A 90-day oral exposure to food-grade gold at relevant human doses impacts the gut microbiota and the local immune system in a sex-dependent manner in mice.

Background: Edible gold (Au) is commonly used as a food additive (E175 in EU) for confectionery and cake decorations, coatings and in beverages. Food-grade gold is most often composed of thin Au sheets or flakes exhibiting micro- and nanometric dimensions in their thickness. Concerns about the impact of mineral particles used as food additives on human health are increasing with respect to the particular physico-chemical properties of nanosized particles, which enable them to cross biological barriers and interact with various body cell compartments.

Food-grade titanium dioxide translocates across the buccal mucosa in pigs and induces genotoxicity in an model of human oral epithelium.

The whitening and opacifying agent titanium dioxide (TiO) is used worldwide in various foodstuffs, toothpastes and pharmaceutical tablets. Its use as a food additive (E171 in EU) has raised concerns for human health. Although the buccal mucosa is the first area exposed, oral transmucosal passage of TiO particles has not been documented.

Influence of electron landing energy on the measurement of the dimensional properties of nanoparticle populations imaged by SEM.

Scanning Electron Microscopy (SEM) technique is widely used to characterize nanoparticle (NP) size. The landing energy (LE) of the primary electron beam is considered to be a key parameter related to the ability of electrons to penetrate the sample. However, few studies have been carried out so far on the influence of this parameter on the measurement of NP size by SEM.

Basal Ti level in the human placenta and meconium and evidence of a materno-foetal transfer of food-grade TiO nanoparticles in an ex vivo placental perfusion model.

Background: Titanium dioxide (TiO) is broadly used in common consumer goods, including as a food additive (E171 in Europe) for colouring and opacifying properties. The E171 additive contains TiO nanoparticles (NPs), part of them being absorbed in the intestine and accumulated in several systemic organs. Exposure to TiO-NPs in rodents during pregnancy resulted in alteration of placental functions and a materno-foetal transfer of NPs, both with toxic effects on the foetus.

A new method for measuring nanoparticle diameter from a set of SEM images using a remarkable point.

Scanning Electron Microscopy (SEM) is considered as a reference technique for the determination of nanoparticle (NP) dimensional properties. Nevertheless, the image analysis is a critical step of SEM measuring process and the initial segmentation phase consisting in determining the contour of each nano-object to be measured must be correctly carried out in order to identify all pixels belonging to it. Several techniques can be applied to extract NP from SEM images and evaluate their diameter like thresholding or watershed.