S'identifier

Saarland University

20 ARTICLES PUBLISHED IN JoVE

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Biology

Live Cell Calcium Imaging Combined with siRNA Mediated Gene Silencing Identifies Ca2+ Leak Channels in the ER Membrane and their Regulatory Mechanisms
Sven Lang *1, Nico Schäuble *1, Adolfo Cavalié 2, Richard Zimmermann 1
1Medical Biochemistry and Molecular Biology, Saarland University, 2Experimental and Clinical Pharmacology and Toxicology, Saarland University

The endoplasmic reticulum plays a key role in protein biogenesis and in calcium homeostasis. We have established an experimental system that allows us to address the role of Ca2+ leak channels and to characterize their putative regulatory mechanisms. This system involves siRNA mediated gene silencing and live cell Ca2+ imaging.

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Medicine

Ischemic Tissue Injury in the Dorsal Skinfold Chamber of the Mouse: A Skin Flap Model to Investigate Acute Persistent Ischemia
Yves Harder 1, Daniel Schmauss 1, Reto Wettstein 2, José T. Egaña 1, Fabian Weiss 1, Andrea Weinzierl 1, Anna Schuldt 1, Hans-Günther Machens 1, Michael D. Menger 3, Farid Rezaeian 4
1Department of Plastic Surgery and Hand Surgery, Klinikum rechts der Isar, Technische Universität München, 2Department of Plastic, Reconstructive, Aesthetic and Hand Surgery, University Hospital of Basel, 3Institute for Clinical and Experimental Surgery, University of Saarland, 4Division of Plastic and Hand Surgery, University Hospital Zurich

The window of the murine dorsal skinfold chamber presented visualizes a zone of acute persistent ischemia of a musculocutaneous flap. Intravital epi-fluorescence microscopy permits for direct and repetitive assessment of the microvasculature and quantification of hemodynamics. Morphologic and hemodynamic results can further be correlated with histological and molecular analyses.

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Bioengineering

Studying the Stoichiometry of Epidermal Growth Factor Receptor in Intact Cells using Correlative Microscopy
Diana B. Peckys 1, Niels de Jonge 1,2
1INM-Leibniz Institute for New Materials, 2Department of Physics, University of Saarland

This protocol describes the labeling of epidermal growth factor receptor (EGFR) on COS7 fibroblast cells, and subsequent correlative light- and electron microscopy of whole cells in hydrated state. The label contained fluorescent quantum dots. The protocol can be used to study the stoichiometry of EGFR at the single molecule level.

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Engineering

Experimental Methods for Investigation of Shape Memory Based Elastocaloric Cooling Processes and Model Validation
Marvin Schmidt 1,2, Johannes Ullrich 2, André Wieczorek 3, Jan Frenzel 3, Gunther Eggeler 3, Andreas Schütze 1, Stefan Seelecke 2
1Lab for Measurement Technology, Saarland University, 2Intelligent Material Systems Lab, Saarland University, 3Lab for Material Science, Ruhr Universität Bochum

Experimental methods for investigation of solid state cooling processes and characterization of elastocaloric material properties of Shape Memory Alloys (SMA) are presented. A custom-built test rig has been designed for controlling and comprehensive monitoring of elastocaloric cooling processes. Furthermore, it provides a validation platform for thermomechanically coupled modeling approaches.

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Biology

Residue-specific Incorporation of Noncanonical Amino Acids into Model Proteins Using an Escherichia coli Cell-free Transcription-translation System
Emanuel G. Worst 1, Matthias P. Exner 2, Alessandro De Simone 2, Marc Schenkelberger 1, Vincent Noireaux 3, Nediljko Budisa 2, Albrecht Ott 1
1Department of Experimental Physics, Saarland University, 2Institute of Chemistry, Technische Universität Berlin, 3School of Physics and Astronomy, University of Minnesota

An easy-to-use, cell-free expression protocol for the residue-specific incorporation of noncanonical amino acid analogs into proteins, including downstream analysis, is presented for medical, pharmaceutic, structural and functional studies.

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Medicine

An Intramedullary Locking Nail for Standardized Fixation of Femur Osteotomies to Analyze Normal and Defective Bone Healing in Mice
Tina Histing 1, Michael D. Menger 2, Tim Pohlemann 1, Romano Matthys 3, Tobias Fritz 1, Patric Garcia 1, Moritz Klein 1
1Department of Trauma, Hand and Reconstructive Surgery, Saarland University, 2Institute for Clinical & Experimental Surgery, Saarland University, 3RISystem AG

This protocol describes an osteosynthesis technique using an intramedullary locking nail for standardized fixation of femur osteotomies, which can be used to analyze normal and defective bone healing in mice.

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Engineering

Studying Dynamic Processes of Nano-sized Objects in Liquid using Scanning Transmission Electron Microscopy
Justus Hermannsdörfer 1, Niels de Jonge 1,2
1INM-Leibniz Institute for New Materials, 2Department of Physics, University of Saarland

This protocol describes the operation of a liquid flow specimen holder for scanning transmission electron microscopy of AuNPs in water, as used for the observation of nanoscale dynamic processes.

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Bioengineering

Isolation of Murine Adipose Tissue-derived Microvascular Fragments as Vascularization Units for Tissue Engineering
Florian S. Frueh 1,2, Thomas Später 1, Claudia Scheuer 1, Michael D. Menger 1, Matthias W. Laschke 1
1Institute for Clinical and Experimental Surgery, Saarland University, 2Division of Plastic Surgery and Hand Surgery, University Hospital Zurich, University of Zurich

We present a protocol to isolate adipose tissue-derived microvascular fragments that represent promising vascularization units. They can be rapidly isolated, do not require in vitro processing and, thus, may be used for one-step prevascularization in different fields of tissue engineering.

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Biology

A Simple Fluorescence-based Reporter Assay to Identify Cellular Components Required for Ricin Toxin A Chain (RTA) Trafficking in Yeast
Björn Becker 1, Manfred J. Schmitt 1
1Molecular and Cell Biology, Department of Biosciences and Center of Human and Molecular Biology (ZHMB), Saarland University

In the manuscript, we describe the use of a yeast-based fluorescence reporter assay to identify cellular components involved in the trafficking and killing processes of the cytotoxic A subunit of the plant toxin ricin (RTA).

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Medicine

A Minimally Invasive Model to Analyze Endochondral Fracture Healing in Mice Under Standardized Biomechanical Conditions
Tina Histing 1, Philipp Bremer 1, Mika F. Rollmann 1, Steven Herath 1, Moritz Klein 1, Tim Pohlemann 1, Michael D. Menger 2, Tobias Fritz 1
1Department of Trauma, Hand and Reconstructive Surgery, Saarland University, 2Institute for Clinical & Experimental Surgery, Saarland University

This protocol describes a minimally invasive osteosynthesis technique using an intramedullary screw for standardized stabilization of femur fractures, which can be used to analyze endochondral bone healing in mice.

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Developmental Biology

Thin Film Composite Silicon Elastomers for Cell Culture and Skin Applications: Manufacturing and Characterization
Silviya Boyadzhieva *1,2, Sarah C.L. Fischer *1,2, Svenja Lösch 1,3, Angela Rutz 1, Eduard Arzt 1,2, Klaus Kruttwig 1
1INM - Leibniz Institute for New Materials, 2Department of Materials Science and Engineering, Saarland University, 3University of Applied Sciences Kaiserslautern

A protocol for the manufacturing process of polymeric thin film composite structures possessing either different Young's moduli or thicknesses is presented. Films are produced for advanced cell culture studies or as skin adhesives.

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Immunology and Infection

Light-sheet Microscopy for Three-dimensional Visualization of Human Immune Cells
Rouven Schoppmeyer 1, Renping Zhao 1, Markus Hoth 1, Bin Qu 1
1Department of Biophysics, Center for Integrative Physiology and Molecular Medicine (CIPMM), School of Medicine, Saarland University

Here, we present a protocol to visualize immune cells embedded in a three-dimensional (3D) collagen matrix using light-sheet microscopy. This protocol also elaborates how to track cell migration in 3D. This protocol can be employed for other types of suspension cells in the 3D matrix.

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Bioengineering

Evaluation of the Storage Stability of Extracellular Vesicles
Maximilian Richter 1,2, Kathrin Fuhrmann 1, Gregor Fuhrmann 1,2
1Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Helmholtz Centre for Infection Research (HZI), Biogenic Nanotherapeutics group (BION), 2Department of Pharmacy, Saarland University

Here we present a readily applicable protocol to assess the storage stability of extracellular vesicles, a group of naturally occurring nanoparticles produced by cells. The vesicles are loaded with glucuronidase as a model enzyme and stored under different conditions. After storage, their physicochemical parameters and the activity of the encapsulated enzyme are evaluated.

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Medicine

Scratch Migration Assay and Dorsal Skinfold Chamber for In Vitro and In Vivo Analysis of Wound Healing
Anouar Belkacemi 1, Matthias W. Laschke 2, Michael D. Menger 2, Veit Flockerzi 1
1Institute of Experimental and Clinical Pharmacology and Toxicology, Center for Molecular Signaling (PZMS), Saarland University, 2Institute for Clinical and Experimental Surgery, Saarland University

Here, we present a protocol for an in vitro scratch assay using primary fibroblasts and for an in vivo skin wound healing assay in mice. Both assays are straightforward methods to assess in vitro and in vivo wound healing.

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Chemistry

Covalent Attachment of Single Molecules for AFM-based Force Spectroscopy
Adrianna Kolberg 1, Christiane Wenzel 1, Thorsten Hugel 1,3, Markus Gallei 2, Bizan N. Balzer 1,3
1Institute of Physical Chemistry, Albert-Ludwigs-Universität Freiburg, 2Chair in Polymer Chemistry, Saarland University, 3Cluster of Excellence livMatS at FIT - Freiburg Center for Interactive Materials and Bioinspired Technologies, University of Freiburg

Covalent attachment of probe molecules to atomic force microscopy (AFM) cantilever tips is an essential technique for the investigation of their physical properties. This allows us to determine the stretching force, desorption force and length of polymers via AFM-based single molecule force spectroscopy with high reproducibility.

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Immunology and Infection

P. aeruginosa Infected 3D Co-Culture of Bronchial Epithelial Cells and Macrophages at Air-Liquid Interface for Preclinical Evaluation of Anti-Infectives
Carlos Victor Montefusco-Pereira *1,2, Justus C. Horstmann *1,2, Thomas Ebensen 3, Christoph Beisswenger 4, Robert Bals 4, Carlos A. Guzmán 3, Nicole Schneider-Daum 1, Cristiane de Souza Carvalho-Wodarz 1, Claus-Michael Lehr 1,2
1Department of Drug Delivery, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), 2Department of Pharmacy, Saarland University, 3Department of Vaccinology and Applied Microbiology, Helmholtz Centre for Infection Research, 4Department of Internal Medicine V - Pulmonology, Allergology, Respiratory Intensive Care Medicine, Saarland University Hospital

We describe a protocol for a three-dimensional co-culture model of infected airways, using CFBE41o- cells, THP-1 macrophages, and Pseudomonas aeruginosa, established at the air-liquid interface. This model provides a new platform to simultaneously test antibiotic efficacy, epithelial barrier function, and inflammatory markers.

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Biology

Graphene Enclosure of Chemically Fixed Mammalian Cells for Liquid-Phase Electron Microscopy
Patricia Blach 1,2, Sercan Keskin 1, Niels de Jonge 1,2
1INM-Leibniz Institute for New Materials, 2Department of Physics, Saarland University

Presented here is a protocol for labeling membrane proteins in mammalian cells and coating the sample with graphene for liquid-phase scanning transmission electron microscopy. The stability of the samples against the damage caused by radiation can also studied with this protocol.

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Bioengineering

Metabolic Profiling to Determine Bactericidal or Bacteriostatic Effects of New Natural Products using Isothermal Microcalorimetry
Katarina Cirnski *1,2, Janetta Coetzee *1,2, Jennifer Herrmann 1,2, Rolf Müller 1,2
1Helmholtz Institute for Pharmaceutical Research Saarland, Department of Microbial Natural Products, Helmholtz Centre for Infection Research and Department of Pharmacy, Saarland University, 2Partner Site Hannover-Braunschweig, German Centre for Infection Research (DZIF)

The elucidation of the mode-of-action of a novel antibiotic is a challenging task in the drug discovery process. The goal of the method described here is the application of isothermal microcalorimetry using calScreener in antibacterial profiling to provide additional insight into drug-microbe interactions.

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Medicine

Erythrocyte Sedimentation Rate: A Physics-Driven Characterization in a Medical Context
Alexis Darras 1, Thomas John 1, Christian Wagner 1,2, Lars Kaestner 1,3
1Experimental Physics, Saarland University, 2Department of Physics and Materials Science, University of Luxembourg, 3Theoretical Medicine and Biosciences, Saarland University

Erythrocyte sedimentation rate (ESR) is a physical parameter, often used in routine health checks and medical diagnosis. A theoretical model that allows to extract physically-meaningful parameters from the whole sedimentation curve, based on modern colloidal knowledge, has recently been developed. Here, we present a protocol to automatically collect the ESR over time, and extract the parameters of this recent model from this automated data collection. These refined parameters are also likely to improve the medical testimony.

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Neuroscience

Production of Human Neurogenin 2-Inducible Neurons in a Three-Dimensional Suspension Bioreactor
Jeanette Wihan 1, Isabell Karnatz 1, Isabelle Sébastien 1, Ralf Kettenhofen 1, Benjamin Schmid 2, Christian Clausen 2, Benjamin Fischer 1, Rachel Steeg 3, Heiko Zimmermann 1,4,5,6, Julia C. Neubauer 1,4
1Fraunhofer Project Center for Stem Cell Process Engineering, Fraunhofer Institute for Biomedical Engineering IBMT, 2Bioneer A/S, 3Fraunhofer UK Research Ltd, Technology and Innovation Centre, 4Fraunhofer Institute for Biomedical Engineering IBMT, 5Department of Molecular and Cellular Biotechnology, Saarland University, 6Facultad de Ciencias del Mar, Universidad Católica del Norte

This article describes a protocol for the generation of human induced pluripotent stem cell-derived neurons in a benchtop 3D suspension bioreactor.

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