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Surface coatings of ZnO nanoparticles mitigate differentially a host of transcriptional, protein and signalling responses in primary human olfactory cells.

Osmond-McLeod MJ, Osmond RI, Oytam Y, McCall MJ, Feltis B, Mackay-Sim A, Wood SA, Cook AL - Part Fibre Toxicol (2013)

Bottom Line: Four types of commercially-available zinc oxide (ZnO) nanoparticles, two coated and two uncoated, were examined for their effects on primary human cells cultured from the olfactory mucosa.ZnO nanoparticle toxicity in hONS cells was mediated through a battery of mechanisms largely related to cell stress, inflammatory response and apoptosis, but not activation of mechanisms that repair damaged DNA.Surface coatings on the ZnO nanoparticles mitigated these cellular responses to varying degrees.

View Article: PubMed Central - HTML - PubMed

Affiliation: CSIRO Advanced Materials TCP (Nanosafety), and CSIRO Animal, Food and Health Sciences, PO Box 52, North Ryde, NSW 1670, Australia. megan.osmond@csiro.au.

ABSTRACT

Background: Inhaled nanoparticles have been reported in some instances to translocate from the nostril to the olfactory bulb in exposed rats. In close proximity to the olfactory bulb is the olfactory mucosa, within which resides a niche of multipotent cells. Cells isolated from this area may provide a relevant in vitro system to investigate potential effects of workplace exposure to inhaled zinc oxide nanoparticles.

Methods: Four types of commercially-available zinc oxide (ZnO) nanoparticles, two coated and two uncoated, were examined for their effects on primary human cells cultured from the olfactory mucosa. Human olfactory neurosphere-derived (hONS) cells from healthy adult donors were analyzed for modulation of cytokine levels, activation of intracellular signalling pathways, changes in gene-expression patterns across the whole genome, and compromised cellular function over a 24 h period following exposure to the nanoparticles suspended in cell culture medium.

Results: ZnO nanoparticle toxicity in hONS cells was mediated through a battery of mechanisms largely related to cell stress, inflammatory response and apoptosis, but not activation of mechanisms that repair damaged DNA. Surface coatings on the ZnO nanoparticles mitigated these cellular responses to varying degrees.

Conclusions: The results indicate that care should be taken in the workplace to minimize generation of, and exposure to, aerosols of uncoated ZnO nanoparticles, given the adverse responses reported here using multipotent cells derived from the olfactory mucosa.

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Related in: MedlinePlus

Experimental overview. Nanoparticles were characterised as powders or dispersions in aqueous media (top left), and also as dispersions in DMEM cell-culture medium (top right). An initial concentration response curve was generated to select an appropriate treatment concentration that elicited a mechanistic response in hONS cells for at least one of the ZnO products. hONS cells were exposed to ZnO products at the selected concentration (25 μg/mL) for up to 24 h, after which the cellular responses to treatment were measured by a variety of assays. ‡ Cells from four human donors, A, B, C and D, each in three replicate wells for each treatment time-point (2 h, 6 h and 24 h); * Donor A cells, in three replicate wells for each treatment time-point (2 h and 6 h); † Donor A cells, in four replicate wells for each treatment time-point (2 h, 4 h, 6 h, 8 h, and 10 h); ** Donor A cells, in four replicate wells for each treatment time-point (2 h and 6 h).
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Figure 1: Experimental overview. Nanoparticles were characterised as powders or dispersions in aqueous media (top left), and also as dispersions in DMEM cell-culture medium (top right). An initial concentration response curve was generated to select an appropriate treatment concentration that elicited a mechanistic response in hONS cells for at least one of the ZnO products. hONS cells were exposed to ZnO products at the selected concentration (25 μg/mL) for up to 24 h, after which the cellular responses to treatment were measured by a variety of assays. ‡ Cells from four human donors, A, B, C and D, each in three replicate wells for each treatment time-point (2 h, 6 h and 24 h); * Donor A cells, in three replicate wells for each treatment time-point (2 h and 6 h); † Donor A cells, in four replicate wells for each treatment time-point (2 h, 4 h, 6 h, 8 h, and 10 h); ** Donor A cells, in four replicate wells for each treatment time-point (2 h and 6 h).

Mentions: A scheme summarising our experimental approach, including particle characterisation and specific assays used to measure cellular responses to the nanoparticles, is shown in Figure 1. Four types of commercially-available ZnO particles were assessed. Two were uncoated (Z-COTE from BASF, and Nanosun P99/30 (hereafter referred to as Nanosun) from Micronisers) and two were coated (Z-COTE HP1 and Z-COTE MAX, both from BASF). Z-COTE HP1 (referred to as HP1) is coated with triethoxycaprylylsilane, and Z-COTE MAX (referred to as MAX) is coated with a dimethoxydiphenylsilane/triethoxycaprylylsilane crosspolymer. Our first experiments were nine cell stress and viability assays (lower-right side of Figure 1), using hONS cells derived from each of four human donors A, B, C and D. Three replicate wells for each ZnO treatment time-point were used for each assay. While some biological variation was present between the four donors, treatment effects typically far outweighed biological variations between the donors. For subsequent experiments (cytokine, cell signalling, and whole-genome gene expression) we used cells from donor A, where three to four replicate wells for each treatment time-point were used. Thus, by generating information on a very large number and variety of endpoints, the systemic responses of hONS cells exposed to commercial samples of coated and uncoated ZnO nanoparticles could be identified.


Surface coatings of ZnO nanoparticles mitigate differentially a host of transcriptional, protein and signalling responses in primary human olfactory cells.

Osmond-McLeod MJ, Osmond RI, Oytam Y, McCall MJ, Feltis B, Mackay-Sim A, Wood SA, Cook AL - Part Fibre Toxicol (2013)

Experimental overview. Nanoparticles were characterised as powders or dispersions in aqueous media (top left), and also as dispersions in DMEM cell-culture medium (top right). An initial concentration response curve was generated to select an appropriate treatment concentration that elicited a mechanistic response in hONS cells for at least one of the ZnO products. hONS cells were exposed to ZnO products at the selected concentration (25 μg/mL) for up to 24 h, after which the cellular responses to treatment were measured by a variety of assays. ‡ Cells from four human donors, A, B, C and D, each in three replicate wells for each treatment time-point (2 h, 6 h and 24 h); * Donor A cells, in three replicate wells for each treatment time-point (2 h and 6 h); † Donor A cells, in four replicate wells for each treatment time-point (2 h, 4 h, 6 h, 8 h, and 10 h); ** Donor A cells, in four replicate wells for each treatment time-point (2 h and 6 h).
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4016547&req=5

Figure 1: Experimental overview. Nanoparticles were characterised as powders or dispersions in aqueous media (top left), and also as dispersions in DMEM cell-culture medium (top right). An initial concentration response curve was generated to select an appropriate treatment concentration that elicited a mechanistic response in hONS cells for at least one of the ZnO products. hONS cells were exposed to ZnO products at the selected concentration (25 μg/mL) for up to 24 h, after which the cellular responses to treatment were measured by a variety of assays. ‡ Cells from four human donors, A, B, C and D, each in three replicate wells for each treatment time-point (2 h, 6 h and 24 h); * Donor A cells, in three replicate wells for each treatment time-point (2 h and 6 h); † Donor A cells, in four replicate wells for each treatment time-point (2 h, 4 h, 6 h, 8 h, and 10 h); ** Donor A cells, in four replicate wells for each treatment time-point (2 h and 6 h).
Mentions: A scheme summarising our experimental approach, including particle characterisation and specific assays used to measure cellular responses to the nanoparticles, is shown in Figure 1. Four types of commercially-available ZnO particles were assessed. Two were uncoated (Z-COTE from BASF, and Nanosun P99/30 (hereafter referred to as Nanosun) from Micronisers) and two were coated (Z-COTE HP1 and Z-COTE MAX, both from BASF). Z-COTE HP1 (referred to as HP1) is coated with triethoxycaprylylsilane, and Z-COTE MAX (referred to as MAX) is coated with a dimethoxydiphenylsilane/triethoxycaprylylsilane crosspolymer. Our first experiments were nine cell stress and viability assays (lower-right side of Figure 1), using hONS cells derived from each of four human donors A, B, C and D. Three replicate wells for each ZnO treatment time-point were used for each assay. While some biological variation was present between the four donors, treatment effects typically far outweighed biological variations between the donors. For subsequent experiments (cytokine, cell signalling, and whole-genome gene expression) we used cells from donor A, where three to four replicate wells for each treatment time-point were used. Thus, by generating information on a very large number and variety of endpoints, the systemic responses of hONS cells exposed to commercial samples of coated and uncoated ZnO nanoparticles could be identified.

Bottom Line: Four types of commercially-available zinc oxide (ZnO) nanoparticles, two coated and two uncoated, were examined for their effects on primary human cells cultured from the olfactory mucosa.ZnO nanoparticle toxicity in hONS cells was mediated through a battery of mechanisms largely related to cell stress, inflammatory response and apoptosis, but not activation of mechanisms that repair damaged DNA.Surface coatings on the ZnO nanoparticles mitigated these cellular responses to varying degrees.

View Article: PubMed Central - HTML - PubMed

Affiliation: CSIRO Advanced Materials TCP (Nanosafety), and CSIRO Animal, Food and Health Sciences, PO Box 52, North Ryde, NSW 1670, Australia. megan.osmond@csiro.au.

ABSTRACT

Background: Inhaled nanoparticles have been reported in some instances to translocate from the nostril to the olfactory bulb in exposed rats. In close proximity to the olfactory bulb is the olfactory mucosa, within which resides a niche of multipotent cells. Cells isolated from this area may provide a relevant in vitro system to investigate potential effects of workplace exposure to inhaled zinc oxide nanoparticles.

Methods: Four types of commercially-available zinc oxide (ZnO) nanoparticles, two coated and two uncoated, were examined for their effects on primary human cells cultured from the olfactory mucosa. Human olfactory neurosphere-derived (hONS) cells from healthy adult donors were analyzed for modulation of cytokine levels, activation of intracellular signalling pathways, changes in gene-expression patterns across the whole genome, and compromised cellular function over a 24 h period following exposure to the nanoparticles suspended in cell culture medium.

Results: ZnO nanoparticle toxicity in hONS cells was mediated through a battery of mechanisms largely related to cell stress, inflammatory response and apoptosis, but not activation of mechanisms that repair damaged DNA. Surface coatings on the ZnO nanoparticles mitigated these cellular responses to varying degrees.

Conclusions: The results indicate that care should be taken in the workplace to minimize generation of, and exposure to, aerosols of uncoated ZnO nanoparticles, given the adverse responses reported here using multipotent cells derived from the olfactory mucosa.

Show MeSH
Related in: MedlinePlus