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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

Oxidative stress dose response assay. Cell suspension cultures treated with QDs and H2DCFDA: (A) 1 nM QDs, (B) 5 nM QDs, (C) 10 nM QDs, (D) 20 nM QDs, (E) 40 nM QDs, (F) 60 nM QDs, (G) 100 nM QDs, (H) 120 nM QDs, (I) 180 nM QDs. Scale bar = 50 μM. (J) graphic representation of mean fluorescence intensity of pictures from cultures subjected to the different treatments. Data representing means from two independent experiments + SD (n = 6 in each experiment), except for the conditions 120 nM and 180 nM which represent one experiment (n = 7). Columns with * indicate a significant difference from the control value with p < 0.001 (ANOVA). Fluorescence intensity in cultures treated with QDs shows a linear behaviour represented by Y = 0,1581x + 9,6342 and R² = 0,9735. The H2DCFDA assay was performed 48 hours after the QD addition.
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Figure 9: Oxidative stress dose response assay. Cell suspension cultures treated with QDs and H2DCFDA: (A) 1 nM QDs, (B) 5 nM QDs, (C) 10 nM QDs, (D) 20 nM QDs, (E) 40 nM QDs, (F) 60 nM QDs, (G) 100 nM QDs, (H) 120 nM QDs, (I) 180 nM QDs. Scale bar = 50 μM. (J) graphic representation of mean fluorescence intensity of pictures from cultures subjected to the different treatments. Data representing means from two independent experiments + SD (n = 6 in each experiment), except for the conditions 120 nM and 180 nM which represent one experiment (n = 7). Columns with * indicate a significant difference from the control value with p < 0.001 (ANOVA). Fluorescence intensity in cultures treated with QDs shows a linear behaviour represented by Y = 0,1581x + 9,6342 and R² = 0,9735. The H2DCFDA assay was performed 48 hours after the QD addition.

Mentions: Since it is clear that the presence of mercaptopropanoic acid-QDs in cell suspension cultures induces an oxidative stress, it is important to clarify if there is a relation between this cell response and the concentration of mercaptopropanoic acid-QDs. Our results showed that fluorescence increased with the increasing concentrations of mercaptopropanoic acid-QDs (Fig. 9a-i).


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)

Oxidative stress dose response assay. Cell suspension cultures treated with QDs and H2DCFDA: (A) 1 nM QDs, (B) 5 nM QDs, (C) 10 nM QDs, (D) 20 nM QDs, (E) 40 nM QDs, (F) 60 nM QDs, (G) 100 nM QDs, (H) 120 nM QDs, (I) 180 nM QDs. Scale bar = 50 μM. (J) graphic representation of mean fluorescence intensity of pictures from cultures subjected to the different treatments. Data representing means from two independent experiments + SD (n = 6 in each experiment), except for the conditions 120 nM and 180 nM which represent one experiment (n = 7). Columns with * indicate a significant difference from the control value with p < 0.001 (ANOVA). Fluorescence intensity in cultures treated with QDs shows a linear behaviour represented by Y = 0,1581x + 9,6342 and R² = 0,9735. The H2DCFDA assay was performed 48 hours after the QD addition.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 9: Oxidative stress dose response assay. Cell suspension cultures treated with QDs and H2DCFDA: (A) 1 nM QDs, (B) 5 nM QDs, (C) 10 nM QDs, (D) 20 nM QDs, (E) 40 nM QDs, (F) 60 nM QDs, (G) 100 nM QDs, (H) 120 nM QDs, (I) 180 nM QDs. Scale bar = 50 μM. (J) graphic representation of mean fluorescence intensity of pictures from cultures subjected to the different treatments. Data representing means from two independent experiments + SD (n = 6 in each experiment), except for the conditions 120 nM and 180 nM which represent one experiment (n = 7). Columns with * indicate a significant difference from the control value with p < 0.001 (ANOVA). Fluorescence intensity in cultures treated with QDs shows a linear behaviour represented by Y = 0,1581x + 9,6342 and R² = 0,9735. The H2DCFDA assay was performed 48 hours after the QD addition.
Mentions: Since it is clear that the presence of mercaptopropanoic acid-QDs in cell suspension cultures induces an oxidative stress, it is important to clarify if there is a relation between this cell response and the concentration of mercaptopropanoic acid-QDs. Our results showed that fluorescence increased with the increasing concentrations of mercaptopropanoic acid-QDs (Fig. 9a-i).

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