Limits...
Reducing X-Ray Induced Oxidative Damages in Fibroblasts with Graphene Oxide.

Qiao Y, Zhang P, Wang C, Ma L, Su M - Nanomaterials (Basel) (2014)

Bottom Line: A major issue of X-ray radiation therapy is that normal cells can be damaged, limiting the amount of X-rays that can be safely delivered to a tumor.A variety of techniques such as cytotoxicity, genotoxicity, oxidative assay, apoptosis, γ-H2AX expression, and micro-nucleus assay have been used to assess the protective effect of GO in cultured fibroblast cells.Thus, low concentration GO can be used as an effective radio-protective agent in occupational and therapeutic settings.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA 01609, USA.

ABSTRACT

A major issue of X-ray radiation therapy is that normal cells can be damaged, limiting the amount of X-rays that can be safely delivered to a tumor. This paper describes a new method based on graphene oxide (GO) to protect normal cells from oxidative damage by removing free radicals generated by X-ray radiation using grapheme oxide (GO). A variety of techniques such as cytotoxicity, genotoxicity, oxidative assay, apoptosis, γ-H2AX expression, and micro-nucleus assay have been used to assess the protective effect of GO in cultured fibroblast cells. It is found that although GO at higher concentration (100 and 500 μg/mL) can cause cell death and DNA damage, it can effectively remove oxygen free radicals at a lower concentration of 10 μg/mL. The level of DNA damage and cell death is reduced by 48%, and 39%, respectively. Thus, low concentration GO can be used as an effective radio-protective agent in occupational and therapeutic settings.

No MeSH data available.


Related in: MedlinePlus

Genotoxicity of cells treated with GO and X-ray irradiation with halo assay. Fluorescent images of arrayed cells (A); cells treated with 10 μg/mL GO (B); cells exposed to 1.25 Gy X-ray (C); and cells treated with GO and then exposed to 1.25 Gy X-ray (D); an enlarged image shows that halo and nucleus (E); the NDF values of cells after different treatment (F); the rNDF values of cells treated with different concentration of GO without (G) and with 1.25 Gy X-ray radiations (H). “*” (p < 0.05) and “**” (p < 0.01) represent significant difference and extra significant difference, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4269382&req=5

Figure 2: Genotoxicity of cells treated with GO and X-ray irradiation with halo assay. Fluorescent images of arrayed cells (A); cells treated with 10 μg/mL GO (B); cells exposed to 1.25 Gy X-ray (C); and cells treated with GO and then exposed to 1.25 Gy X-ray (D); an enlarged image shows that halo and nucleus (E); the NDF values of cells after different treatment (F); the rNDF values of cells treated with different concentration of GO without (G) and with 1.25 Gy X-ray radiations (H). “*” (p < 0.05) and “**” (p < 0.01) represent significant difference and extra significant difference, respectively.

Mentions: DNA damage in cells has been studied with HaloChip assay after embedding cells in agarose gel [30]. SYBR Green I dye is used to label DNA. Figure 2A shows a fluorescent image of the control group, which is not treated with GO, and not exposed to X-ray. Here there is no DNA diffusion from nucleus. Figure 2B shows a fluorescent image of cell array after incubated with 10 μg/mL GO for 24 h, where GO does not cause DNA damage. Figure 2C shows fluorescent image of arrayed cells that are exposed to 1.25 Gy X-ray radiations, where more DNA damage can be found to form diffusive halo around nuclei. Figure 2D shows fluorescent image of arrayed cells that are pretreated with GO and then exposed to X-ray radiation. A relative nuclear diffusion factor (rNDF) is used to quantify the level of DNA damage. rNDF is defined as rNDF = (R2 − r2)/r2, where R and r are the radii of large circle and small circle in Figure 2E, respectively. Figure 2F shows rNDF values of (1) cells; (2) cells treated with 10 μg/mL GO; (3) cells exposed to 1.25 Gy X-ray; and (4) cells treated with 10 μg/mL GO, and then exposed to 1.25 Gy X-ray. The level of DNA damage in sample (4) is lower than that in sample (3), suggesting that GO treatment can effectively prevent X-ray induced DNA damage. In addition, cells were also treated with 10 μg/mL of melatonin and carbon nanotubes (CNTs), and exposed to 1.25 Gy X-ray. The NDF value of melatonin is slightly smaller than GO, suggesting that GO is slightly weaker than melatonin in removing free radicals. This is likely due to the fact that melatonin (being molecules) can be dispersed better than GO (macromolecules). Meanwhile, the NDF value of sample exposed to CNTs and X-ray is similar as that treated with X-ray alone. So CNTs cannot remove ROS generated by X-ray as effective as GO due to its close structure. Figure 2G shows rNDF values of cells treated with different concentration of GO for 24 h, where concentration dependent DNA damage can be found. At low concentrations (1 and 10 μg/mL), GO itself does not cause DNA damage; but at high concentration (100 and 500 μg/mL), GO can cause significant DNA damage. Figure 2H shows rNDF values of cells treated with different concentration of GO for 24 h, and then exposed to 1.25 Gy X-ray, where DNA damage can be reduced at all concentration of GO, with less DNA damage at high GO concentration.


Reducing X-Ray Induced Oxidative Damages in Fibroblasts with Graphene Oxide.

Qiao Y, Zhang P, Wang C, Ma L, Su M - Nanomaterials (Basel) (2014)

Genotoxicity of cells treated with GO and X-ray irradiation with halo assay. Fluorescent images of arrayed cells (A); cells treated with 10 μg/mL GO (B); cells exposed to 1.25 Gy X-ray (C); and cells treated with GO and then exposed to 1.25 Gy X-ray (D); an enlarged image shows that halo and nucleus (E); the NDF values of cells after different treatment (F); the rNDF values of cells treated with different concentration of GO without (G) and with 1.25 Gy X-ray radiations (H). “*” (p < 0.05) and “**” (p < 0.01) represent significant difference and extra significant difference, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4269382&req=5

Figure 2: Genotoxicity of cells treated with GO and X-ray irradiation with halo assay. Fluorescent images of arrayed cells (A); cells treated with 10 μg/mL GO (B); cells exposed to 1.25 Gy X-ray (C); and cells treated with GO and then exposed to 1.25 Gy X-ray (D); an enlarged image shows that halo and nucleus (E); the NDF values of cells after different treatment (F); the rNDF values of cells treated with different concentration of GO without (G) and with 1.25 Gy X-ray radiations (H). “*” (p < 0.05) and “**” (p < 0.01) represent significant difference and extra significant difference, respectively.
Mentions: DNA damage in cells has been studied with HaloChip assay after embedding cells in agarose gel [30]. SYBR Green I dye is used to label DNA. Figure 2A shows a fluorescent image of the control group, which is not treated with GO, and not exposed to X-ray. Here there is no DNA diffusion from nucleus. Figure 2B shows a fluorescent image of cell array after incubated with 10 μg/mL GO for 24 h, where GO does not cause DNA damage. Figure 2C shows fluorescent image of arrayed cells that are exposed to 1.25 Gy X-ray radiations, where more DNA damage can be found to form diffusive halo around nuclei. Figure 2D shows fluorescent image of arrayed cells that are pretreated with GO and then exposed to X-ray radiation. A relative nuclear diffusion factor (rNDF) is used to quantify the level of DNA damage. rNDF is defined as rNDF = (R2 − r2)/r2, where R and r are the radii of large circle and small circle in Figure 2E, respectively. Figure 2F shows rNDF values of (1) cells; (2) cells treated with 10 μg/mL GO; (3) cells exposed to 1.25 Gy X-ray; and (4) cells treated with 10 μg/mL GO, and then exposed to 1.25 Gy X-ray. The level of DNA damage in sample (4) is lower than that in sample (3), suggesting that GO treatment can effectively prevent X-ray induced DNA damage. In addition, cells were also treated with 10 μg/mL of melatonin and carbon nanotubes (CNTs), and exposed to 1.25 Gy X-ray. The NDF value of melatonin is slightly smaller than GO, suggesting that GO is slightly weaker than melatonin in removing free radicals. This is likely due to the fact that melatonin (being molecules) can be dispersed better than GO (macromolecules). Meanwhile, the NDF value of sample exposed to CNTs and X-ray is similar as that treated with X-ray alone. So CNTs cannot remove ROS generated by X-ray as effective as GO due to its close structure. Figure 2G shows rNDF values of cells treated with different concentration of GO for 24 h, where concentration dependent DNA damage can be found. At low concentrations (1 and 10 μg/mL), GO itself does not cause DNA damage; but at high concentration (100 and 500 μg/mL), GO can cause significant DNA damage. Figure 2H shows rNDF values of cells treated with different concentration of GO for 24 h, and then exposed to 1.25 Gy X-ray, where DNA damage can be reduced at all concentration of GO, with less DNA damage at high GO concentration.

Bottom Line: A major issue of X-ray radiation therapy is that normal cells can be damaged, limiting the amount of X-rays that can be safely delivered to a tumor.A variety of techniques such as cytotoxicity, genotoxicity, oxidative assay, apoptosis, γ-H2AX expression, and micro-nucleus assay have been used to assess the protective effect of GO in cultured fibroblast cells.Thus, low concentration GO can be used as an effective radio-protective agent in occupational and therapeutic settings.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA 01609, USA.

ABSTRACT

A major issue of X-ray radiation therapy is that normal cells can be damaged, limiting the amount of X-rays that can be safely delivered to a tumor. This paper describes a new method based on graphene oxide (GO) to protect normal cells from oxidative damage by removing free radicals generated by X-ray radiation using grapheme oxide (GO). A variety of techniques such as cytotoxicity, genotoxicity, oxidative assay, apoptosis, γ-H2AX expression, and micro-nucleus assay have been used to assess the protective effect of GO in cultured fibroblast cells. It is found that although GO at higher concentration (100 and 500 μg/mL) can cause cell death and DNA damage, it can effectively remove oxygen free radicals at a lower concentration of 10 μg/mL. The level of DNA damage and cell death is reduced by 48%, and 39%, respectively. Thus, low concentration GO can be used as an effective radio-protective agent in occupational and therapeutic settings.

No MeSH data available.


Related in: MedlinePlus