25 results match your criteria: "Institute of Complex Systems 7: Biomechanics Forschungszentrum Jülich GmbH[Affiliation]"
Geroscience
December 2019
Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Oklahoma Center for Geroscience, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
Adjustment of cerebral blood flow (CBF) to the increased oxygen and nutrient demands of active brain regions via neurovascular coupling (NVC) has an essential role in maintenance of healthy cognitive function. In advanced age, cerebromicrovascular oxidative stress and endothelial dysfunction impair neurovascular coupling, contributing to age-related cognitive decline. Recently we developed a resveratrol (3,4',5-trihydroxystilbene)-containing fusogenic liposome (FL-RSV)-based molecular delivery system that can effectively target cultured cerebromicrovascular endothelial cells, attenuating age-related oxidative stress.
View Article and Find Full Text PDFNanomaterials (Basel)
July 2019
Forschungszentrum Jülich GmbH, Institute of Complex Systems: ICS-7 Biomechanics, 52428 Jülich, Germany.
Lipid-based nanoparticles, also called vesicles or liposomes, can be used as carriers for drugs or many types of biological macromolecules, including DNA and proteins. Efficiency and speed of cargo delivery are especially high for carrier vesicles that fuse with the cellular plasma membrane. This occurs for lipid mixture containing equal amounts of the cationic lipid DOTAP and a neutral lipid with an additional few percents of an aromatic substance.
View Article and Find Full Text PDFPLoS One
March 2020
Institute of Complex Systems 7: Biomechanics, Forschungszentrum Jülich GmbH, Jülich, Germany.
Considering the essential role of chemotaxis of adherent, slow-moving cells in processes such as tumor metastasis or wound healing, a detailed understanding of the mechanisms and cues that direct migration of cells through tissues is highly desirable. The state-of-the-art chemotaxis instruments (e.g.
View Article and Find Full Text PDFActa Biomater
April 2019
Institute of Neurophysiology, University of Cologne, Cologne, Germany; Department of Pediatric Cardiology, University Hospital Cologne, Cologne, Germany. Electronic address:
Pathophysiological conditions, such as myocardial infarction and mechanical overload affect the mammalian heart integrity, leading to a stiffened fibrotic tissue. With respect to the pathophysiology of cardiac fibrosis but also in the limelight of upcoming approaches of cardiac cell therapy it is of interest to decipher the interaction of cardiomyocytes with fibrotic matrix. Therefore, we designed a hydrogel-based model to engineer fibrotic tissue in vitro as an approach to predict the behavior of cardiomyocytes facing increased matrix rigidity.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2019
Institute for Biophysical Chemistry, Hannover Medical School, 30625 Hannover, Germany;
Int J Mol Sci
January 2018
Forschungszentrum Jülich GmbH, Institute of Complex Systems (ICS-7), Biomechanics, 52425 Jülich, Germany.
Cationic liposomes are frequently used as carrier particles for nucleic acid delivery. The most popular formulation is the equimolar mixture of two components, a cationic lipid and a neutral phosphoethanolamine. Its uptake pathway has been described as endocytosis.
View Article and Find Full Text PDFRev Sci Instrum
August 2017
Institut für Physikalische und Theoretische Chemie der Universität Bonn, Wegelerstrasse 12, 53115 Bonn, Germany.
We modified an epi-illumination light microscope and mounted it on an ultra high vacuum chamber for investigating samples used in a surface science experiment. For easy access and bake out, all optical components are placed outside the vacuum and the sample is imaged through a glass window. The microscope can be operated in reflection brightfield or epifluorescence mode to image the sample surface or fluorescent dye molecules adsorbed on it.
View Article and Find Full Text PDFGlia
July 2017
Department of Neurology, University of Bonn, Bonn, 53127, Germany.
The Eph-ephrin system plays pivotal roles in cell adhesion and migration. The receptor-like functions of the ephrin ligands allow the regulation of intracellular processes via reverse signaling. γ-Secretase mediated processing of ephrin-B has previously been linked to activation of Src, a kinase crucial for focal adhesion and podosome phosphorylation.
View Article and Find Full Text PDFMol Cancer
February 2017
Institute of Pathology, Medical Faculty of the RWTH Aachen University, Aachen, Germany.
Background: Extracellular matrix (ECM) is known to maintain epithelial integrity. In carcinogenesis ECM degradation triggers metastasis by controlling migration and differentiation including cancer stem cell (CSC) characteristics. The ECM-modulator inter- α-trypsin inhibitor heavy chain family member five (ITIH5) was recently identified as tumor suppressor potentially involved in impairing breast cancer progression but molecular mechanisms underlying its function are still elusive.
View Article and Find Full Text PDFInterface Focus
October 2016
Institute for Theoretical Physics, Heidelberg University, Heidelberg, Germany; BioQuant, Heidelberg University, Heidelberg, Germany.
Animal cells use traction forces to sense the mechanics and geometry of their environment. Measuring these traction forces requires a workflow combining cell experiments, image processing and force reconstruction based on elasticity theory. Such procedures have already been established mainly for planar substrates, in which case one can use the Green's function formalism.
View Article and Find Full Text PDFCytometry A
March 2016
ICS-7: Biomechanics, Forschungszentrum Jülich GmbH, Institute of Complex Systems, Jülich, 52425, Germany.
Lipid-based nanoparticles are frequently used for drug or DNA delivery into mammalian cells. However it is difficult to determine whether such particles are taken up via endocytosis or fusion to the plasma membrane. Here, we propose a simple and reliable analytical method to do so based on the unique spectral properties of the fluorescent tracer BODIPY FL.
View Article and Find Full Text PDFJ Biomater Appl
January 2016
Institute of Complex Systems, ICS-7: Biomechanics, Forschungszentrum Jülich GmbH, Jülich, Germany
Purification of defined cell populations from mixed primary cell sources is essential for many biomedical and biotechnological applications but often very difficult to accomplish due to missing specific surface markers. In this study, we developed a new approach for efficient cell population separation based on the specific membrane fusion characteristics of distinct cell types upon treatment with fusogenic liposomes. When such liposomes are conjugated with biotin, specific cell populations can be efficiently surface functionalized by biotin after liposomal treatment while other populations remain unlabeled.
View Article and Find Full Text PDFNat Commun
October 2015
Institute of Complex Systems 7 (ICS-7): Biomechanics, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
Stochastic displacements or fluctuations of biological membranes are increasingly recognized as an important aspect of many physiological processes, but hitherto their precise quantification in living cells was limited due to a lack of tools to accurately record them. Here we introduce a novel technique--dynamic optical displacement spectroscopy (DODS), to measure stochastic displacements of membranes with unprecedented combined spatiotemporal resolution of 20 nm and 10 μs. The technique was validated by measuring bending fluctuations of model membranes.
View Article and Find Full Text PDFNat Commun
September 2015
Institute for Biophysical Chemistry, Hannover Medical School, Carl-Neuberg-Strasse 1, Hannover 30625, Germany.
Cell migration is driven by the establishment of disparity between the cortical properties of the softer front and the more rigid rear allowing front extension and actomyosin-based rear contraction. However, how the cortical actin meshwork in the rear is generated remains elusive. Here we identify the mDia1-like formin A (ForA) from Dictyostelium discoideum that generates a subset of filaments as the basis of a resilient cortical actin sheath in the rear.
View Article and Find Full Text PDFBiochim Biophys Acta
November 2015
Institut für Theoretische Physik and Cluster of Excellence: Engineering of Advanced Materials, Friedrich Alexander Universität Erlangen-Nürnberg, 91052 Erlangen, Germany; Insitut Ruđer Bošković, 10000 Zagreb, Croatia. Electronic address:
The dynamics of formation of macromolecular structures in adherent membranes is a key to a number of cellular processes. However, the interplay between protein reaction kinetics, diffusion and the morphology of the growing domains, governed by membrane mediated interactions, is still poorly understood. Here we show, experimentally and in simulations, that a rich phase diagram emerges from the competition between binding, cooperativity, molecular crowding and membrane spreading.
View Article and Find Full Text PDFBiomaterials
August 2015
Helmholtz Institute for Biomedical Engineering, Stem Cell Biology and Cellular Engineering, RWTH Aachen University Medical School, Aachen, Germany. Electronic address:
Surface topography impacts on cell growth and differentiation, but it is not trivial to generate defined surface structures and to assess the relevance of specific topographic parameters. In this study, we have systematically compared in vitro differentiation of mesenchymal stem cells (MSCs) on a variety of groove/ridge structures. Micro- and nano-patterns were generated in polyimide using reactive ion etching or multi beam laser interference, respectively.
View Article and Find Full Text PDFBiomaterials
August 2014
Center for Physiology and Pathophysiology, Institute for Neurophysiology, University of Cologne, Cologne, Germany; Department of Paediatric Cardiology, University Clinics of Cologne, Cologne, Germany. Electronic address:
Cardiomyocytes (CMs) from induced pluripotent stem (iPS) cells mark an important achievement in the development of in vitro pharmacological, toxicological and developmental assays and in the establishment of protocols for cardiac cell replacement therapy. Using CMs generated from murine embryonic stem cells and iPS cells we found increased cell-matrix interaction and more matured embryoid body (EB) structures in iPS cell-derived EBs. However, neither suspension-culture in form of purified cardiac clusters nor adherence-culture on traditional cell culture plastic allowed for extended culture of CMs.
View Article and Find Full Text PDFBiomaterials
August 2014
Helmholtz-Institute for Biomedical Engineering, Stem Cell Biology and Cellular Engineering, RWTH Aachen University Medical School, Pauwelsstrasse 20, Aachen 52074, Germany. Electronic address:
Matrix elasticity guides differentiation of mesenchymal stem cells (MSCs) but it is unclear if these effects are only transient - while the cells reside on the substrate - or if they reflect persistent lineage commitment. In this study, MSCs were continuously culture-expanded in parallel either on tissue culture plastic (TCP) or on polydimethylsiloxane (PDMS) gels of different elasticity to compare impact on replicative senescence, in vitro differentiation, gene expression, and DNA methylation (DNAm) profiles. The maximal number of cumulative population doublings was not affected by matrix elasticity.
View Article and Find Full Text PDFResveratrol (3,4',5-trihydroxystilbene) is a plant-derived polyphenolic trans-stilbenoid, which exerts multifaceted antiaging effects. Here, we propose a novel delivery system for resveratrol, which significantly increases its cellular uptake into aged cells. Combination of resveratrol with a positively charged lipid component to "conventional" liposomes converts these lipid vesicles to a robust fusogenic system.
View Article and Find Full Text PDFSoft Matter
April 2014
Institute of Complex Systems, ICS-7: Biomechanics, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
Surface patterning with complex molecules has become a valuable tool in cell biology and biotechnology, as it enables one to control cell shape and function in culture. However, this technique for micro-contact printing is normally performed on rigid substrates, e.g.
View Article and Find Full Text PDFActa Biomater
March 2014
Institute of Complex Systems, ICS-7: Biomechanics, Forschungszentrum Jülich GmbH, 52425, Germany. Electronic address:
Cell surface functionalization and target molecule incorporation into living cell membranes without functional damage represent major biotechnological challenges. One possible way to achieve these goals is to induce cell membrane fusion with an artificial membrane containing molecules equipped with reactive groups or ligands. In this work we developed a carrier system to incorporate lipopolysaccharide (LPS), an immune cell activating molecule from Gram-negative bacteria, into mammalian membranes.
View Article and Find Full Text PDFBiol Open
March 2013
Institute of Complex Systems, ICS-7: Biomechanics, Forschungszentrum Jülich GmbH , 52425 Jülich , Germany.
Cardiomyocytes are responsible for the permanent blood flow by coordinated heart contractions. This vital function is accomplished over a long period of time with almost the same performance, although heart properties, as its elasticity, change drastically upon aging or as a result of diseases like myocardial infarction. In this paper we have analyzed late rat embryonic heart muscle cells' morphology, sarcomere/costamere formation and force generation patterns on substrates of various elasticities ranging from ∼1 to 500 kPa, which covers physiological and pathological heart stiffnesses.
View Article and Find Full Text PDFMolecules
January 2012
Institute of Complex Systems, ICS-7: Biomechanics, Forschungszentrum Jülich GmbH, Jülich 52425, Germany.
In this paper a rapid and highly efficient method for controlled incorporation of fluorescent lipids into living mammalian cells is introduced. Here, the fluorescent molecules have two consecutive functions: First, they trigger rapid membrane fusion between cellular plasma membranes and the lipid bilayers of their carrier particles, so called fusogenic liposomes, and second, after insertion into cellular membranes these molecules enable fluorescence imaging of cell membranes and membrane traffic processes. We tested the fluorescent derivatives of the following essential membrane lipids for membrane fusion: Ceramide, sphingomyelin, phosphocholine, phosphatidylinositol-bisphosphate, ganglioside, cholesterol, and cholesteryl ester.
View Article and Find Full Text PDFPLoS One
August 2012
Institute of Complex Systems, ICS-7, Biomechanics, Forschungszentrum Jülich GmbH, Jülich, Germany.
Recognition of external mechanical signals is vital for mammalian cells. Cyclic stretch, e.g.
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