Baun, Anders

Jensen, Amalie Thit

Jensen, Louise Helene Søgaard

Købler, Carsten

Mølhave, Kristian

Skjolding, Lars Michael

Sørensen, Sara Nørgaard

Online Research Database In Technology

                       General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.  • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal   If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.     Downloaded from orbit.dtu.dk on: Dec 20, 2017Localization and analysis of engineered nanoparticles in Daphnia MagnaJensen, Louise Helene Søgaard; Sørensen, Sara Nørgaard; Jensen, Amalie Thit; Skjolding, Lars Michael;Købler, Carsten; Mølhave, Kristian; Baun, AndersPublication date:2014Link back to DTU OrbitCitation (APA):Jensen, L. H. S., Sørensen, S. N., Jensen, A. T., Skjolding, L. M., Købler, C., Mølhave, K., & Baun, A. (2014).Localization and analysis of engineered nanoparticles in Daphnia Magna. Abstract from 18th InternationalMicroscopy Congress 2014, Prague, Czech Republic.Localization and analysis of engineered nanoparticles in Daphnia Magna  Engineered nanoparticles are added to a growing amount of consumer products and are considered the fastest growing nanotechnology product. They are being washed out into the waste water systems in potentially increasing amounts as the use and number of products that contain nanoparticles is expanding. There are concerns that they could be harmful to aquatic organisms in nature. The uptake mechanisms in aquatic organisms are therefore important to elucidate the toxic mechanisms. Previous results have indicated that gold nanoparticles to a limited extent are able to pass the peritrophic membrane and in some cases enter the gut epithelial cells in the freshwater crustacean Daphnia magna (ref1). In the absence of food, the amount of gold nanoparticles is elevated compared to when the animal is feeding. It has been speculated that when gold nanoparticles are present in the gut in relatively high amounts they might be able to cross the peritropic or cell membrane during the preparation for electron microscopy, perhaps during the epon infiltration step. In the present study D. magna were exposed for 24h to 0.4 mg Au/L citrate coated gold nanoparticles (10 nm) without food and an additional control was added to the experiment; D. magna which were exposed to gold nanoparticles during the infiltration process for electron microscopy. The uptake into gut lumen and internalization into epithelial cells of exposed D. magna was examined by light microscopy, TEM, FIB-SEM and EDX. The bulk of the gold nanoparticles in the exposed animals was observed as both single nanoparticles and aggregates located in the gut lumen while relatively few gold nanoparticles were observed across the peritrophic membrane associated with the microvilli. This is indicating that the peritrophic membrane of the gut in D. magna is able to form a barrier of low permeability to the gold nanoparticles in all cases. Very few gold nanoparticles were found to be internalized by the gut epithelial cells. The results suggest that 10 nm gold nanoparticles are able pass the peritrophic membrane and enter the gut epithelial cells.     Ref1: Lars Michael Skjolding, Sara Nørgaard Sørensen, Amalie Thit, Carsten Købler, Kristian Mølhave, Anders Baun. Uptake of gold nanoparticle in Daphnia magna gut in the presence and absence of food using electron microscopy. To be presented at SETAC Europe 24th Annual Meeting, May 2014. Acknowledgements: Micrographs were recorded at Core Facility for Integrative Microscopy, Copenhagen University and Center for Electron Nanoscopy, Technical University of Denmark.      

Localization and analysis of engineered nanoparticles in Daphnia Magna

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Localization and analysis of engineered nanoparticles in Daphnia Magna

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