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End date: 2024 × DDC: 570 × Publisher: Saarbrücken : Leibniz-Institut für Neue Materialien × WGL Institute: INM ×

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Now showing 1 - 6 of 6
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    Stimulated emission depletion microscopy for imaging of engineered and biological nanostructures
    (Saarbrücken : Leibniz-Institut für Neue Materialien, 2010) Schumann, Christian; Cavelius, Christian; Schübbe, Sabrina; Kraegeloh, Annette
    The investigation of interactions between engineered nanostructures and biological systems is a key component in the assessment of potential environmental and health implications due to the increasing application of nanotechnology. Combining the high specificity of bioconjugate fluorescence labeling techniques with the sub-diffraction resolution of Stimulated Emission Depletion (STED) microscopy and state-of-the-art nonlinear image restoration allows the imaging of these interactions on the length scales demanded by the interaction partners. In this article, we give an overview of the experimental approach and discuss its implications on the biological interpretation of the resulting fluorescence micrographs.
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    Bioinspired pressure actuated adhesive system
    (Saarbrücken : Leibniz-Institut für Neue Materialien, 2011) Paretkar, Dadhichi R.; Kamperman, Marleen; Schneider, Andreas S.; Arzt, Eduard
    We developed a dry snythetic adhesive system inspired by gecko feet that can switch reversibly from adhesion to non-adhesion with applied pressure as external stimulus. Micropatterned polydimethylsiloxane (PDMS) surfaces with pillars of 30 µm length and 10 µm diameter were fabricated using photolithography and moulding. Adhesion properties were determined with a flat probe as a function of preload. For low and moderate applied compressive preloads, measured adhesion was 7.5 times higher on the patterned surfaces than on flat controls whereas for high preloads adhesion dropped to very low values. In situ imaging showed that the increased preload caused the pillars to deform by bending and/or buckling and to lose their adhesive contact. The elasticity of PDMS aids the pillar recovery to the upright position upon removal of preload enabling repeatability of the switch. Such systems have promising properties e.g. for industrial pick-and-carry operations.
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    Biological materials - bioinspiration on different length scales
    (Saarbrücken : Leibniz-Institut für Neue Materialien, 2011) Weiss, Ingrid
    This article investigates nacre and peacock feather rachis from a molecular and structural point of view, in addition to unifying principles in nature that may control hierarchical functions. This biological material serves as an example for deciphering basic principles in nature that may subsequently be used to design new artificial materials and structures.
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    The intracellular localization of inorganic engineered versus biogenic materials: a comparison
    (Saarbrücken : Leibniz-Institut für Neue Materialien, 2011) Kucki, Melanie; Kraegeloh, Annette
    The uptake of engineered nanoobjects into cells is assumed to significantly account for their potential toxicity. By internalisation, nanoparticles are at least temporarily trapped in the confined volume of a single cell and come into close contact with cellular components, like organelles, structural proteins, enzymes or signalling molecules. As cells are highly structured entities, exhibiting various types of chemically and biologically distinct compartments, first of all the uptake mechanism determines which types of molecules are encountered. In this review, an introduction into the compartmentalisation of cells as well as some uptake processes is given. The localisation of engineered materials within cells of human and animal origin is exemplified. On the other hand, many living organisms are known for their ability to intracellularly precipitate inorganic structures. Some of these biogenic materials are chemically and structurally similar to artificially generated nanostructures. Therefore, the localisation of some biogenic structures within cells is also illustrated. Finally, the relevance of the specific cellular localisation for toxicity is discussed.
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    "Gecko-Workshop 2010" - INM initiates new worldwide conference series
    (Saarbrücken : Leibniz-Institut für Neue Materialien, 2011) Kamperman, Marleen; Arzt, Eduard
    In July 2010, scientists from all over the world gathered at INM to discuss gecko inspired adhesion at a workshop entitled "Bioinspired adhesion: from geckos to new products". The talks covered a range of current issues, including natural attachment systems, developments in artificial gecko-mimics, advances in mechanical models and possible products. This was the first dedicated workshop on this topic. The attendees unanimously agreed to create an international workshop series based on the INM example.
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    Fast and sensitive screening of transparent composite materials using polarized light image processing
    (Saarbrücken : Leibniz-Institut für Neue Materialien, 2009) Weiss, Ingrid M.; Heiland, Birgit
    Composite materials of natural origin have remarkable material properties. In order to mimic the various functions of such materials for technical applications, it is necessary to understand the structure and the mechanisms of their formation, a scientific field which is called structural biology. A milestone in the era of structural biology was the application of the polarized light microscope for investigating biological specimens by W. J. Schmidt in 1924. A recent development in polarization technology is the LC-PolScope (Abrio IM™ Imaging System) that has been developed by R. Oldenbourg and his colleagues during the past 20 years. Like conventional polarization microscopy, it probes the local anisotropy of the specimen’s optical properties, such as birefringence or dichroism. Since there is a close relationship between such properties and molecular order in bulk materials, polarization microscopy can be regarded as a submicroscopic technique. The LC-PolScope is especially suitable for investigating biological materials without the need for using contrasting agents such as fluorescent markers. We demonstrated the applicability of this technique for the fast and sensitive screening of biological composite materials. Implications for the characterization of biomineralization phenomena in a quantitative manner are discussed.