Project R-11334

Nathalie Leynen: Does size matter? A study on the in vivo effects of inorganic and organic nanoparticles in Schmidtea mediterranea (Research)

Nanoparticles (NPs) are ubiquitous in the environment, originating from natural or anthropogenic sources. Natural NPs are produced through natural processes, including forest fires, volcanic ash, dust storms and biological particles such as bacteria and fungi. NPs from anthropogenic sources are a result of human-related activities or processes, such as combustion and the use of products containing NPs. As the particle size decreases, the surface area increases, resulting in a higher proportion of atoms on the particle surface. This leads to increased chemical reactivity and hence material efficiency, which explains its economically attractive nature. The increased reactivity and efficiency of NPs can also be negative in terms of their toxic potential. The physicochemical characteristics of NPs are completely different from those of bulk material. Despite the ever-increasing production of NPs, the potential safety hazards of these particles to organs, tissues and cells are still not fully understood. The large variation in these characteristics makes it difficult to generalize the effects of NPs on organisms or cells. Many earlier technologies, such as fossil fuels, asbestos, or DDT have been perceived to be safe for society and the environment. These historical mistakes show how crucial it is to investigate the potentially toxic effects of NPs in-depth before they are spread across ecosystems. This thesis aims to contribute to knowledge on the toxicity of three metal (oxide) NPs and one organic NP that are abundantly used and/or present in the environment: silver NPs, titanium dioxide NPs, silica NPs and nanoplastics. The main objectives of this thesis are (1) To study uptake and distribution of NPs in planarians at the tissue and subcellular level. (2) To assess if developing organisms are at higher risk compared to homeostatic organisms. (3) To determine if effects vary, based on the used NP concentrations. (4) To understand if NP coating or sizes are important aspects of their toxicity. And finally, (5) to hypothesize on the underlying mechanisms of NP toxicity, based on all acquired data

01 October 2020 - 31 December 2020