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

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.

Nanosafety research in Europe - Towards a focus on nano-enabled products.

In the nanosafety projects funded by the European Commission a large amount of data has been generated on hazard and exposure for a variety of engineered nanomaterials (ENMs) and nano-enabled products (NEPs). However, not all the data generated has been published, nor has all the data been stored in an organised manner (e. g. database) which makes it very difficult for researchers, industry and other stakeholders to use it. This paper provides an inventory of NEPs studied in each of these projects, including relevant information on the NEPs, the life-cycle stages evaluated for each of them and an overview of the projects, which can be used for identifying areas in which there might be data gaps. The purpose of analyzing the nanosafety research done on NEPs was to provide an overview of the products studied compare to what can realistically be found in the market (i.e. the exposure relevant materials that workers, consumers and the environment may be exposed to). The analysis done in all the projects included in the inventory allowed the identification of the need to increase the number of studies with well-established commercialized NEPs, such as ENMs used in tyres or sunscreens. In addition, it was found that, in general, there was a correlation of the different ENMs studied with their respective production relevance (i.e. production volumes), except for silver, which was vastly over-represented, and on the other hand carbon black, which was under-represented. Addittionally, there is a need to improve accessibility to relevant and high quality data produced in all these projects to provide transparency and support to different stakeholder needs.