Lichtoptische Nanoskopie von Biostrukturen mit fokussierter, strukturierter und homogener Beleuchtung

Es wurden in jüngster Vergangenheit verschiedene Methoden der laseroptischen Fernfeldmikroskopie entwickelt, mit denen es möglich ist, biologische Strukturen zu analysieren, die deutlich unterhalb der klassischen optischen Auflösungsgrenze liegen. In dieser Arbeit wurden die drei physikalisch unterschiedlichen Verfahren 4Pi-Mikroskopie, ”Spatially Modulated Illumination“(SMI)-Mikroskopie und Lokalisationsmikroskopie angewandt. Es wurden die Abbildungseigenschaften des 4Pi-Mikroskops an fluoreszenten Nanokugeln und biologischen Präparaten charakterisiert. Mithilfe von SMI-Mikroskopie konnte die Ausdehnung von Rezeptoranhäufungen in Escherichia coli-Bakterien in Richtung der optischen Achse untersucht werden. Intrinsische Eigenschaften der Fluorophore konnten in der Lokalisationsmikroskopie mit einer Anregungswellenlänge von 488 bzw. 647nm dazu genutzt werden, deren Signale zeitlich voneinander zu trennen und ihre laterale Position zu bestimmen. Mit dieser Methode wurden statistische Distanzanalysen an unterschiedlichen Rezeptorproteinen in Escherichia coli-Bakterien im Vergleich mit simulierten Zufallsverteilungen durchgeführt. Die kleinsten gemessenen intermolekularen Distanzen lagen im Bereich von einigen zehn Nanometern. Die Standardabweichungen der Mittelwerte der Distanzverteilungen lagen dabei im einstelligen Nanometerbereich. Am Motorproteinkomplex der Flagellen von Escherichia coli-Bakterien wurden die Größen zweier Ringstrukturen (ca. 25 und 40nm im Durchmesser) statistisch untersucht. Durch Simulationen der Motorproteinverteilungen wurde der Einfluss der Lokalisationsgenauigkeit und der Detektionseffizienz analysiert. Bei Membrananalysen an Toxoplasma gondii Tachyzoiten erhielt man mithilfe von Bildverarbeitung von Daten der Lokalisationsmikroskopie eine Abschätzung der Distanz zwischen innerem Membrankomplex und äußerer Membran in diesen Parasiten in guter Übereinstimmung mit Ergebnissen aus der Elektronenmikroskopie. Bei der Analyse der Verteilung der Histon H3 Tri-methylierung an Lysin 9 in embryonalen Stammzellen der Maus wurden Vergleiche zwischen einer Wildtyp-Zelllinie und einer knockout-Zelllinie des Polycomb- Gens EED realisiert

Evidenzkarten-basierte Sensorfusion zur Umfelderkennung und Interpretation in der Ernte

Korthals T, Skiba A, Krause T, Jungeblut T. Evidenzkarten-basierte Sensorfusion zur Umfelderkennung und Interpretation in der Ernte. In: Ruckelshausen A, Meyer-Aurich A, Rath T, Recke G, Theuvsen B, eds. Informatik in der Land-, Forst- und Ernährungswirtschaft - Intelligente Systeme - Stand der Technik und neue Möglichkeiten. 2016: 97-100

Service robotics: do you know your new companion? Framing an interdisciplinary technology assessment

Service-Robotic—mainly defined as “non-industrial robotics”—is identified as the next economical success story to be expected after robots have been ubiquitously implemented into industrial production lines. Under the heading of service-robotic, we found a widespread area of applications reaching from robotics in agriculture and in the public transportation system to service robots applied in private homes. We propose for our interdisciplinary perspective of technology assessment to take the human user/worker as common focus. In some cases, the user/worker is the effective subject acting by means of and in cooperation with a service robot; in other cases, the user/worker might become a pure object of the respective robotic system, for example, as a patient in a hospital. In this paper, we present a comprehensive interdisciplinary framework, which allows us to scrutinize some of the most relevant applications of service robotics; we propose to combine technical, economical, legal, philosophical/ethical, and psychological perspectives in order to design a thorough and comprehensive expert-based technology assessment. This allows us to understand the potentials as well as the limits and even the threats connected with the ongoing and the planned implementation of service robots into human lifeworld—particularly of those technical systems displaying increasing grades of autonomy

Quantification of internalized silica nanoparticles via STED microscopy

The development of safe engineered nanoparticles (NPs) requires a detailed understanding of their interaction mechanisms on a cellular level. Therefore, quantification of NP internalization is crucial to predict the potential impact of intracellular NP doses, providing essential information for risk assessment as well as for drug delivery applications. In this study, the internalization of 25 nm and 85 nm silica nanoparticles (SNPs) in alveolar type II cells (A549) was quantified by application of super-resolution STED (stimulated emission depletion) microscopy. Cells were exposed to equal particle number concentrations (9.2 x 10^10 particles mL^-1) of each particle size and the sedimentation of particles during exposure was taken into account. Microscopy images revealed that particles of both sizes entered the cells after 5 h incubation in serum supplemented and serum-free medium. According to the in vitro sedimentation, diffusion, and dosimetry (ISDD) model 20–27 of the particles sedimented. In comparison, 102-103 NPs per cell were detected intracellularly serum-containing medium. Furthermore, in the presence of serum, no cytotoxicity was induced by the SNPs. In serum-free medium, large agglomerates of both particle sizes covered the cells whereas only high concentrations (≥ 3.8 × 10^12 particles mL^-1) of the smaller particles induced cytotoxicity

Quantification of Internalized Silica Nanoparticles via STED Microscopy

The development of safe engineered nanoparticles (NPs) requires a detailed understanding of their interaction mechanisms on a cellular level. Therefore, quantification of NP internalization is crucial to predict the potential impact of intracellular NP doses, providing essential information for risk assessment as well as for drug delivery applications. In this study, the internalization of 25 nm and 85 nm silica nanoparticles (SNPs) in alveolar type II cells (A549) was quantified by application of super-resolution STED (stimulated emission depletion) microscopy. Cells were exposed to equal particle number concentrations (9.2×1010 particles mL−1) of each particle size and the sedimentation of particles during exposure was taken into account. Microscopy images revealed that particles of both sizes entered the cells after 5 h incubation in serum supplemented and serum-free medium. According to the in vitro sedimentation, diffusion, and dosimetry (ISDD) model 20–27% of the particles sedimented. In comparison, 102-103 NPs per cell were detected intracellularly serum-containing medium. Furthermore, in the presence of serum, no cytotoxicity was induced by the SNPs. In serum-free medium, large agglomerates of both particle sizes covered the cells whereas only high concentrations (≥ 3.8 × 1012 particles mL−1) of the smaller particles induced cytotoxicity

MOESM4 of Penetration of CdSe/ZnS quantum dots into differentiated vs undifferentiated Caco-2 cells

Additional file 6. Membrane integrity measurements using CytoTox-ONE™ Assay. Membrane integrity of undifferentiated Caco-2 cells was measured after exposure to QD-COOH and QD-NH2 (16nM) for 24 h. Error bars represent SD of 3 independent experiments. In the presence of QDs, the fluorescence intensity of the positive control decreased. ** significantly different from positive control, p ≤ 0.01

MOESM9 of Penetration of CdSe/ZnS quantum dots into differentiated vs undifferentiated Caco-2 cells

Additional file 5. Differentiated Caco-2 cells exposed to cell culture medium without QDs (ctr). Confocal images of differentiated Caco-2 cells exposed only to cell culture medium. (A) Orthogonal views (xy, xzand yz) showing the intersection planes at the position of the yellow cross-hair. (B) Maximum intensity projection ofthe same z-stack. Cell membrane (cyan) and nucleus (yellow)