Effects of prenatal exposure to surface-coated nanosized titanium dioxide (UV-Titan). A study in mice

<p>Abstract</p> <p>Background</p> <p>Engineered nanoparticles are smaller than 100 nm and designed to improve or achieve new physico-chemical properties. Consequently, also toxicological properties may change compared to the parent compound. We examined developmental and neurobehavioral effects following maternal exposure to a nanoparticulate UV-filter (UV-titan L181).</p> <p>Methods</p> <p>Time-mated mice (C57BL/6BomTac) were exposed by inhalation 1h/day to 42 mg/m³aerosolized powder (1.7·10⁶n/cm³; peak-size: 97 nm) on gestation days 8-18. Endpoints included: maternal lung inflammation; gestational and litter parameters; offspring neurofunction and fertility. Physicochemical particle properties were determined to provide information on specific exposure and deposition.</p> <p>Results</p> <p>Particles consisted of mainly elongated rutile titanium dioxide (TiO₂) with an average crystallite size of 21 nm, modified with Al, Si and Zr, and coated with polyalcohols. In exposed adult mice, 38 mg Ti/kg was detected in the lungs on day 5 and differential cell counts of bronchoalveolar lavage fluid revealed lung inflammation 5 and 26-27 days following exposure termination, relative to control mice. As young adults, prenatally exposed offspring tended to avoid the central zone of the open field and exposed female offspring displayed enhanced prepulse inhibition. Cognitive function was unaffected (Morris water maze test).</p> <p>Conclusion</p> <p>Inhalation exposure to nano-sized UV Titan dusts induced long term lung inflammation in time-mated adult female mice. Gestationally exposed offspring displayed moderate neurobehavioral alterations. The results are discussed in the light of the observed particle size distribution in the exposure atmosphere and the potential pathways by which nanoparticles may impart changes in fetal development.</p

Bioaccumulation and ecotoxicity of carbon nanotubes

Carbon nanotubes (CNT) have numerous industrial applications and may be released to the environment. In the aquatic environment, pristine or functionalized CNT have different dispersion behavior, potentially leading to different risks of exposure along the water column. Data included in this review indicate that CNT do not cross biological barriers readily. When internalized, only a minimal fraction of CNT translocate into organism body compartments. The reported CNT toxicity depends on exposure conditions, model organism, CNT-type, dispersion state and concentration. In the ecotoxicological tests, the aquatic organisms were generally found to be more sensitive than terrestrial organisms. Invertebrates were more sensitive than vertebrates. Single-walled CNT were found to be more toxic than double-/multi-walled CNT. Generally, the effect concentrations documented in literature were above current modeled average environmental concentrations. Measurement data are needed for estimation of environmental no-effect concentrations. Future studies with benchmark materials are needed to generate comparable results. Studies have to include better characterization of the starting materials, of the dispersions and of the biological fate, to obtain better knowledge of the exposure/effect relationships

In vitro assessment of engineered nanomaterials using a hepatocyte cell line: cytotoxicity, pro-inflammatory cytokines and functional markers.

Effects on the liver C3A cell line treated with a panel of engineered nanomaterials (NMs) consisting of two zinc oxide particles (ZnO; coated 100 nm and uncoated 130 nm), two multi-walled carbon nanotubes (MWCNTs), one silver (Ag < 20 nm), one 7 nm anatase, two rutile TiO2 nanoparticles (10 and 94 nm) and two derivatives with positive and negative covalent functionalisation of the 10 nm rutile were evaluated. The silver particles elicited the greatest level of cytotoxicity (24 h LC50 – 2 µg/cm2). The silver was followed by the uncoated ZnO (24 h LC50 – 7.5 µg/cm2) and coated ZnO (24 h LC50 – 15 µg/cm2) particles with respect to cytotoxicity. The ZnO NMs were found to be about 50–60% soluble which could account for their toxicity. By contrast, the Ag wa

UV exposure on a single-mode fiber within a multimode interference structure

We experimentally study the effects of UV exposure on a single-mode fiber (SMF) with a fiber multimode interferometer (MMI) based on the singlemode-multimode-singlemode-multimode-singlemode (SMSMS) fiber structure. We observe a wavelength shift of over 33 nm when irradiating the central SMF in the SMSMS fiber structure with a 3-mm-width UV beam (the UV laser has a wavelength of 193 nm and pulse energy of 3 mJ). According to our numerical simulation, the SMSMS fiber structure can achieve a very high refractive-index (RI) sensitivity of 67670 nm/RIU with a very good linearity o

Transcriptional profiling identifies physicochemical properties of nanomaterials that are determinants of the in vivo pulmonary response.

We applied transcriptional profiling to elucidate the mechanisms associated with pulmonary responses to titanium dioxide (TiO2) nanoparticles (NPs) of different sizes and surface coatings, and to determine if these responses are modified by NP size, surface area, surface modification and embedding in paint matrices. Adult C57BL/6 mice were exposed via single intratracheal instillations to free forms of TiO2NPs (10 nm, 20.6 nm or 38 nm in diameter) with different surface coatings, or TiO2NPs embedded in paint matrices. Controls were exposed to dispersion medium devoid of NPs. TiO2NPs were characterized for size, surface area, chemical impurities and agglomeration state in the exposure medium. Pulmonary transcriptional profiles were generated using microarrays from tissues collected one and 28 d post-exposure. Property-specific pathway effects were identified. Pulmonary protein levels of specific inflammatory cytokines and chemokines were confirmed by ELISA. The data were collapsed to 659 differentially expressed genes (P ≤ 0.05; fold change ≥ 1.5). Unsupervised hierarchical clustering of these genes revealed that TiO2NPs clustered mainly by post-exposure timepoint followed by particle type. A pathway-based meta-analysis showed that the combination of smaller size, large deposited surface area and surface amidation contributes to TiO2NP gene expression response. Embedding of TiO2NP in paint dampens the overall transcriptional effects. The magnitude of the expression changes associated with pulmonary inflammation differed across all particles; however, the underlying pathway perturbations leading to inflammation were similar, suggesting a generalized mechanism-of-action for all TiO2NPs. Thus, transcriptional profiling is an effective tool to determine the property-specific biological/toxicity responses induced by nanomaterials.JRC.H.6-Digital Earth and Reference Dat