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In vitro studies of the toxic effects of silver nanoparticles on HeLa and U937 cells.

Kaba SI, Egorova EM - Nanotechnol Sci Appl (2015)

Bottom Line: It was found that Ag NPs had high toxicity toward both cell types.The minimal concentrations where a toxicity effect was registered (toxicity thresholds) lied in the range 0.5-2.0 μg Ag/mL.It was shown that aerosol-OT had no effect on the viability on HeLa cells, but was moderately toxic toward U937, though less dangerous for these cells than Ag NPs.

View Article: PubMed Central - PubMed

Affiliation: Institute of General Pathology and Pathophysiology, Moscow, Russia.

ABSTRACT
In the last decade, much attention has been paid to studies of the effect of silver nanoparticles (Ag NPs) on tumor cells. Apart from elucidation of the mechanism of NPs' interaction with mammalian cells, these studies are aimed at discovering new effective antitumor drugs. In this work, we report about the toxic effects of Ag NPs observed on two types of tumor cells: HeLa (adhesive cells) and U937 (suspension cells). The Ag NPs were obtained by an original method of biochemical synthesis. Particle size was 13.2±4.72 nm, and zeta potential was -61.9±3.2 mV. The toxicity of Ag NPs in the concentration range 0.5-8.0 μg Ag/mL was determined by means of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and cytofluorometry after 4 and 24 hours' incubation. It was found that Ag NPs had high toxicity toward both cell types. The minimal concentrations where a toxicity effect was registered (toxicity thresholds) lied in the range 0.5-2.0 μg Ag/mL. In parallel with the Ag NP solution, cells were incubated with water solutions of the NP stabilizer (aerosol-OT) and Ag(+) ions (as silver nitrate). It was shown that aerosol-OT had no effect on the viability on HeLa cells, but was moderately toxic toward U937, though less dangerous for these cells than Ag NPs. With Ag(+) ions, for HeLa no toxic effect was observed, while for U937 they were as toxic as the Ag NPs. The data obtained indicate that Ag NPs as used in this study may prove to be useful for the creation of medicines for cancer therapy.

No MeSH data available.


Related in: MedlinePlus

Particle-size distribution in phosphate-buffered saline after incubation with Ag NPs, measured by PCS.Notes: Results are obtained with 4 μg/mL of Ag NPs after 1 (A) and 2 hours’ incubation (B), and with 8 μg/mL of Ag NPs after 1 (C) and 2 hours’ incubation (D). Sizes are given at the peak maxima. Pure PBS was used as control (no particles detected).Abbreviations: Ag NPs, silver nanoparticles; PCS, photon correlation spectroscopy; PBS, phosphate-buffered saline.
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f5-nsa-8-019: Particle-size distribution in phosphate-buffered saline after incubation with Ag NPs, measured by PCS.Notes: Results are obtained with 4 μg/mL of Ag NPs after 1 (A) and 2 hours’ incubation (B), and with 8 μg/mL of Ag NPs after 1 (C) and 2 hours’ incubation (D). Sizes are given at the peak maxima. Pure PBS was used as control (no particles detected).Abbreviations: Ag NPs, silver nanoparticles; PCS, photon correlation spectroscopy; PBS, phosphate-buffered saline.

Mentions: A typical result is shown in Figure 5. After 1 hours’ incubation with 4 μg/mL Ag NPs (Figure 5A), the bimodal size distribution was found, with one peak of low intensity (at 60–100 nm) and one peak of high intensity (at 670–720 nm); this distribution underwent practically no changes in the subsequent 1 or more hours of incubation (Figure 5B). A similar picture was observed with 8 μg/mL Ag NPs (Figure 5C and D), but here both peaks shifted to the bigger sizes, with the low-intensity peak at 150–170 nm and the high-intensity peak at 1,500–1,900 nm. Since 1) mono- and bivalent cation concentrations in PBS were the same as in the cell-culture medium and 2) there were no other components in PBS capable of aggregation to the sizes observed except for Ag NPs, one can conclude that aggregation of Ag NPs (and the corresponding decrease in their toxicity) may take place at high Ag NP concentrations in cell culture. Formation of the Ag NP aggregates in cell-culture media with sizes in similar range has also been noted by other authors.44,45 This is most likely provoked by NP association due to cation adsorption on their negative surface groups.


In vitro studies of the toxic effects of silver nanoparticles on HeLa and U937 cells.

Kaba SI, Egorova EM - Nanotechnol Sci Appl (2015)

Particle-size distribution in phosphate-buffered saline after incubation with Ag NPs, measured by PCS.Notes: Results are obtained with 4 μg/mL of Ag NPs after 1 (A) and 2 hours’ incubation (B), and with 8 μg/mL of Ag NPs after 1 (C) and 2 hours’ incubation (D). Sizes are given at the peak maxima. Pure PBS was used as control (no particles detected).Abbreviations: Ag NPs, silver nanoparticles; PCS, photon correlation spectroscopy; PBS, phosphate-buffered saline.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4356696&req=5

f5-nsa-8-019: Particle-size distribution in phosphate-buffered saline after incubation with Ag NPs, measured by PCS.Notes: Results are obtained with 4 μg/mL of Ag NPs after 1 (A) and 2 hours’ incubation (B), and with 8 μg/mL of Ag NPs after 1 (C) and 2 hours’ incubation (D). Sizes are given at the peak maxima. Pure PBS was used as control (no particles detected).Abbreviations: Ag NPs, silver nanoparticles; PCS, photon correlation spectroscopy; PBS, phosphate-buffered saline.
Mentions: A typical result is shown in Figure 5. After 1 hours’ incubation with 4 μg/mL Ag NPs (Figure 5A), the bimodal size distribution was found, with one peak of low intensity (at 60–100 nm) and one peak of high intensity (at 670–720 nm); this distribution underwent practically no changes in the subsequent 1 or more hours of incubation (Figure 5B). A similar picture was observed with 8 μg/mL Ag NPs (Figure 5C and D), but here both peaks shifted to the bigger sizes, with the low-intensity peak at 150–170 nm and the high-intensity peak at 1,500–1,900 nm. Since 1) mono- and bivalent cation concentrations in PBS were the same as in the cell-culture medium and 2) there were no other components in PBS capable of aggregation to the sizes observed except for Ag NPs, one can conclude that aggregation of Ag NPs (and the corresponding decrease in their toxicity) may take place at high Ag NP concentrations in cell culture. Formation of the Ag NP aggregates in cell-culture media with sizes in similar range has also been noted by other authors.44,45 This is most likely provoked by NP association due to cation adsorption on their negative surface groups.

Bottom Line: It was found that Ag NPs had high toxicity toward both cell types.The minimal concentrations where a toxicity effect was registered (toxicity thresholds) lied in the range 0.5-2.0 μg Ag/mL.It was shown that aerosol-OT had no effect on the viability on HeLa cells, but was moderately toxic toward U937, though less dangerous for these cells than Ag NPs.

View Article: PubMed Central - PubMed

Affiliation: Institute of General Pathology and Pathophysiology, Moscow, Russia.

ABSTRACT
In the last decade, much attention has been paid to studies of the effect of silver nanoparticles (Ag NPs) on tumor cells. Apart from elucidation of the mechanism of NPs' interaction with mammalian cells, these studies are aimed at discovering new effective antitumor drugs. In this work, we report about the toxic effects of Ag NPs observed on two types of tumor cells: HeLa (adhesive cells) and U937 (suspension cells). The Ag NPs were obtained by an original method of biochemical synthesis. Particle size was 13.2±4.72 nm, and zeta potential was -61.9±3.2 mV. The toxicity of Ag NPs in the concentration range 0.5-8.0 μg Ag/mL was determined by means of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and cytofluorometry after 4 and 24 hours' incubation. It was found that Ag NPs had high toxicity toward both cell types. The minimal concentrations where a toxicity effect was registered (toxicity thresholds) lied in the range 0.5-2.0 μg Ag/mL. In parallel with the Ag NP solution, cells were incubated with water solutions of the NP stabilizer (aerosol-OT) and Ag(+) ions (as silver nitrate). It was shown that aerosol-OT had no effect on the viability on HeLa cells, but was moderately toxic toward U937, though less dangerous for these cells than Ag NPs. With Ag(+) ions, for HeLa no toxic effect was observed, while for U937 they were as toxic as the Ag NPs. The data obtained indicate that Ag NPs as used in this study may prove to be useful for the creation of medicines for cancer therapy.

No MeSH data available.


Related in: MedlinePlus