.

View Article: PubMed Central - PubMed

Affiliation: College of Life Sciences, Wuhan University, Wuhan, People's Republic of China.

ABSTRACT
Quantum dots (QDs) have many potential clinical and biological applications because of their advantages over traditional fluorescent dyes. However, the genotoxicity potential of QDs still remains unclear. In this paper, a plasmid-based system was designed to explore the genotoxic mechanism of QDs by detecting changes in DNA configuration and biological activities. The direct chemicobiological interactions between DNA and mercaptoacetic acid-coated CdSecore QDs (MAA-QDs) were investigated. After incubation with different concentrations of MAA-QDs (0.043, 0.13, 0.4, 1.2, and 3.6 μmol/L) in the dark, the DNA conversion of the covalently closed circular (CCC) DNA to the open circular (OC) DNA was significantly enhanced (from 13.9% ± 2.2% to 59.9% ± 12.8%) while the residual transformation activity of plasmid DNA was greatly decreased (from 80.7% ± 12.8% to 13.6% ± 0.8%), which indicated that the damages to the DNA structure and biological activities induced by MAA-QDs were concentration-dependent. The electrospray ionization mass spectrometry data suggested that the observed genotoxicity might be correlated with the cadmium-mercaptoacetic acid complex (Cd-MAA) that is formed in the solution of MAA-QDs. Circular dichroism spectroscopy and transformation assay results indicated that the Cd-MAA complex might interact with DNA through the groove-binding mode and prefer binding to DNA fragments with high adenine and thymine content. Furthermore, the plasmid transformation assay could be used as an effective method to evaluate the genotoxicities of nanoparticles.

Show MeSH

Related in: MedlinePlus

Effects of different nanoparticles on the transformablities of plasmid DNA.Notes: DNA qualities of plasmids pUC18 incubated with nano-TiO2 (1.5 mg/mL), fullerenes (1.5 mg/mL), MAA–QDs (3.6 μmol/L) and OPA-QDs (3 μmol/L) for 2 hours at 4°C in the dark were tested by transformation with Escherichia coli strain DH5α. There is no significant difference between the incubated and non-incubated plasmids in transformation activity when plasmids were incubated with nano-TiO2, fullerenes, and OPA-QDs (P > 0.05), respectively.Abbreviations: MAA-QDs, mercaptoacetic acid-coated quantum dots; OPA-QDs, octylamine-modified polyacrylic acid-coated quantum dots.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3368512&req=5

f2-ijn-7-2631: Effects of different nanoparticles on the transformablities of plasmid DNA.Notes: DNA qualities of plasmids pUC18 incubated with nano-TiO2 (1.5 mg/mL), fullerenes (1.5 mg/mL), MAA–QDs (3.6 μmol/L) and OPA-QDs (3 μmol/L) for 2 hours at 4°C in the dark were tested by transformation with Escherichia coli strain DH5α. There is no significant difference between the incubated and non-incubated plasmids in transformation activity when plasmids were incubated with nano-TiO2, fullerenes, and OPA-QDs (P > 0.05), respectively.Abbreviations: MAA-QDs, mercaptoacetic acid-coated quantum dots; OPA-QDs, octylamine-modified polyacrylic acid-coated quantum dots.

Mentions: Furthermore, biological effects of nano-TiO2, fullerenes, and octylamine-modified polyacrylic acid-coated CdSe/ZnS QDs (OPA-QDs) were also investigated using the transformation assay. DNA qualities of plasmids pUC18 incubated with nano-TiO2 (1.5 mg/mL), fullerenes (1.5 mg/mL) and OPA-QDs (3 μmol/L) for 2 hours at 4°C in the dark were tested by transformation with E. coli strain DH5α. The results demonstrated that there is no significant difference between the incubated and non-incubated plasmids in transformation activity (P > 0.05, Figure 2). Hence, in the present study, despite the different mechanisms of DNA damage that are caused by nanoparticles, a quantitative analysis method was well established and the effects of damage from most nanoparticles on DNA could be evaluated in the plasmid-based noncellular system.


The cadmium-mercaptoacetic acid complex contributes to the genotoxicity of mercaptoacetic acid-coated CdSe-core quantum dots.

Tang W, Fan J, He Y, Huang B, Liu H, Pang D, Xie Z - Int J Nanomedicine (2012)

Effects of different nanoparticles on the transformablities of plasmid DNA.Notes: DNA qualities of plasmids pUC18 incubated with nano-TiO2 (1.5 mg/mL), fullerenes (1.5 mg/mL), MAA–QDs (3.6 μmol/L) and OPA-QDs (3 μmol/L) for 2 hours at 4°C in the dark were tested by transformation with Escherichia coli strain DH5α. There is no significant difference between the incubated and non-incubated plasmids in transformation activity when plasmids were incubated with nano-TiO2, fullerenes, and OPA-QDs (P > 0.05), respectively.Abbreviations: MAA-QDs, mercaptoacetic acid-coated quantum dots; OPA-QDs, octylamine-modified polyacrylic acid-coated quantum dots.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3368512&req=5

f2-ijn-7-2631: Effects of different nanoparticles on the transformablities of plasmid DNA.Notes: DNA qualities of plasmids pUC18 incubated with nano-TiO2 (1.5 mg/mL), fullerenes (1.5 mg/mL), MAA–QDs (3.6 μmol/L) and OPA-QDs (3 μmol/L) for 2 hours at 4°C in the dark were tested by transformation with Escherichia coli strain DH5α. There is no significant difference between the incubated and non-incubated plasmids in transformation activity when plasmids were incubated with nano-TiO2, fullerenes, and OPA-QDs (P > 0.05), respectively.Abbreviations: MAA-QDs, mercaptoacetic acid-coated quantum dots; OPA-QDs, octylamine-modified polyacrylic acid-coated quantum dots.
Mentions: Furthermore, biological effects of nano-TiO2, fullerenes, and octylamine-modified polyacrylic acid-coated CdSe/ZnS QDs (OPA-QDs) were also investigated using the transformation assay. DNA qualities of plasmids pUC18 incubated with nano-TiO2 (1.5 mg/mL), fullerenes (1.5 mg/mL) and OPA-QDs (3 μmol/L) for 2 hours at 4°C in the dark were tested by transformation with E. coli strain DH5α. The results demonstrated that there is no significant difference between the incubated and non-incubated plasmids in transformation activity (P > 0.05, Figure 2). Hence, in the present study, despite the different mechanisms of DNA damage that are caused by nanoparticles, a quantitative analysis method was well established and the effects of damage from most nanoparticles on DNA could be evaluated in the plasmid-based noncellular system.

Bottom Line: Quantum dots (QDs) have many potential clinical and biological applications because of their advantages over traditional fluorescent dyes.However, the genotoxicity potential of QDs still remains unclear.The electrospray ionization mass spectrometry data suggested that the observed genotoxicity might be correlated with the cadmium-mercaptoacetic acid complex (Cd-MAA) that is formed in the solution of MAA-QDs.

View Article: PubMed Central - PubMed

Affiliation: College of Life Sciences, Wuhan University, Wuhan, People's Republic of China.

ABSTRACT
Quantum dots (QDs) have many potential clinical and biological applications because of their advantages over traditional fluorescent dyes. However, the genotoxicity potential of QDs still remains unclear. In this paper, a plasmid-based system was designed to explore the genotoxic mechanism of QDs by detecting changes in DNA configuration and biological activities. The direct chemicobiological interactions between DNA and mercaptoacetic acid-coated CdSecore QDs (MAA-QDs) were investigated. After incubation with different concentrations of MAA-QDs (0.043, 0.13, 0.4, 1.2, and 3.6 μmol/L) in the dark, the DNA conversion of the covalently closed circular (CCC) DNA to the open circular (OC) DNA was significantly enhanced (from 13.9% ± 2.2% to 59.9% ± 12.8%) while the residual transformation activity of plasmid DNA was greatly decreased (from 80.7% ± 12.8% to 13.6% ± 0.8%), which indicated that the damages to the DNA structure and biological activities induced by MAA-QDs were concentration-dependent. The electrospray ionization mass spectrometry data suggested that the observed genotoxicity might be correlated with the cadmium-mercaptoacetic acid complex (Cd-MAA) that is formed in the solution of MAA-QDs. Circular dichroism spectroscopy and transformation assay results indicated that the Cd-MAA complex might interact with DNA through the groove-binding mode and prefer binding to DNA fragments with high adenine and thymine content. Furthermore, the plasmid transformation assay could be used as an effective method to evaluate the genotoxicities of nanoparticles.

Show MeSH
Related in: MedlinePlus