Researchers from Institut national de la recherche agronomique (Inra) and their partners, of which the Luxembourg Institute of Science and Technology (LIST) have studied the effects of oral exposure to titanium dioxide, an additive (E171) commonly used in foodstuffs, especially confectionary. They have shown for the first time that E171 crosses the intestinal barrier in animals and reaches other parts of the body. Immune system disorders linked to the absorption of the nanoscale fraction of E171 particles were observed. The researchers also showed that chronic oral exposure to the additive spontaneously induced preneoplastic lesions in the colon, a non-malignant stage of carcinogenesis, in 40% of exposed animals. Moreover, E171 was found to accelerate the development of lesions previously induced for experimental purposes. While the findings show that the additive plays a role in initiating and promoting the early stages of colorectal carcinogenesis, they cannot be extrapolated to humans or more advanced stages of the disease. The findings were published in the 20 January 2017 issue of Scientific Reports. The findings were published in the 20 January 2017 issue of Scientific Reports. (See the full press release on the Inra website).
In order to successfully complete this study, Inra made particular use of LIST's cutting-edge toxicological microanalysis know-how. The toxicology study coupled with ion microscopy technology, an ultra-high-resolution imaging system, carried out at LIST is not only unique in Luxembourg but also very little developed around the world. This type of analysis can be also conducted for other environmental, cosmetic or pharmacological applications.
Using samples sent by Inra, LIST's secondary ion mass spectrometry (SIMS) experts were able to detect and locate traces of E171 nanoparticles in biological surfaces, especially in the small intestine and the colon. In particular, these traces have been found lodged in immune cell nuclei in Peyer's patches. On the basis of these investigations carried out by means of SIMS imaging by LIST researchers and corroborated by other analysis techniques such as those obtained on the SOLEIL synchrotron, Inra was able to demonstrate for the first time that the E171 food and cosmetics additive affects the immune functions and the development of preneoplastic lesions in the colon.
Meeting European expectations with its involvement in this study, LIST is fully in line with the European goal of studying the future of nanoparticles in our environment. The results obtained during this work will in fact be followed up in the recently launched European project funded under the H2020 programme, "The nanoparticle-scope: a new integrated instrument for accurate and reproducible physico-chemical characterisation of nanoparticles" npSCOPE.
Coordinated by LIST, the purpose of this project is to develop a new integrated tool, optimised to provide a full physical-chemical description of the nanoparticles, both in their primitive form and incorporated in complex matrices such as biological tissues.
>> See the study published in Scientific Reports on the Nature publications website
>> Read also the article published in Le Monde "Alerte sur les dangers du dioxyde de titane E171, un additif alimentaire très courant" on 20.01.2017.
photography : in red, the localisation of titanium in Peyer's cells