Publications by authors named "Hélène Terrisse"

6 Publications

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digestion of food grade TiO (E171) and TiO nanoparticles: physicochemical characterization and impact on the activity of digestive enzymes.

Food Funct 2021 Jul;12(13):5975-5988

INRAE, UR1268 Biopolymères Interactions Assemblages, 44300 Nantes, France.

Titanium dioxide is a food additive that has raised some concerns for humans due to the presence of nanoparticles. We were interested in knowing the fate of TiO2 particles in the gastro-intestinal tract and their potential effect on digestive enzymes. For this purpose, we analysed the behaviour of two different food grade TiO2 samples (E171) and one nano-sized TiO2 sample (P25) through a standardized static in vitro digestion protocol simulating the oral, gastric and intestinal phases with appropriate juices including enzymes. Both E171 and P25 TiO2 particles remained intact in the digestive fluids but formed large agglomerates, and especially in the intestinal fluid where up to 500 μm sized particles have been identified. The formation of these agglomerates is mediated by the adsorption of mainly α-amylase and divalent cations. Pepsin was also identified to adsorb onto TiO2 particles but only in the case of silica-covered E171. In the salivary conditions, TiO2 exerted an inhibitory action on the enzymatic activity of α-amylase. The activity was reduced by a factor dependent on enzyme concentrations (up to 34% at 1 mg mL-1) but this inhibitory effect was reduced to hardly 10% in the intestinal fluid. In the gastric phase, pepsin was not affected by any form of TiO2. Our results hint that food grade TiO2 has a limited impact on the global digestion of carbohydrates and proteins. However, the reduced activity specifically observed in the oral phase deserves deeper investigation to prevent any adverse health effects related to the slowdown of carbohydrate metabolism.
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http://dx.doi.org/10.1039/d1fo00499aDOI Listing
July 2021

Repeated exposure of Caco-2 versus Caco-2/HT29-MTX intestinal cell models to (nano)silver in vitro: Comparison of two commercially available colloidal silver products.

Sci Total Environ 2021 Feb 17;754:142324. Epub 2020 Sep 17.

Toxalim, Université de Toulouse, INRAE, INP-ENVT, INP-EI-Purpan, Université de Toulouse 3 Paul Sabatier, Toulouse, France. Electronic address:

Colloidal silver products are sold for a wide range of disinfectant and health applications. This has increased the potential for human exposure to silver nanoparticles (AgNPs) and ions (Ag), for which oral ingestion is considered to be a major route of exposure. Our objective was to evaluate and compare the toxicity of two commercially available colloidal silver products on two human intestinal epithelial models under realistic exposure conditions. Mesosilver™ and AgC were characterized and a concentration range between 0.1 and 12 μg/mL chosen. Caco-2 cells vs. co-culture of Caco-2 and mucus-secreting HT29-MTX cells (90/10) were used. Repeated exposure was carried out to determine cell viability over 18 days of cell differentiation in 24-well plates. Selected concentrations (0.1, 1, and 3 μg/mL) were tested on cells cultured in E-plates and Transwells with the same repeated exposure regimen, to determine cell impedance, and cell viability and trans-epithelial electrical resistance (TEER), respectively. Silver uptake, intracellular localisation, and translocation were determined by CytoViva™, HIM-SIMS, and ICP-MS. Genotoxicity was determined on acutely-exposed proliferating Caco-2 cells by γH2AX immunofluorescence staining. Repeated exposure of a given concentration of AgC, which is composed solely of ionic silver, generally exerted more toxic effects on Caco-2 cells than Mesosilver™, which contains a mix of AgNPs and ionic silver. Due to its patchy structure, the presence of mucus in the Caco-2/HT29-MTX co-culture only slightly mitigated the deleterious effects on cell viability. Increased genotoxicity was observed for AgC on proliferating Caco-2 cells. Silver uptake, intracellular localisation, and translocation were similar. In conclusion, Mesosilver™ and AgC colloidal silver products show different levels of gut toxicity due to the forms of distinct silver (AgNPs and/or Ag) contained within. This study highlights the applicability of high-resolution (chemical) imaging to detect and localize silver and provides insights into its uptake mechanisms, intracellular fate and cellular effects.
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http://dx.doi.org/10.1016/j.scitotenv.2020.142324DOI Listing
February 2021

Evaluation of the content of TiO nanoparticles in the coatings of chewing gums.

Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2018 Feb 20;35(2):211-221. Epub 2017 Oct 20.

a UR1268 BIA (Biopolymères Interactions Assemblages), INRA , Nantes , France.

Titanium dioxide is a metal oxide used as a white pigment in many food categories, including confectionery. Due to differences in the mass fraction of nanoparticles contained in TiO, the estimated intakes of TiO nanoparticles differ by a factor of 10 in the literature. To resolve this problem, a better estimation of the mass of nanoparticles present in food products is needed. In this study, we focused our efforts on chewing gum, which is one of the food products contributing most to the intake of TiO. The coatings of four kinds of chewing gum, where the presence of TiO was confirmed by Raman spectroscopy, were extracted in aqueous phases. The extracts were analysed by transmission electron microscopy (TEM), X-ray diffraction, Fourier Transform Raman spectroscopy, and inductively coupled plasma atomic emission spectroscopy (ICP-AES) to establish their chemical composition, crystallinity and size distribution. The coatings of the four chewing gums differ chemically from each other, and more specifically the amount of TiO varies from one coating to another. TiO particles constitute the entire coating of some chewing gums, whereas for others, TiO particles are embedded in an organic matrix and/or mixed with minerals like calcium carbonate, talc, or magnesium silicate. We found 1.1 ± 0.3 to 17.3 ± 0.9 mg TiO particles per piece of chewing gum, with a mean diameter of 135 ± 42 nm. TiO nanoparticles account for 19 ± 4% of all particles, which represents a mass fraction of 4.2 ± 0.1% on average. The intake of nanoparticles is thus highly dependent on the kind of chewing gum, with an estimated range extending from 0.04 ± 0.01 to 0.81 ± 0.04 mg of nano-TiO per piece of chewing gum. These data should serve to refine the exposure scenario.
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http://dx.doi.org/10.1080/19440049.2017.1384576DOI Listing
February 2018

Silica nanofibers as a new drug delivery system: a study of the protein-silica interactions.

J Mater Chem B 2017 Apr 3;5(16):2908-2920. Epub 2017 Apr 3.

INSERM, UMRS 1229, RMeS "Regenerative Medicine and Skeleton", Team STEP "Physiopathology and joint regenerative medicine", Nantes, France.

Drug delivery systems are proposed for the in situ controlled delivery of therapeutic molecules in the scope of tissue engineering. We propose herein silica nanofibers as carriers for the loading and release of bioactive proteins. The influence of pH, time and concentration on the amount of adsorbed proteins was studied. The interactions allowing loading were then studied by means of electron microscopy, zeta potential measurements, electron energy loss spectroscopy and attenuated total reflectance Fourier transform infrared analysis. Release profiles were determined and biological activities were enzymatically assessed. The first part of the work was carried out with lysozyme as a model protein, and then bioactive growth factors TGF-β1 and GDF-5 were used because their significance in human adipose stromal cell differentiation towards intervertebral disc nucleopulpocytes was previously assessed. It is demonstrated that protein-silica nanofiber interactions are mainly driven by hydrogen bonds and local electrostatic interactions. The present data thus provide a better understanding of the adsorption phenomenon involved, as well as a method to control protein adsorption and release. It is worth pointing out that the kinetic release of growth factors, up to 28 days, and their biological activity maintenance seem to be compatible with intervertebral disc regenerative medicine.
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http://dx.doi.org/10.1039/c7tb00332cDOI Listing
April 2017

Criteria to define a more relevant reference sample of titanium dioxide in the context of food: a multiscale approach.

Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2017 May 14;34(5):653-665. Epub 2017 Feb 14.

a UR1268 BIA (Biopolymères Interactions Assemblages) , INRA , Nantes , France.

Titanium dioxide (TiO) is a transition metal oxide widely used as a white pigment in various applications, including food. Due to the classification of TiO nanoparticles by the International Agency for Research on Cancer as potentially harmful for humans by inhalation, the presence of nanoparticles in food products needed to be confirmed by a set of independent studies. Seven samples of food-grade TiO (E171) were extensively characterised for their size distribution, crystallinity and surface properties by the currently recommended methods. All investigated E171 samples contained a fraction of nanoparticles, however, below the threshold defining the labelling of nanomaterial. On the basis of these results and a statistical analysis, E171 food-grade TiO totally differs from the reference material P25, confirming the few published data on this kind of particle. Therefore, the reference material P25 does not appear to be the most suitable model to study the fate of food-grade TiO in the gastrointestinal tract. The criteria currently to obtain a representative food-grade sample of TiO are the following: (1) crystalline-phase anatase, (2) a powder with an isoelectric point very close to 4.1, (3) a fraction of nanoparticles comprised between 15% and 45%, and (4) a low specific surface area around 10 m g.
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http://dx.doi.org/10.1080/19440049.2017.1284346DOI Listing
May 2017

Interactions between phospholipids and titanium dioxide particles.

Colloids Surf B Biointerfaces 2014 Nov 16;123:150-7. Epub 2014 Sep 16.

Institut Matériaux Jean Rouxel IMN, UMR 6502, Univ Nantes, CNRS, F-44322 Nantes 3, France.

A systematic study was carried out on monolayer films and lipid vesicles to elucidate the interactions between membrane lipids and commercial particles of titanium dioxide TiO2 (TiO2-P25). Pressure-area isotherms of lipids at various pH values were recorded on a Langmuir trough with or without TiO2-P25 and NaCl in the subphase. Electrophoretic mobilities of lipid vesicles and TiO2-P25 particles were measured to identify the pH range where attractive electrostatic interactions between lipids and TiO2-P25 could take place. The results show that (i) the surface of TiO2-P25 particles interacts only with some phospholipids, (ii) the driving forces are electrostatic and (iii) non-electrostatic interactions were also observed, depending on the molecular structure. More precisely, the phospholipids 1,2-dimyristoyl-sn-glycero-3-phosphate monosodium salt (DMPA), 1,2-dimyristoyl-sn-glycero-3-phospho-rac-1-glycerol (DMPG) and 1',3'-bis[1,2-dimyristoyl-sn-glycero-3-phospho]-sn-glycerol (TMCL) interacted strongly with the TiO2-P25 surface through electrostatic interactions, providing they were oppositely charged, i.e. for pH between 2 and 6.6. For TMCL and DMPG, interactions with the surface of TiO2-P25 in non-favourable electrostatic conditions, suggested another kind of binding, probably through the hydroxyl groups of the terminal glycerol. Weaker attractive interactions were demonstrated for 1,2-dimyristoyl-sn-glycero-3-phospho-l-serine (DMPS) and the synthetic lipid dihexadecyl phosphate (DHP). For DMPS, the carboxylate group is involved in the adsorption onto TiO2. The other membrane lipids such as 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine (DMPE) and sphingomyelin (SM) did not interact with TiO2-P25 regardless of pH.
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http://dx.doi.org/10.1016/j.colsurfb.2014.09.010DOI Listing
November 2014
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