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ePaper created 2014-07-24, 14:56:51 | version 1.32.01
of large intracellular vesicles. Light and electron microscopy were applied to localize and correla- te fluorescence signals with the presence of gold cores. Implementation of mechanical strain in a cell culture model In conventional cell culture models used to inves- tigate the effects of nanoparticles on human cells, the cells are grown on more or less stiff surfaces. This neglects the fact that in their natural environ- ment most cells are exposed to mechanical stimu- li. Alveolar cells, for example, are subjected to a reversible stretch imposed by breathing. Mechanical stimuli of lung epithelial cells affect molecular processes as well as the formation and secretion of lung surfactant. Our investigations have shown that nanoparticles in living A549 cells are associa- ted with cellular structures involved in this secretion process. In the frame of a doctoral research stu- dy that started in 2013, the relation of mechanical strain and nanoparticle effects on surfactant secre- tion are studied in detail. As a start, the stretch model has been successfully established. “Nanosafety2013” One important activity of the Program Division Nano Cell Interactions (together with colleagues from the Program Division Optical Materials) was the organization of the Nanosafety 2013 conference. This successful event was hosted by INM in coope- ration with the “Leibniz Research Alliance Nano- safety” and is further described in the Highlight section. Focus projects In 2013, INM for the first time launched the INM focus project competition. The Program Division Nano Cell Interactions takes part in two initiatives, adding biological expertise: “AggloTox – defined particle agglomerates for nanotoxicity studies” is led by the Junior Research Group Structure Formation. The agglomeration sta- tus of nanoparticles might contribute to the degree of toxicity. AggloTox addresses this issue by tho- rough characterization of nanoparticle agglome- ration under experimentally and physiologically relevant conditions. “Envision – Multiscale Textured Biomaterial Mem- branes for Vascular System Implants“ is a joint pro- ject with the Junior Research Group Energy Materi- als. It aims to develop new concepts for the surface of implants based on technologies of INM. Outlook Future studies aim to decipher the relationship between particle properties and local particle dose, as well as location and interaction partners. Also, the impact of low nanoparticle concentrations on specific cell-functions will be examined, focusing on alveolar cells. More generally, the impact of material surfaces on cell-behavior will be analyzed using relevant cell-types. A further focus will be on material effects on DNA and chromosome integrity. 25Jahresbericht 2013 / Annual report 2013 Leica TCS SP5-STED system for investigation of nano cell interactions.