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Adverse effect of nano-silicon dioxide on lung function of rats with or without ovalbumin immunization.

Han B, Guo J, Abrahaley T, Qin L, Wang L, Zheng Y, Li B, Liu D, Yao H, Yang J, Li C, Xi Z, Yang X - PLoS ONE (2011)

Bottom Line: Increased nano-SiO₂ exposure results in adverse changes on inspiratory and expiratory resistance (Ri and Re), but shows insignificant effect on rat lung dynamic compliance (Cldyn).The percentages of eosinophil display an unexpected result, in which higher exposure results lower eosinophil percentages.The results suggested that intratracheal administration of nano-SiO₂ could lead to the airway hyperresponsiveness (AHR) and the airway remolding with or without OVA immunization.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Environmental Sciences and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Huazhong Normal University, Wuhan, China.

ABSTRACT

Background: The great advances of nanomaterials have brought out broad important applications, but their possible nanotoxicity and risks have not been fully understood. It is confirmed that exposure of environmental particulate matter (PM), especially ultrafine PM, are responsible for many lung function impairment and exacerbation of pre-existing lung diseases. However, the adverse effect of nanoparticles on allergic asthma is seldom investigated and the mechanism remains undefined. For the first time, this work investigates the relationship between allergic asthma and nanosized silicon dioxide (nano-SiO₂).

Methodology/principal findings: Ovalbumin (OVA)-treated and saline-treated control rats were daily intratracheally administered 0.1 ml of 0, 40 and 80 µg/ml nano-SiO₂ solutions, respectively for 30 days. Increased nano-SiO₂ exposure results in adverse changes on inspiratory and expiratory resistance (Ri and Re), but shows insignificant effect on rat lung dynamic compliance (Cldyn). Lung histological observation reveals obvious airway remodeling in 80 µg/ml nano-SiO₂-introduced saline and OVA groups, but the latter is worse. Additionally, increased nano-SiO₂ exposure also leads to more severe inflammation. With increasing nano-SiO₂ exposure, IL-4 in lung homogenate increases and IFN-γ shows a reverse but insignificant change. Moreover, at a same nano-SiO₂ exposure concentration, OVA-treated rats exhibit higher (significant) IL-4 and lower (not significant) IFN-γ compared with the saline-treated rats. The percentages of eosinophil display an unexpected result, in which higher exposure results lower eosinophil percentages.

Conclusions/significance: This was a preliminary study which for the first time involved the effect of nano-SiO₂ to OVA induced rat asthma model. The results suggested that intratracheal administration of nano-SiO₂ could lead to the airway hyperresponsiveness (AHR) and the airway remolding with or without OVA immunization. This occurrence may be due to the Th1/Th2 cytokine imbalance accelerated by the nano-SiO₂ through increasing the tissue IL-4 production.

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Related in: MedlinePlus

SEM images of nano-SiO2 (a) and nor-SiO2 (b).(JEOL-6700F).
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pone-0017236-g001: SEM images of nano-SiO2 (a) and nor-SiO2 (b).(JEOL-6700F).

Mentions: Silica nanoparticles with diameters of 10–20 nm, 99.5% purity and BET surface area ranged from 140–180 m2/g were purchased from Sigma-Aldrich (USA). Scanning electron microscopy (SEM) images of the material were obtained by JEOL-6700F (Fig. 1) and compared with an SEM image of normal-sized SiO2 (nor-SiO2, 5–10 µm, Sinopharm, China) taken previously. The distilled water was used to prepare the mother solution (800 µg/ml). The prepared mother solution was sterilized at 120°C for 20 min to avoid the aggregation of nano-SiO2 induce by various microbes during our experimental period. The mother solution was daily stirred for 1 h followed by ultrasonicating for another hour to avoid clumping before each use. The exposure solutions (40 and 80 µg/ml) were freshly prepared by diluting the mother solution in distilled water and were ultrasonificated for another 15 min before its intretracheal instillation. After this process, both exposure solutions were stable for at least 24 h. Because the exposure solutions were freshly prepared before use, so sterilization for the two exposure solutions were not conducted.


Adverse effect of nano-silicon dioxide on lung function of rats with or without ovalbumin immunization.

Han B, Guo J, Abrahaley T, Qin L, Wang L, Zheng Y, Li B, Liu D, Yao H, Yang J, Li C, Xi Z, Yang X - PLoS ONE (2011)

SEM images of nano-SiO2 (a) and nor-SiO2 (b).(JEOL-6700F).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3040772&req=5

pone-0017236-g001: SEM images of nano-SiO2 (a) and nor-SiO2 (b).(JEOL-6700F).
Mentions: Silica nanoparticles with diameters of 10–20 nm, 99.5% purity and BET surface area ranged from 140–180 m2/g were purchased from Sigma-Aldrich (USA). Scanning electron microscopy (SEM) images of the material were obtained by JEOL-6700F (Fig. 1) and compared with an SEM image of normal-sized SiO2 (nor-SiO2, 5–10 µm, Sinopharm, China) taken previously. The distilled water was used to prepare the mother solution (800 µg/ml). The prepared mother solution was sterilized at 120°C for 20 min to avoid the aggregation of nano-SiO2 induce by various microbes during our experimental period. The mother solution was daily stirred for 1 h followed by ultrasonicating for another hour to avoid clumping before each use. The exposure solutions (40 and 80 µg/ml) were freshly prepared by diluting the mother solution in distilled water and were ultrasonificated for another 15 min before its intretracheal instillation. After this process, both exposure solutions were stable for at least 24 h. Because the exposure solutions were freshly prepared before use, so sterilization for the two exposure solutions were not conducted.

Bottom Line: Increased nano-SiO₂ exposure results in adverse changes on inspiratory and expiratory resistance (Ri and Re), but shows insignificant effect on rat lung dynamic compliance (Cldyn).The percentages of eosinophil display an unexpected result, in which higher exposure results lower eosinophil percentages.The results suggested that intratracheal administration of nano-SiO₂ could lead to the airway hyperresponsiveness (AHR) and the airway remolding with or without OVA immunization.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Environmental Sciences and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Huazhong Normal University, Wuhan, China.

ABSTRACT

Background: The great advances of nanomaterials have brought out broad important applications, but their possible nanotoxicity and risks have not been fully understood. It is confirmed that exposure of environmental particulate matter (PM), especially ultrafine PM, are responsible for many lung function impairment and exacerbation of pre-existing lung diseases. However, the adverse effect of nanoparticles on allergic asthma is seldom investigated and the mechanism remains undefined. For the first time, this work investigates the relationship between allergic asthma and nanosized silicon dioxide (nano-SiO₂).

Methodology/principal findings: Ovalbumin (OVA)-treated and saline-treated control rats were daily intratracheally administered 0.1 ml of 0, 40 and 80 µg/ml nano-SiO₂ solutions, respectively for 30 days. Increased nano-SiO₂ exposure results in adverse changes on inspiratory and expiratory resistance (Ri and Re), but shows insignificant effect on rat lung dynamic compliance (Cldyn). Lung histological observation reveals obvious airway remodeling in 80 µg/ml nano-SiO₂-introduced saline and OVA groups, but the latter is worse. Additionally, increased nano-SiO₂ exposure also leads to more severe inflammation. With increasing nano-SiO₂ exposure, IL-4 in lung homogenate increases and IFN-γ shows a reverse but insignificant change. Moreover, at a same nano-SiO₂ exposure concentration, OVA-treated rats exhibit higher (significant) IL-4 and lower (not significant) IFN-γ compared with the saline-treated rats. The percentages of eosinophil display an unexpected result, in which higher exposure results lower eosinophil percentages.

Conclusions/significance: This was a preliminary study which for the first time involved the effect of nano-SiO₂ to OVA induced rat asthma model. The results suggested that intratracheal administration of nano-SiO₂ could lead to the airway hyperresponsiveness (AHR) and the airway remolding with or without OVA immunization. This occurrence may be due to the Th1/Th2 cytokine imbalance accelerated by the nano-SiO₂ through increasing the tissue IL-4 production.

Show MeSH
Related in: MedlinePlus