InnoMat.Life developed for all selected material classes grouping approaches, formulated grouping hypotheses and selected appropriate grouping criteria. They have been tested with selected materials. The following results were achieved.
(Nano-)fibresThe fibre paradigm describes a well established morphological paradigm. Nanofibres are challenging this paradigm. Thin nanofibres can coil up and don't show a characteristic fibre of action. Currently, animal studies are needed for regulatory testing. Most of the previous projects investigated carbon nanotubes (CNTs). InnoMat.Life was the first to investigate a broad selection of fibres, including various nanofibres. The
BfRshort forGerman Federal Institute for Risk Assessment contributed with proteomic investigations. Profound changes in the proteom of cells could be detected. InnoMat.Life delivered important contributions to the establishment of a fibre testing and assessment strategy.
Polydisperse polymer particles for additive manufacturing (3D printing)Many polymers are considered biocompatible and can be assessed as a group following the OECD polymer of low concern concept. To which extent this concept can be applied to polymeric particles and which criteria have to be considered in that case was not clear at the project start. InnoMat.Life focused on polymer particles for additive manufacturing but the results are also useful for assessing particles from the environment, so-called micro- and nanoplastics. Many of the previous studies focused on polystyrene particles while InnoMat.Life was the first to assess a broad selection of different polymer particles in a systematic manner.The experimental work at the
BfRshort forGerman Federal Institute for Risk Assessment focused on investigating the carrier hypothesis, according to which the polymer particles can act as a vehicle for environmental pollutants. At the
BfRshort forGerman Federal Institute for Risk Assessment firstly a novel analysis method was established, which allowed for an indirect evaluation of the sorption of polycyclic aromatic hydrocarbons (PAHs) to polymer particles (passive third-phase partitioning method). Using this method 17 polymer variants were studied. Sorption was mainly depended on the polymer type but further influenced by other particle properties such as e.g. particle size. Furthermore, the desorption into different
in vitro digestion simulant fluids was characterized at the
BfRshort forGerman Federal Institute for Risk Assessment. It was shown that a significant amount of the sorbed-PAHs can be desorbed from the polymer particles. In addition, extensive
in vitro investigations to characterize the carrier hypothesis were conducted at the
BfRshort forGerman Federal Institute for Risk Assessment. In a screening all the polymer particles showed no cytotoxic effect and no intrinsic particle reactivity. The carrier effect was investigated using benzo-[a]-pyrene loaded PA-6 particles in CaCo-2 cells. A carrier effect was detectable but was very low. If cells were treated with a similar amount of B[a]
Pshort forphosphorus alone or in co-exposure to particles without prior loading the effects were much higher.Several useful methods could be established. The extensive investigations also delivered an important contribution to the risk assessment of micro- and nanoplastics.
Materials with complex composition and/or morphologyThis material class was the most challenging. At the
BfRshort forGerman Federal Institute for Risk Assessment no experimental work was conducted with the selected materials. The
BfRshort forGerman Federal Institute for Risk Assessment, however, contributed to the conceptional work and with their presentation to expert panels (e.g. OECD WPMN). Follow-up projects such as the EU project HARMLESS will build on these results.Overall, InnoMat.Life delivered an important contribution to the risk assessment of all selected innovative materials.