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High dispersity of carbon nanotubes diminishes immunotoxicity in spleen.

Lee S, Khang D, Kim SH - Int J Nanomedicine (2015)

Bottom Line: For cytotoxicity of swCNTs, MTT assay, reactive oxygen species production, superoxide dismutase activity, cellular uptake, and confocal microscopy were used in macrophages.In short, less-dispersed swCNTs caused cytotoxicity in macrophages and abnormalities in immune organs such as spleen, whereas highly dispersed swCNTs did not result in immunotoxicity.Our findings clarified the effective immunotoxicological factors of swCNTs by increasing dispersity of swCNTs and provided useful guidelines for the effective use of nanomaterials.

View Article: PubMed Central - PubMed

Affiliation: CMRI, Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea.

ABSTRACT

Background: From the various physiochemical material properties, the chemical functionalization order of single-walled carbon nanotubes (swCNTs) has not been considered as a critical factor for modulating immunological responses and toxicological aspects in drug delivery applications. Although most nanomaterials, including carbon nanotubes, are specifically accumulated in spleen, few studies have focused on spleen immunotoxicity. For this reason, this study demonstrated that the dispersity of swCNTs significantly influenced immunotoxicity in vitro and in vivo.

Materials and methods: For cytotoxicity of swCNTs, MTT assay, reactive oxygen species production, superoxide dismutase activity, cellular uptake, and confocal microscopy were used in macrophages. In the in vivo study, female BALB/c mice were intravenously administered with 1 mg/kg/day of swCNTs for 2 weeks. The body weight, organ weight, hematological change, reverse-transcription polymerase chain reaction, and lymphocyte population were evaluated.

Results: Different orders of chemical functionalization of swCNTs controlled immunotoxicity. In short, less-dispersed swCNTs caused cytotoxicity in macrophages and abnormalities in immune organs such as spleen, whereas highly dispersed swCNTs did not result in immunotoxicity.

Conclusion: This study clarified that increasing carboxyl groups on swCNTs significantly mitigated immunotoxicity in vitro and in vivo. Our findings clarified the effective immunotoxicological factors of swCNTs by increasing dispersity of swCNTs and provided useful guidelines for the effective use of nanomaterials.

No MeSH data available.


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Effects of dispersed single-walled carbon nanotubes on oxidative stress.Notes: (A) Cells (2×104 cells/well in 96-well plates) were treated with 1 μg/mL swCNTs for 24 hours. After treatment, the cells were stained with 10 μM DHR 123 for 30 minutes. Production of ROS was determined using DHR 123 staining. The fluorescent intensity of DHR was recorded using a fluorescent plate reader. (B) Cells (2×106 cells/well in 6-well plates) were treated with 1 μg/mL swCNTs for 24 hours. Superoxide dismutase (SOD) activity was determined using a tetrazolium-based SOD assay kit. FeSO4 (100 μM) was used as a positive control. The results are presented as mean ± SE of three independent experiments. *P<0.05 significantly different from control.Abbreviations: CON, control; DHR, dihydrorhodamine; ROS, reactive oxygen species; SE, standard error; SOD, superoxide dismutase; swCNT, single-walled carbon nanotube.
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f3-ijn-10-2697: Effects of dispersed single-walled carbon nanotubes on oxidative stress.Notes: (A) Cells (2×104 cells/well in 96-well plates) were treated with 1 μg/mL swCNTs for 24 hours. After treatment, the cells were stained with 10 μM DHR 123 for 30 minutes. Production of ROS was determined using DHR 123 staining. The fluorescent intensity of DHR was recorded using a fluorescent plate reader. (B) Cells (2×106 cells/well in 6-well plates) were treated with 1 μg/mL swCNTs for 24 hours. Superoxide dismutase (SOD) activity was determined using a tetrazolium-based SOD assay kit. FeSO4 (100 μM) was used as a positive control. The results are presented as mean ± SE of three independent experiments. *P<0.05 significantly different from control.Abbreviations: CON, control; DHR, dihydrorhodamine; ROS, reactive oxygen species; SE, standard error; SOD, superoxide dismutase; swCNT, single-walled carbon nanotube.

Mentions: Next, to understand the molecular events involved in swCNT-induced cytotoxicity, the effects of differently dispersed swCNTs on ROS production (Figure 3A) and SOD activity (Figure 3B) were analyzed. Oxidative stress is a common mechanism for cell damage induced by nanoparticles and ultrafine particles, and various nanomaterials have been shown to produce ROS.29,30 ROS are stable and highly reactive compounds that can strip electrons from cellular macromolecules and render them dysfunctional.31 Chain reactions of self-propagating free radicals (molecules that contain an unpaired electron in their outermost shell) mediate lipid peroxidation and cause cell membrane structure damage, thereby inducing cell death.32,33 The accumulation of ROS, superoxide radicals, and hydroxyl free radicals depleted cellular glutathione and minimized the defensive effects of cellular antioxidant enzymes such as SOD.34 In our study, the COOH-max showed much less ROS production and SOD activity than that shown by the less-dispersed swCNTs (Figure 3). These results were confirmed using other immune cell types such as T cells (Jurkat cells) and monocytes (THP-1) (Figure S3). The COOH-max showed less cytotoxicity and ROS production in both Jurkat cells and THP-1. Thus, we concluded that increasing dispersion induces less cytotoxicity and decreased ROS production and SOD activity.


High dispersity of carbon nanotubes diminishes immunotoxicity in spleen.

Lee S, Khang D, Kim SH - Int J Nanomedicine (2015)

Effects of dispersed single-walled carbon nanotubes on oxidative stress.Notes: (A) Cells (2×104 cells/well in 96-well plates) were treated with 1 μg/mL swCNTs for 24 hours. After treatment, the cells were stained with 10 μM DHR 123 for 30 minutes. Production of ROS was determined using DHR 123 staining. The fluorescent intensity of DHR was recorded using a fluorescent plate reader. (B) Cells (2×106 cells/well in 6-well plates) were treated with 1 μg/mL swCNTs for 24 hours. Superoxide dismutase (SOD) activity was determined using a tetrazolium-based SOD assay kit. FeSO4 (100 μM) was used as a positive control. The results are presented as mean ± SE of three independent experiments. *P<0.05 significantly different from control.Abbreviations: CON, control; DHR, dihydrorhodamine; ROS, reactive oxygen species; SE, standard error; SOD, superoxide dismutase; swCNT, single-walled carbon nanotube.
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Related In: Results  -  Collection

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f3-ijn-10-2697: Effects of dispersed single-walled carbon nanotubes on oxidative stress.Notes: (A) Cells (2×104 cells/well in 96-well plates) were treated with 1 μg/mL swCNTs for 24 hours. After treatment, the cells were stained with 10 μM DHR 123 for 30 minutes. Production of ROS was determined using DHR 123 staining. The fluorescent intensity of DHR was recorded using a fluorescent plate reader. (B) Cells (2×106 cells/well in 6-well plates) were treated with 1 μg/mL swCNTs for 24 hours. Superoxide dismutase (SOD) activity was determined using a tetrazolium-based SOD assay kit. FeSO4 (100 μM) was used as a positive control. The results are presented as mean ± SE of three independent experiments. *P<0.05 significantly different from control.Abbreviations: CON, control; DHR, dihydrorhodamine; ROS, reactive oxygen species; SE, standard error; SOD, superoxide dismutase; swCNT, single-walled carbon nanotube.
Mentions: Next, to understand the molecular events involved in swCNT-induced cytotoxicity, the effects of differently dispersed swCNTs on ROS production (Figure 3A) and SOD activity (Figure 3B) were analyzed. Oxidative stress is a common mechanism for cell damage induced by nanoparticles and ultrafine particles, and various nanomaterials have been shown to produce ROS.29,30 ROS are stable and highly reactive compounds that can strip electrons from cellular macromolecules and render them dysfunctional.31 Chain reactions of self-propagating free radicals (molecules that contain an unpaired electron in their outermost shell) mediate lipid peroxidation and cause cell membrane structure damage, thereby inducing cell death.32,33 The accumulation of ROS, superoxide radicals, and hydroxyl free radicals depleted cellular glutathione and minimized the defensive effects of cellular antioxidant enzymes such as SOD.34 In our study, the COOH-max showed much less ROS production and SOD activity than that shown by the less-dispersed swCNTs (Figure 3). These results were confirmed using other immune cell types such as T cells (Jurkat cells) and monocytes (THP-1) (Figure S3). The COOH-max showed less cytotoxicity and ROS production in both Jurkat cells and THP-1. Thus, we concluded that increasing dispersion induces less cytotoxicity and decreased ROS production and SOD activity.

Bottom Line: For cytotoxicity of swCNTs, MTT assay, reactive oxygen species production, superoxide dismutase activity, cellular uptake, and confocal microscopy were used in macrophages.In short, less-dispersed swCNTs caused cytotoxicity in macrophages and abnormalities in immune organs such as spleen, whereas highly dispersed swCNTs did not result in immunotoxicity.Our findings clarified the effective immunotoxicological factors of swCNTs by increasing dispersity of swCNTs and provided useful guidelines for the effective use of nanomaterials.

View Article: PubMed Central - PubMed

Affiliation: CMRI, Department of Pharmacology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea.

ABSTRACT

Background: From the various physiochemical material properties, the chemical functionalization order of single-walled carbon nanotubes (swCNTs) has not been considered as a critical factor for modulating immunological responses and toxicological aspects in drug delivery applications. Although most nanomaterials, including carbon nanotubes, are specifically accumulated in spleen, few studies have focused on spleen immunotoxicity. For this reason, this study demonstrated that the dispersity of swCNTs significantly influenced immunotoxicity in vitro and in vivo.

Materials and methods: For cytotoxicity of swCNTs, MTT assay, reactive oxygen species production, superoxide dismutase activity, cellular uptake, and confocal microscopy were used in macrophages. In the in vivo study, female BALB/c mice were intravenously administered with 1 mg/kg/day of swCNTs for 2 weeks. The body weight, organ weight, hematological change, reverse-transcription polymerase chain reaction, and lymphocyte population were evaluated.

Results: Different orders of chemical functionalization of swCNTs controlled immunotoxicity. In short, less-dispersed swCNTs caused cytotoxicity in macrophages and abnormalities in immune organs such as spleen, whereas highly dispersed swCNTs did not result in immunotoxicity.

Conclusion: This study clarified that increasing carboxyl groups on swCNTs significantly mitigated immunotoxicity in vitro and in vivo. Our findings clarified the effective immunotoxicological factors of swCNTs by increasing dispersity of swCNTs and provided useful guidelines for the effective use of nanomaterials.

No MeSH data available.


Related in: MedlinePlus