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Author: Meyer, Anne K. × Author: Schmidt, Oliver G. × End date: 2019 × Start date: 2019 ×

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Now showing 1 - 5 of 5
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    Biofunctionalized self-propelled micromotors as an alternative on-chip concentrating system
    (Cambridge : Royal Society of Chemistry, 2014) Restrepo-Pérez, Laura; Meyer, Anne K.; Helbig, Linda; Sanchez, Samuel; Schmidt, Oliver G.
    Sample pre-concentration is crucial to achieve high sensitivity and low detection limits in lab-on-a-chip devices. Here, we present a system in which self-propelled catalytic micromotors are biofunctionalized and trapped acting as an alternative concentrating mechanism. This system requires no external energy source, which facilitates integration and miniaturization.
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    Dimensionality of rolled-up nanomembranes controls neural stem cell migration mechanism
    (Washington D.C. : American Chemical Society, 2015) Koch, Britta; Meyer, Anne K.; Helbig, Linda; Harazim, Stefan M.; Storch, Alexander; Sanchez, Samuel; Schmidt, Oliver G.
    We employ glass microtube structures fabricated by rolledup nanotechnology to infer the influence of scaffold dimensionality and cell confinement on neural stem cell (NSC) migration. Thereby, we observe a pronounced morphology change that marks a reversible mesenchymal to amoeboid migration mode transition. Space restrictions preset by the diameter of nanomembrane topography modify the cell shape toward characteristics found in living tissue. We demonstrate the importance of substrate dimensionality for the migration mode of NSCs and thereby define rolled-up nanomembranes as the ultimate tool for single-cell migration studies.
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    Tailoring three-dimensional architectures by rolled-up nanotechnology for mimicking microvasculatures
    (Cambridge : Royal Society of Chemistry, 2015) Arayanarakool, Rerngchai; Meyer, Anne K.; Helbig, Linda; Sanchez, Samuel; Schmidt, Oliver G.
    Artificial microvasculature, particularly as part of the blood–brain barrier, has a high benefit for pharmacological drug discovery and uptake regulation. We demonstrate the fabrication of tubular structures with patterns of holes, which are capable of mimicking microvasculatures. By using photolithography, the dimensions of the cylindrical scaffolds can be precisely tuned as well as the alignment and size of holes. Overlapping holes can be tailored to create diverse three-dimensional configurations, for example, periodic nanoscaled apertures. The porous tubes, which can be made from diverse materials for differential functionalization, are biocompatible and can be modified to be biodegradable in the culture medium. As a proof of concept, endothelial cells (ECs) as well as astrocytes were cultured on these scaffolds. They form monolayers along the scaffolds, are guided by the array of holes and express tight junctions. Nanoscaled filaments of cells on these scaffolds were visualized by scanning electron microscopy (SEM). This work provides the basic concept mainly for an in vitro model of microvasculature which could also be possibly implanted in vivo due to its biodegradability.
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    Carbonate-based Janus micromotors moving in ultra-light acidic environment generated by HeLa cells in situ
    (London : Nature Publishing Group, 2016) Guix, Maria; Meyer, Anne K.; Koch, Britta; Schmidt, Oliver G.
    Novel approaches to develop naturally-induced drug delivery in tumor environments in a deterministic and controlled manner have become of growing interest in recent years. Different polymeric-based microstructures and other biocompatible substances have been studied taking advantage of lactic acidosis phenomena in tumor cells, which decrease the tumor extracellular pH down to 6.8. Micromotors have recently demonstrated a high performance in living systems, revealing autonomous movement in the acidic environment of the stomach or moving inside living cells by using acoustic waves, opening the doors for implementation of such smart microengines into living entities. The need to develop biocompatible motors which are driven by natural fuel sources inherently created in biological systems has thus become of crucial importance. As a proof of principle, we here demonstrate calcium carbonate Janus particles moving in extremely light acidic environments (pH 6.5), whose motion is induced in conditioned acidic medium generated by HeLa cells in situ. Our system not only obviates the need for an external fuel, but also presents a selective activation of the micromotors which promotes their motion and consequent dissolution in presence of a quickly propagating cell source (i.e. tumor cells), therefore inspiring new micromotor configurations for potential drug delivery systems.
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    Biomimetic microelectronics for regenerative neuronal cuff implants
    (Hoboken, NJ : Wiley, 2015) Karnaushenko, Daniil; Münzenrieder, Niko; Karnaushenko, Dmitriy D.; Koch, Britta; Meyer, Anne K.; Baunack, Stefan; Petti, Luisa; Tröster, Gerhard; Makarov, Denys; Schmidt, Oliver G.
    Smart biomimetics, a unique class of devices combining the mechanical adaptivity of soft actuators with the imperceptibility of microelectronics, is introduced. Due to their inherent ability to self‐assemble, biomimetic microelectronics can firmly yet gently attach to an inorganic or biological tissue enabling enclosure of, for example, nervous fibers, or guide the growth of neuronal cells during regeneration.