10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
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Characterization of Nanoparticle Containing Formulations before and after Spraying on Textile Surfaces: The Influence of Surface Active Substances on Aerosol Formation Relevant for Inhalation
FRANK BIERKANDT, Sandra Wagener, Jutta Tentschert, Harald Jungnickel, Peter Laux, Andreas Luch, Lars Hillemann, Paul Bergelt, Federal Institute for Risk Assessment (BfR)
Abstract Number: 1721 Working Group: Aerosol Exposure
Abstract The growing application of engineered nanomaterials (ENM) and especially the use as constituents in numerous spray products (e.g., cosmetics, coating or cleaning products) increase the possibility of human exposure via inhalation. A detailed investigation of their behavior and toxic potential is therefore necessary. Adverse effects associated with aerosol inhalation are connected to the size and shape of ENM (e.g., rod-like particles) - amongst others - as these factors influence accessibility within the lungs. Moreover, the composition of the sprayed formulation and the resulting aerosol can also impact the toxicity as compounds adsorbed on any ENM may alter its properties as e.g. cellular uptake or reactivity. Also, certain formulations may carry substances into areas which are normally inaccessible (i.e., Trojan Horse effect). Thus, characterization of spray formulations and their influence on the fate of ENMs in solution as well as after aerosolization is essential and shall be addressed in this work. In addition to this, the alteration of the ENMs upon uptake in cellular systems will be investigated, combined with toxicity testing.
The emulated spray formulations - based on pure water and ethanol - contain Ag- and CeO2-ENMs in combination with several additives. These particles were selected because of their frequent use based on their bactericide activity (Ag-ENMs) or their UV-stability (CeO2-ENM). They also represent two groups of ENMs with different solubility: while Ag-ENMs are more soluble, CeO2-ENMs are considered rather insoluble and biodurable. To address nanoscale effects, respirable ENM sizes of < 100 nm, ~ 200 nm in addition to microsized particles were tested. Because surface active substances are sometimes used to alter the spray behavior, the influence of two perfluorinated silanoles on the ENM toxicity is being tested exemplarily.
The mentioned formulations were analyzed in regard to any alterations on the ENM characteristics before aerosolization and also after spraying onto textiles in order to simulate an impregnation process. Single particle inductively-coupled plasma mass spectrometry (spICPMS) and dynamic light scattering (DLS) were used for analysis in solution. For analysis of sprayed samples, time-of-flight secondary ion mass spectrometry (ToF-SIMS) as well as laser ablation (LA)-ICP-MS were applied.
First results indicate alterations induced in the ENM characteristics regarding size distribution and their dispersion stability by the different formulations. Time-resolved sp-ICP-MS analysis shows decreasing NP sizes for some ENM-formulations.
Using LA-ICP-MS of sprayed textiles, a distinction between different pre-treatments of textile samples could be seen in regard to ENM agglomeration after aerosol application onto these textiles. Using ToF-SIMS analysis penetration depth of applied ENMs to about 1 µm into the textile could be proofed and an aggregation size between 100 nm and 1 µm was recorded whereas the ENMs emitted from the source were sized below 100 nm.
This work is supported by SIINN ERA-NET, which is funded under the ERA-NET scheme of the Seventh Framework Program of the European Commission, Research Directorate - General, Grant Agreement No. 265799, and the German Federal Ministry of Education and Research.