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The impact of CdSe/ZnS Quantum Dots in cells of Medicago sativa in suspension culture.

Santos AR, Miguel AS, Tomaz L, Malhó R, Maycock C, Vaz Patto MC, Fevereiro P, Oliva A - J Nanobiotechnology (2010)

Bottom Line: Cell growth was significantly reduced when 100 mM of mercaptopropanoic acid -QDs was added during the exponential growth phase, with less than 50% of the cells viable 72 hours after mercaptopropanoic acid -QDs addition.As part of the cellular response to internalization, Medicago sativa cells were found to increase the production of Reactive Oxygen Species (ROS) in a dose and time dependent manner.Our results showed that the extent of mercaptopropanoic acid coated CdSe/ZnS QDs cytotoxicity in plant cells is dependent upon a number of factors including QDs properties, dose and the environmental conditions of administration and that, for Medicago sativa cells, a safe range of 1-5 nM should not be exceeded for biological applications.

View Article: PubMed Central - HTML - PubMed

Affiliation: Biomolecular Diagnostics Laboratory, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal. raquelsantos@itqb.unl.pt.

ABSTRACT

Background: Nanotechnology has the potential to provide agriculture with new tools that may be used in the rapid detection and molecular treatment of diseases and enhancement of plant ability to absorb nutrients, among others. Data on nanoparticle toxicity in plants is largely heterogeneous with a diversity of physicochemical parameters reported, which difficult generalizations. Here a cell biology approach was used to evaluate the impact of Quantum Dots (QDs) nanocrystals on plant cells, including their effect on cell growth, cell viability, oxidative stress and ROS accumulation, besides their cytomobility.

Results: A plant cell suspension culture of Medicago sativa was settled for the assessment of the impact of the addition of mercaptopropanoic acid coated CdSe/ZnS QDs. Cell growth was significantly reduced when 100 mM of mercaptopropanoic acid -QDs was added during the exponential growth phase, with less than 50% of the cells viable 72 hours after mercaptopropanoic acid -QDs addition. They were up taken by Medicago sativa cells and accumulated in the cytoplasm and nucleus as revealed by optical thin confocal imaging. As part of the cellular response to internalization, Medicago sativa cells were found to increase the production of Reactive Oxygen Species (ROS) in a dose and time dependent manner. Using the fluorescent dye H2DCFDA it was observable that mercaptopropanoic acid-QDs concentrations between 5-180 nM led to a progressive and linear increase of ROS accumulation.

Conclusions: Our results showed that the extent of mercaptopropanoic acid coated CdSe/ZnS QDs cytotoxicity in plant cells is dependent upon a number of factors including QDs properties, dose and the environmental conditions of administration and that, for Medicago sativa cells, a safe range of 1-5 nM should not be exceeded for biological applications.

No MeSH data available.


Related in: MedlinePlus

General oxidative stress assay in cell suspension cultures. (A) Treated with H2DCFDA showing a basal level of fluorescence. (B) Treated 20 minutes at 45°C and H2DCFDA exhibiting a fluorescence increase due to an oxidative stress. (C) Treated with 100 nM QDs and H2DCFDA. (D) Treated with 100 nM QDs for 48 hours and H2DCFDA and (D) treated with 100 nM QDs for 72 hours and H2DCFDA. Scale bar = 50 μM. (F) graphic representation of mean fluorescence intensity in A-E. Black bars represent the mean of pictures from control cultures (cells + H2DCFDA) and grey bars the QD treated cultures in the three exposure times performed. Data represent mean from one experiment (n = 6) + SD. Columns with * indicate a significant difference from the control value with p < 0.001 (ANOVA).
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Figure 8: General oxidative stress assay in cell suspension cultures. (A) Treated with H2DCFDA showing a basal level of fluorescence. (B) Treated 20 minutes at 45°C and H2DCFDA exhibiting a fluorescence increase due to an oxidative stress. (C) Treated with 100 nM QDs and H2DCFDA. (D) Treated with 100 nM QDs for 48 hours and H2DCFDA and (D) treated with 100 nM QDs for 72 hours and H2DCFDA. Scale bar = 50 μM. (F) graphic representation of mean fluorescence intensity in A-E. Black bars represent the mean of pictures from control cultures (cells + H2DCFDA) and grey bars the QD treated cultures in the three exposure times performed. Data represent mean from one experiment (n = 6) + SD. Columns with * indicate a significant difference from the control value with p < 0.001 (ANOVA).

Mentions: When treated with H2DCFDA, control cells showed a basal-level fluorescent signal (Fig. 8a) that accumulated uniformly in the cytoplasm. This has been also reported in tobacco cells by Ashtamker et al. [29]. In the heat treated (45°C/20 min) cell suspension cultures, the DCF signal was significantly increased (Fig. 8b) showing a response in terms of ROS accumulation, also observed in the mercaptopropanoic acid-QDs treated cell suspension cultures (Fig. 8c). These results confirmed the induction of an oxidative stress in cell suspension cultures treated with 100 nM of mercaptopropanoic acid-QDs during 1.5 hours.


The impact of CdSe/ZnS Quantum Dots in cells of Medicago sativa in suspension culture.

Santos AR, Miguel AS, Tomaz L, Malhó R, Maycock C, Vaz Patto MC, Fevereiro P, Oliva A - J Nanobiotechnology (2010)

General oxidative stress assay in cell suspension cultures. (A) Treated with H2DCFDA showing a basal level of fluorescence. (B) Treated 20 minutes at 45°C and H2DCFDA exhibiting a fluorescence increase due to an oxidative stress. (C) Treated with 100 nM QDs and H2DCFDA. (D) Treated with 100 nM QDs for 48 hours and H2DCFDA and (D) treated with 100 nM QDs for 72 hours and H2DCFDA. Scale bar = 50 μM. (F) graphic representation of mean fluorescence intensity in A-E. Black bars represent the mean of pictures from control cultures (cells + H2DCFDA) and grey bars the QD treated cultures in the three exposure times performed. Data represent mean from one experiment (n = 6) + SD. Columns with * indicate a significant difference from the control value with p < 0.001 (ANOVA).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2958997&req=5

Figure 8: General oxidative stress assay in cell suspension cultures. (A) Treated with H2DCFDA showing a basal level of fluorescence. (B) Treated 20 minutes at 45°C and H2DCFDA exhibiting a fluorescence increase due to an oxidative stress. (C) Treated with 100 nM QDs and H2DCFDA. (D) Treated with 100 nM QDs for 48 hours and H2DCFDA and (D) treated with 100 nM QDs for 72 hours and H2DCFDA. Scale bar = 50 μM. (F) graphic representation of mean fluorescence intensity in A-E. Black bars represent the mean of pictures from control cultures (cells + H2DCFDA) and grey bars the QD treated cultures in the three exposure times performed. Data represent mean from one experiment (n = 6) + SD. Columns with * indicate a significant difference from the control value with p < 0.001 (ANOVA).
Mentions: When treated with H2DCFDA, control cells showed a basal-level fluorescent signal (Fig. 8a) that accumulated uniformly in the cytoplasm. This has been also reported in tobacco cells by Ashtamker et al. [29]. In the heat treated (45°C/20 min) cell suspension cultures, the DCF signal was significantly increased (Fig. 8b) showing a response in terms of ROS accumulation, also observed in the mercaptopropanoic acid-QDs treated cell suspension cultures (Fig. 8c). These results confirmed the induction of an oxidative stress in cell suspension cultures treated with 100 nM of mercaptopropanoic acid-QDs during 1.5 hours.

Bottom Line: Cell growth was significantly reduced when 100 mM of mercaptopropanoic acid -QDs was added during the exponential growth phase, with less than 50% of the cells viable 72 hours after mercaptopropanoic acid -QDs addition.As part of the cellular response to internalization, Medicago sativa cells were found to increase the production of Reactive Oxygen Species (ROS) in a dose and time dependent manner.Our results showed that the extent of mercaptopropanoic acid coated CdSe/ZnS QDs cytotoxicity in plant cells is dependent upon a number of factors including QDs properties, dose and the environmental conditions of administration and that, for Medicago sativa cells, a safe range of 1-5 nM should not be exceeded for biological applications.

View Article: PubMed Central - HTML - PubMed

Affiliation: Biomolecular Diagnostics Laboratory, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Apartado 127, 2781-901 Oeiras, Portugal. raquelsantos@itqb.unl.pt.

ABSTRACT

Background: Nanotechnology has the potential to provide agriculture with new tools that may be used in the rapid detection and molecular treatment of diseases and enhancement of plant ability to absorb nutrients, among others. Data on nanoparticle toxicity in plants is largely heterogeneous with a diversity of physicochemical parameters reported, which difficult generalizations. Here a cell biology approach was used to evaluate the impact of Quantum Dots (QDs) nanocrystals on plant cells, including their effect on cell growth, cell viability, oxidative stress and ROS accumulation, besides their cytomobility.

Results: A plant cell suspension culture of Medicago sativa was settled for the assessment of the impact of the addition of mercaptopropanoic acid coated CdSe/ZnS QDs. Cell growth was significantly reduced when 100 mM of mercaptopropanoic acid -QDs was added during the exponential growth phase, with less than 50% of the cells viable 72 hours after mercaptopropanoic acid -QDs addition. They were up taken by Medicago sativa cells and accumulated in the cytoplasm and nucleus as revealed by optical thin confocal imaging. As part of the cellular response to internalization, Medicago sativa cells were found to increase the production of Reactive Oxygen Species (ROS) in a dose and time dependent manner. Using the fluorescent dye H2DCFDA it was observable that mercaptopropanoic acid-QDs concentrations between 5-180 nM led to a progressive and linear increase of ROS accumulation.

Conclusions: Our results showed that the extent of mercaptopropanoic acid coated CdSe/ZnS QDs cytotoxicity in plant cells is dependent upon a number of factors including QDs properties, dose and the environmental conditions of administration and that, for Medicago sativa cells, a safe range of 1-5 nM should not be exceeded for biological applications.

No MeSH data available.


Related in: MedlinePlus