ArticleParticle and fibre toxicology2020
Is aggregated synthetic amorphous silica toxicologically relevant?
Article in Particle and fibre toxicology, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 12 papers, 1 of them a synthesis that pooled it.
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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Who cites it
12 citing papers in PubMed, 1 synthesis or guideline pooled it.
- The Size-dependent Cytotoxicity of Amorphous Silica Nanoparticles: A Systematic Review of in vitro Studies.International journal of nanomedicine · 2020Pooled it
- Nanotoxicity of Porous Silica Nanoparticles: Physicochemical Properties and Mechanistic Cellular Endpoints.Nanomaterials (Basel, Switzerland) · 2025Review
- Colloidal Interactions in Simulated Intestinal Fluids: Implications for Oral Drug Delivery at the Nanoscale.Small science · 2025Article
- Impact of Milk on the Behavior and Toxicity of Nanosized SiOACS omega · 2025Article
- Adverse Outcome Pathways (AOPs) Oriented Approach to Assess In Vitro Hazard of Silica and Lignin Nanomaterials Derived from Biomass Residues.Nanomaterials (Basel, Switzerland) · 2025Article
- Synthetic amorphous silica: MAK Value Documentation, addendum - Translation of the German version from 2023.The MAK collection for occupational health and safety · 2025Review
- Humanising nanotoxicology: replacement of animal-derived products in the application of integrated approaches to testing and assessment of nanomaterial inhalation hazard.Frontiers in bioengineering and biotechnology · 2025Article
- About the Transient Effects of Synthetic Amorphous Silica: An In Vitro Study on Macrophages.International journal of molecular sciences · 2022Article
- Pulmonary Toxicity of Silica Linked to Its Micro- or Nanometric Particle Size and Crystal Structure: A Review.Nanomaterials (Basel, Switzerland) · 2022Review
- The TLR4/NFκB-Dependent Inflammatory Response Activated by LPS Is Inhibited in Human Macrophages Pre-Exposed to Amorphous Silica Nanoparticles.Nanomaterials (Basel, Switzerland) · 2022Article
- Assessing the Toxicological Relevance of Nanomaterial Agglomerates and Aggregates Using Realistic Exposure In Vitro.Nanomaterials (Basel, Switzerland) · 2021Article
- Pyrogenic and Precipitated Amorphous Silica Nanoparticles Differentially Affect Cell Responses to LPS in Human Macrophages.Nanomaterials (Basel, Switzerland) · 2020Article
Corrections and comments
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Authors and funding
11 authors.
Funding
Abstract
backgroundThe regulatory definition(s) of nanomaterials (NMs) frequently uses the term 'agglomerates and aggregates' (AA) despite the paucity of evidence that AA are significantly relevant from a nanotoxicological perspective. This knowledge gap greatly affects the safety assessment and regulation of NMs, such as synthetic amorphous silica (SAS). SAS is used in a large panel of industrial applications. They are primarily produced as nano-sized particles (1-100 nm in diameter) and considered safe as they form large aggregates (> 100 nm) during the production process. So far, it is indeed believed that large aggregates represent a weaker hazard compared to their nano counterpart. Thus, we assessed the impact of SAS aggregation on in vitro cytotoxicity/biological activity to address the toxicological relevance of aggregates of different sizes.
resultsWe used a precipitated SAS dispersed by different methods, generating 4 ad-hoc suspensions with different aggregate size distributions. Their effect on cell metabolic activity, cell viability, epithelial barrier integrity, total glutathione content and, IL-8 and IL-6 secretion were investigated after 24 h exposure in human bronchial epithelial (HBE), colon epithelial (Caco2) and monocytic cells (THP-1). We observed that the de-aggregated suspension (DE-AGGR), predominantly composed of nano-sized aggregates, induced stronger effects in all the cell lines than the aggregated suspension (AGGR). We then compared DE-AGGR with 2 suspensions fractionated from AGGR: the precipitated fraction (PREC) and the supernatant fraction (SuperN). Very large aggregates in PREC were found to be the least cytotoxic/biologically active compared to other suspensions. SuperN, which contains aggregates larger in size (> 100 nm) than in DE-AGGR but smaller than PREC, exhibited similar activity as DE-AGGR.
conclusionOverall, aggregation resulted in reduced toxicological activity of SAS. However, when comparing aggregates of different sizes, it appeared that aggregates > 100 nm were not necessarily less cytotoxic than their nano-sized counterparts. This study suggests that aggregates of SAS are toxicologically relevant for the definition of NMs.
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