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Exposure to titanium dioxide and other metallic oxide nanoparticles induces cytotoxicity on human neural cells and fibroblasts.

Lai JC, Lai MB, Jandhyam S, Dukhande VV, Bhushan A, Daniels CK, Leung SW - Int J Nanomedicine (2008)

Bottom Line: Because the effects of such nanoparticles on human neural cells are unknown, we have determined the putative cytotoxic effects of these nanoparticles on human astrocytes-like astrocytoma U87 cells and compared their effects on normal human fibroblasts.We further noted that zinc oxide (ZnO) nanoparticles were the most effective, TiO(2) nanoparticles the second most effective, and magnesium oxide (MgO) nanoparticles the least effective in inducing cell death in U87 cells.Thus, our findings may have toxicological and other pathophysiological implications on exposure of humans and other mammalian species to metallic oxide nanoparticles.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, Idaho State University, Pocatello, ID 83209, USA.

ABSTRACT
The use of titanium dioxide (TiO(2)) in various industrial applications (eg, production of paper, plastics, cosmetics, and paints) has been expanding thereby increasing the occupational and other environmental exposure of these nanoparticles to humans and other species. However, the health effects of exposure to TiO(2) nanoparticles have not been systematically assessed even though recent studies suggest that such exposure induces inflammatory responses in lung tissue and cells. Because the effects of such nanoparticles on human neural cells are unknown, we have determined the putative cytotoxic effects of these nanoparticles on human astrocytes-like astrocytoma U87 cells and compared their effects on normal human fibroblasts. We found that TiO(2) micro- and nanoparticles induced cell death on both human cell types in a concentration-related manner. We further noted that zinc oxide (ZnO) nanoparticles were the most effective, TiO(2) nanoparticles the second most effective, and magnesium oxide (MgO) nanoparticles the least effective in inducing cell death in U87 cells. The cell death mechanisms underlying the effects of TiO(2) micro- and nanoparticles on U87 cells include apoptosis, necrosis, and possibly apoptosis-like and necrosis-like cell death types. Thus, our findings may have toxicological and other pathophysiological implications on exposure of humans and other mammalian species to metallic oxide nanoparticles.

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Related in: MedlinePlus

Effects of ZnO and MgO nanoparticles on human astrocytoma (astrocytes-like) U87 cells.Notes: Values are mean ± SEM of 6–9 determinations. U87 cells treated with ZnO nanoparticles are marked with open squares and those treated with MgO nanoparticles are marked with open circles. Values marked with a and b are significantly different (p < 0.05, by ANOVA and post-hoc Student–Newman–Keuls test) from corresponding mean value in control (ie, untreated) cells.Abbreviations: ANOVA, analysis of variance; MgO, magnesium oxide; SEM, standard error of mean; ZnO, zinc oxide.
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f2-ijn-3-533: Effects of ZnO and MgO nanoparticles on human astrocytoma (astrocytes-like) U87 cells.Notes: Values are mean ± SEM of 6–9 determinations. U87 cells treated with ZnO nanoparticles are marked with open squares and those treated with MgO nanoparticles are marked with open circles. Values marked with a and b are significantly different (p < 0.05, by ANOVA and post-hoc Student–Newman–Keuls test) from corresponding mean value in control (ie, untreated) cells.Abbreviations: ANOVA, analysis of variance; MgO, magnesium oxide; SEM, standard error of mean; ZnO, zinc oxide.

Mentions: To assess if other metallic oxide nanoparticles may exert cytotoxicity on human neural cells similar to those of TiO2 micro- and nanoparticles, we also studied the effects of nanoparticles of two oxides of essential metals, namely ZnO and MgO, on U87 cells. Exposure of these cells to ZnO for 48 hours at concentrations higher than 1 μg/mL induced a concentration-related decreases in cell survival, with an IC50 of ∼11 μg/mL (Figure 2); at concentrations of ZnO nanoparticles higher than 20 μg/mL, cell survival decreased to less than 5% of that of untreated (ie control) cells (Figure 2). In contrast with the effect of ZnO nanoparticles, treatment of U87 cells with MgO nanoparticles for 48 hours did not significantly decrease their survival until the concentrations were higher than 50 μg/mL (Figure 2). Nevertheless, even at the highest concentration employed (ie, 100 μg/mL), MgO nanoparticles only did induce approximately 35% decrease in U87 cell survival, indicating that at the concentration range employed, MgO nanoparticles were less cytotoxic to these cells than ZnO nanoparticles (Figure 2).


Exposure to titanium dioxide and other metallic oxide nanoparticles induces cytotoxicity on human neural cells and fibroblasts.

Lai JC, Lai MB, Jandhyam S, Dukhande VV, Bhushan A, Daniels CK, Leung SW - Int J Nanomedicine (2008)

Effects of ZnO and MgO nanoparticles on human astrocytoma (astrocytes-like) U87 cells.Notes: Values are mean ± SEM of 6–9 determinations. U87 cells treated with ZnO nanoparticles are marked with open squares and those treated with MgO nanoparticles are marked with open circles. Values marked with a and b are significantly different (p < 0.05, by ANOVA and post-hoc Student–Newman–Keuls test) from corresponding mean value in control (ie, untreated) cells.Abbreviations: ANOVA, analysis of variance; MgO, magnesium oxide; SEM, standard error of mean; ZnO, zinc oxide.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2636591&req=5

f2-ijn-3-533: Effects of ZnO and MgO nanoparticles on human astrocytoma (astrocytes-like) U87 cells.Notes: Values are mean ± SEM of 6–9 determinations. U87 cells treated with ZnO nanoparticles are marked with open squares and those treated with MgO nanoparticles are marked with open circles. Values marked with a and b are significantly different (p < 0.05, by ANOVA and post-hoc Student–Newman–Keuls test) from corresponding mean value in control (ie, untreated) cells.Abbreviations: ANOVA, analysis of variance; MgO, magnesium oxide; SEM, standard error of mean; ZnO, zinc oxide.
Mentions: To assess if other metallic oxide nanoparticles may exert cytotoxicity on human neural cells similar to those of TiO2 micro- and nanoparticles, we also studied the effects of nanoparticles of two oxides of essential metals, namely ZnO and MgO, on U87 cells. Exposure of these cells to ZnO for 48 hours at concentrations higher than 1 μg/mL induced a concentration-related decreases in cell survival, with an IC50 of ∼11 μg/mL (Figure 2); at concentrations of ZnO nanoparticles higher than 20 μg/mL, cell survival decreased to less than 5% of that of untreated (ie control) cells (Figure 2). In contrast with the effect of ZnO nanoparticles, treatment of U87 cells with MgO nanoparticles for 48 hours did not significantly decrease their survival until the concentrations were higher than 50 μg/mL (Figure 2). Nevertheless, even at the highest concentration employed (ie, 100 μg/mL), MgO nanoparticles only did induce approximately 35% decrease in U87 cell survival, indicating that at the concentration range employed, MgO nanoparticles were less cytotoxic to these cells than ZnO nanoparticles (Figure 2).

Bottom Line: Because the effects of such nanoparticles on human neural cells are unknown, we have determined the putative cytotoxic effects of these nanoparticles on human astrocytes-like astrocytoma U87 cells and compared their effects on normal human fibroblasts.We further noted that zinc oxide (ZnO) nanoparticles were the most effective, TiO(2) nanoparticles the second most effective, and magnesium oxide (MgO) nanoparticles the least effective in inducing cell death in U87 cells.Thus, our findings may have toxicological and other pathophysiological implications on exposure of humans and other mammalian species to metallic oxide nanoparticles.

View Article: PubMed Central - PubMed

Affiliation: Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, Idaho State University, Pocatello, ID 83209, USA.

ABSTRACT
The use of titanium dioxide (TiO(2)) in various industrial applications (eg, production of paper, plastics, cosmetics, and paints) has been expanding thereby increasing the occupational and other environmental exposure of these nanoparticles to humans and other species. However, the health effects of exposure to TiO(2) nanoparticles have not been systematically assessed even though recent studies suggest that such exposure induces inflammatory responses in lung tissue and cells. Because the effects of such nanoparticles on human neural cells are unknown, we have determined the putative cytotoxic effects of these nanoparticles on human astrocytes-like astrocytoma U87 cells and compared their effects on normal human fibroblasts. We found that TiO(2) micro- and nanoparticles induced cell death on both human cell types in a concentration-related manner. We further noted that zinc oxide (ZnO) nanoparticles were the most effective, TiO(2) nanoparticles the second most effective, and magnesium oxide (MgO) nanoparticles the least effective in inducing cell death in U87 cells. The cell death mechanisms underlying the effects of TiO(2) micro- and nanoparticles on U87 cells include apoptosis, necrosis, and possibly apoptosis-like and necrosis-like cell death types. Thus, our findings may have toxicological and other pathophysiological implications on exposure of humans and other mammalian species to metallic oxide nanoparticles.

Show MeSH
Related in: MedlinePlus