Flame Spray Technology

Bergmann, Carlos Pérez; Trommer, Rafael Mello

doi:10.1007/978-3-662-47162-3

Cited by 7 publications

(4 citation statements)

References 37 publications

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“…58 Fumed silica has been generally recognized as safe (GRAS) for use in food products by the Food and Drug Administration (FDA). However, emerging evidence from experimental studies suggests that fumed silica exhibit hazardous potentials due to its siloxane ring structure, high silanol density, and “string-of-pearl-like” aggregate structure, which could combine to cause membrane disruption, generation of reactive oxygen species and pro-inflammatory effects in macrophage and epithelial cells 19,59–60 as well as acute inflammatory responses in animal lungs after inhalation 4 and incidence of liver fibrosis after long term exposure by oral intake.…”

Section: Surface Silanol Density Determines Fumed Silica Induced Plasmentioning

confidence: 99%

Structure activity relationships of engineered nanomaterials in inducing NLRP3 inflammasome activation and chronic lung fibrosis

et al. 2017

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It has been demonstrated that certain engineered nanomaterials (ENMs) could induce chronic lung inflammation and fibrosis, however, the key structure activity relationships (SARs) that the link the physicochemical properties and the fibrogenic effects have not been thoroughly reviewed. Recently, significant progress has been made in our understanding of the SAR, and it has been demonstrated that ENMs including rare earth oxides (REOs), graphene and graphene oxides (GO), fumed silica, as well as high aspect ratio materials (such as CNTs and CeO2 nanowires etc.) could trigger the NLRP3 inflammasome activation and IL-1β production in macrophages and subsequent series of profibrogenic cytokines, i.e. TGF-β1 and PDGF-AA in vitro and in vivo, resulting in synergistically cell-cell communication among macrophages, epithelial cells, and fibroblasts in a process named epithelial-mesenchymal transition (EMT) and collagen deposition in the lung as the adverse outcomes. Interestingly, different ENMs engage a range of distinct pathways leading to the NLRP3 inflammasome activation and IL-1β production in macrophages, which include frustrated phagocytosis, physical piercing, plasma membrane perturbation or damage to lysosomes due to high aspect ratio, particle structure, surface reactivity, transformation, etc. Furthermore, ENM’s properties determine the biopersistence in vivo, which also play a major role in chronic lung fibrosis. Based on these progresses, we reviewed recent findings in the literature on the major SARs leading to chronic lung effects.

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Section: Surface Silanol Density Determines Fumed Silica Induced Plasmentioning

confidence: 99%

Structure activity relationships of engineered nanomaterials in inducing NLRP3 inflammasome activation and chronic lung fibrosis

et al. 2017

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“…For this, the morphology and structure of photocatalyst can be modified by the introduction of dopant additives [9] or accurate (and rather complicated) tuning of the shape of titania NPs [10,11]. At the same time, large-tonnage production of commercial TiO 2 catalysts, such as Aeroxide P25, is based on the pyrolysis of titanium compounds [12,13]. Therefore, postprocessing modification of TiO 2 NPs is more economically feasible for production of visible-range photocatalysts.…”

Section: Introductionmentioning

confidence: 99%

The microstructure effect on the Au/TiO2 and Ag/TiO2 nanocomposites photocatalytic activity

Козлов¹,

Лебедев²,

Polyakov³

et al. 2018

Nanosystems: Phys. Chem. Math.

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In this work the systematic study of the Au/TiO 2 and Ag/TiO 2 nanocomposites was evaluated. Aeroxide P25 preparation was taken as a titania precusor. Composites were obtained using different wet chemistry techniques: impregnation by previously prepared nanoparticles(NPs) sols, in-situ reduction by sodium borohydride, sodium citrate and UV irradiation. The varying of the synthesis method due to the reduction rate differences results in the different interaction between metal NPs and titanium dioxide, and hence different metal/TiO 2 contacts were observed. All the obtained samples were analyzed by XRD, TRS, SEM with EDX and TEM with EDX. According to the statistical analysis of the TEM images the correlation between the metal NPs rate formation and their anisotropy was shown, which may allow us to consider the anisotropy as a descriptor of the contact quality. Combining the results of the optical spectroscopy with the NPs TEM statistical analysis, we confirmed the correlation between observable anisotropy and the contact quality. Finally, the effect of the synthesis method on the photocatalytic activity (PCA) of nanocomposites was shown. Since the work functions of Au and Ag differ, the opposite effects on PCA are expected. Thus, in the case of the Au/TiO 2 nanocomposites, the positive effect associated with NPs anisotropy on the PCA was demonstrated. Alternatively, in the case of the Ag/TiO 2 nanocomposites the PCA evolution was detected only in the case of small NPs formation.

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“…This is an important consideration based on the high production volumes of fumed silica and its widespread use in food, pharmaceuticals, cosmetics, tires, printer toners, coatings, paints, anti-caking agents, etc. 1 In addition to inhalation exposure, it is also important to ponder the effects of gastrointestinal tract (GIT), skin, and eye contact. This should include consideration as to whether the potential hazardous impact on each of these target organs is equivalent.…”

Section: Discussionmentioning

confidence: 99%

“…1 Moreover, the demand for these products are continuing to increase due to their expanded use in foods, pharmaceuticals, cosmetics, printer toners, tires and other industrial applications. 2 Synthetic amorphous silica (SAS), in the form of pyrogenic (fumed), precipitated, gel or colloidal silica is “generally regarded as safe” (GRAS) by the Food and Drug Administrations (FDA).…”

mentioning

confidence: 99%

Repetitive Dosing of Fumed Silica Leads to Profibrogenic Effects through Unique Structure–Activity Relationships and Biopersistence in the Lung

Sun¹,

Wang²,

Liao³

et al. 2016

ACS Nano

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Contrary to the notion that the use of fumed silica in consumer products can “generally (be) regarded as safe” (GRAS), the high surface reactivity of pyrogenic silica differs from other forms of synthetic amorphous silica (SAS), including the capacity to induce acute membrane damage and acute pro-inflammatory changes in the murine lung. In addition, the chain-like structure and reactive surface silanols also allow fumed silica to activate the NLRP3 inflammasome, leading to IL-1β production. This pathway is known to be associated with sub-chronic inflammation and pro-fibrogenic effects in the lung by α-quartz and carbon nanotubes. However, different from the latter materials, bolus dose instillation of 21 mg/kg fumed silica did not induce sustained IL-1β production or sub-chronic pulmonary effects. In contrast, the NLRP3 inflammasome pathway was continuously activated by repetitive dose administration of 3×7 mg/kg fumed silica, one week apart. We also found that while single-dose exposure failed to induce pro-fibrotic effects in the lung, repetitive dosing can trigger increased collagen production, even at 3×3 mg/kg. The change between bolus and repetitive dosing was due to a change in lung clearance, with recurrent dosing leading to fumed silica biopersistence, sustained macrophage recruitment and activation of the NLRP3 pathway. These sub-chronic pro-inflammatory effects disappeared when less surface reactive titanium-doped fumed silica was used for recurrent administration. All considered, these data indicate that while fumed silica may be regarded as safe for some applications, we should reconsider the GRAS label during repetitive or chronic inhalation exposure conditions.

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Flame Spray Technology

Cited by 7 publications

References 37 publications

Structure activity relationships of engineered nanomaterials in inducing NLRP3 inflammasome activation and chronic lung fibrosis

Structure activity relationships of engineered nanomaterials in inducing NLRP3 inflammasome activation and chronic lung fibrosis

The microstructure effect on the Au/TiO2 and Ag/TiO2 nanocomposites photocatalytic activity

Repetitive Dosing of Fumed Silica Leads to Profibrogenic Effects through Unique Structure–Activity Relationships and Biopersistence in the Lung

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