Publications by authors named "Jo Van Laer"

5 Publications

  • Page 1 of 1

An in vitro air-liquid interface inhalation platform for petroleum substances and constituents.

ALTEX 2021 04 20. Epub 2021 Apr 20.

VITO NV (Flemish Institute for Technological Research), Unit HEALTH, Mol, Belgium.

The goal is to optimize and show the validity of an in vitro method for inhalation testing of petroleum substances and its constituents at the air-liquid interface (ALI). The approach is demonstrated in a pilot study with ethylbenzene (EB), a mono-constituent petroleum substance using a human alveolar epithelial cell line model. This included the development and validation of a generation facility to obtain EB vapors and the optimization of an exposure system for a negative control (clean air, CA), positive control (nitrogen dioxide), and EB vapors. The optimal settings for the VITROCELL® 24/48 system were defined. Cytotoxicity, cell viability, inflammation, and oxidative stress were assessed in A549 after exposure to EB vapors. A concentration-dependent significant decrease in mean cell viability was observed after exposure, which was confirmed by a cytotoxicity test. The oxidative stress marker superoxide dismutase 2 was significantly increased, but no concentration-response was observed. A concentration-dependent significant increase in pro-inflammatory markers C-C motif chemokine ligand 2, interleukin (IL)6, and IL8 was observed for EB-exposed A549 cells compared to CA. The data demonstrated consistency between in vivo air concentrations at which adverse respiratory effects were observed and ALI-concentrations affecting cell viability, provided that the actual measured in vitro delivery efficiency of the compound were included. It can be concluded that extrapolating in vitro air concentrations (adjusted for delivery efficiency and absorption characteristics and applied for testing cell viability) to simulate in vivo air concentrations may be a promising method to screen for acute inhalation toxicity.
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http://dx.doi.org/10.14573/altex.2010211DOI Listing
April 2021

Release and cytotoxicity screening of the printer emissions of a CdTe quantum dots-based fluorescent ink.

Toxicol Lett 2021 Apr 18;347:1-11. Epub 2021 Apr 18.

LEITAT Technological Center, Carrer de la Innovació 2, 08225, Terrassa, Barcelona, Spain. Electronic address:

The fluorescent properties of cadmium telluride (CdTe) containing quantum dots (QDs) have led to novel products and applications in the ink and pigment industry. The toxic effects of the emissions associated to the use of printing ink containing CdTe QDs might differ from those of conventional formulations which do not integrate nanoparticles, as CdTe QDs might be emitted. Within this work, the airborne emissions of a water-soluble fluorescent ink containing polyethylene glycol (PEG)-coated CdTe QDs of 3-5 nm diameter have been characterized and studied under controlled conditions during household inkjet printing in a scenario simulating the use phase. Subsequently, the cytotoxicological potential of atomized CdTe QDs ink in an acute exposure regimen simulating an accidental, worse-case scenario has been evaluated in vitro at the air-liquid interface (ALI) using the pulmonary cell line BEAS-2B. Endpoints screened included cell viability, oxidative stress and inflammatory effects. We have observed that CdTe QDs ink at 54.7 ng/mL decreased cell viability by 25.6 % when compared with clean air after 1h of exposure; a concentration about 65 times higher was needed to observe a similar effect in submerged conditions. However, we did not observe oxidative stress or inflammatory effects. The present study integrates the development of scenarios simulating the use phase of nano-additivated inks and the direct cell exposure for in vitro effects assessment, thus implementing a life-cycle oriented approach in the assessment of the toxicity of CdTe QDs.
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http://dx.doi.org/10.1016/j.toxlet.2021.04.009DOI Listing
April 2021

Alternative air-liquid interface method for inhalation toxicity testing of a petroleum-derived substance.

MethodsX 2020 8;7:101088. Epub 2020 Oct 8.

VITO NV (Flemish Institute for Technological Research), Unit HEALTH, Mol, Belgium.

-based new approach methodologies (NAMs) provide a pragmatic solution to animal testing of petroleum substances and their constituents. A previous study exposed an in vitro model (A549 cells) at the air-liquid interface (ALI) to assess inhalation toxicity of a single compound, ethylbenzene. Experimental conditions using VITROCELL 24/48 exposure system were optimized to achieve a deposition efficiency that resulted in dose-dependent biological changes. The feasibility of this set-up was evaluated for testing the complex substance gasoline, which, at only high concentrations, can induce mild respiratory irritation in animals and cough in humans.•Results showed that perpendicular ALI exposure flow systems (VITROCELL® 6/4 and 24/48) may not be appropriate for testing gasoline because it was not possible to achieve enough deposition onto the cells and in the culture medium to measure dose and to determine dose-dependent biological changes (more information can be found in 'Supplementary material and/or Additional information' section).•Structural features ( aromatic or saturated hydrocarbon structure) and high hydrophobicity, together with the low concentrations of individual components in gasoline, may have caused the low deposition.•To achieve a higher deposition on the cells, A549 cells were exposed to gasoline at the ALI by passive dosing.The results demonstrate that the presented methodology is a promising NAM for inhalation toxicity testing of (semi-)volatile complex substances with low aqueous solubility.
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http://dx.doi.org/10.1016/j.mex.2020.101088DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7581970PMC
October 2020

Assessment of nanoparticles release into the environment during drilling of carbon nanotubes/epoxy and carbon nanofibres/epoxy nanocomposites.

J Hazard Mater 2017 Oct 27;340:57-66. Epub 2017 Jun 27.

Centre for Advanced Engineering Materials, School of Engineering, Robert Gordon University, Aberdeen, AB10 7GJ, United Kingdom. Electronic address:

The risk assessment, exposure and understanding of the release of embedded carbon nanotubes (CNTs) and carbon nanofibers (CNFs) from commercial high performance composites during machining processes are yet to be fully evaluated and quantified. In this study, CNTs and CNFs were dispersed in epoxy matrix through calendaring process to form nanocomposites. The automated drilling was carried out in a specially designed drilling chamber that allowed elimination of background noise from the measurements. Emission measurements were taken using condensed particle counter (CPC), scanning mobility particle sizer (SMPS) and DMS50 Fast Particulate Size Spectrometer. In comparison to the neat epoxy, the study results revealed that the nano-filled samples produced an increase of 102% and 227% for the EP/CNF and EP/CNT sample respectively in average particle number concentration emission. The particle mass concentration indicated that the EP/CNT and EP/CNF samples released demands a vital new perspective on CNTs and CNFs embedded within nanocomposite materials to be considered and evaluated for occupational exposure assessment. Importantly, the increased concentration observed at 10nm aerosol particle sizes measurements strongly suggest that there are independent CNTs being released at this range.
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http://dx.doi.org/10.1016/j.jhazmat.2017.06.057DOI Listing
October 2017

A Novel Exposure System Termed NAVETTA for In Vitro Laminar Flow Electrodeposition of Nanoaerosol and Evaluation of Immune Effects in Human Lung Reporter Cells.

Environ Sci Technol 2017 May 14;51(9):5259-5269. Epub 2017 Apr 14.

Paris Lodron University of Salzburg (PLUS) , Department of Molecular Biology, Hellbrunnerstrasse 34, 5020 Salzburg, Austria.

A new prototype air-liquid interface (ALI) exposure system, a flatbed aerosol exposure chamber termed NAVETTA, was developed to investigate deposition of engineered nanoparticles (NPs) on cultured human lung A549 cells directly from the gas phase. This device mimics human lung cell exposure to NPs due to a low horizontal gas flow combined with cells exposed at the ALI. Electrostatic field assistance is applied to improve NP deposition efficiency. As proof-of-principle, cell viability and immune responses after short-term exposure to nanocopper oxide (CuO)-aerosol were determined. We found that, due to the laminar aerosol flow and a specific orientation of inverted transwells, much higher deposition rates were obtained compared to the normal ALI setup. Cellular responses were monitored with postexposure incubation in submerged conditions, revealing CuO dissolution in a concentration-dependent manner. Cytotoxicity was the result of ionic and nonionic Cu fractions. Using the optimized inverted ALI/postincubation procedure, pro-inflammatory immune responses, in terms of interleukin (IL)-8 promoter and nuclear factor kappa B (NFκB) activity, were observed within short time, i.e. One hour exposure to ALI-deposited CuO-NPs and 2.5 h postincubation. NAVETTA is a novel option for mimicking human lung cell exposure to NPs, complementing existing ALI systems.
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http://dx.doi.org/10.1021/acs.est.7b00493DOI Listing
May 2017