University of Twente

14 articles published in JoVE

• Engineering

  
  Use of Capillary Aerosol Generator in Continuous Production of Controlled Aerosol for Non-Clinical Studies Didier Goedertier¹, Sandra Schorderet Weber¹, Francesco Lucci¹, Tom Lee², Wei Teck Tan², Falk Radtke¹, Subash Krishnan², Patrick Vanscheeuwijck¹, Arkadiusz K. Kuczaj^1,3, Julia Hoeng^{1 1}PMI R&D, Philip Morris Products S.A., ²PMI R&D, Philip Morris Research Laboratories Pte. Ltd., ³Applied Mathematics, University of Twente The protocol describes the settings and use of a capillary aerosol generator for continuous production of controlled aerosol from a multispecies liquid solution, suitable for steady large-volume aerosol delivery (e.g., in vivo inhalation studies).

• Bioengineering

  
  Multi-timescale Microscopy Methods for the Characterization of Fluorescently-labeled Microbubbles for Ultrasound-Triggered Drug Release Charlotte Nawijn¹, Tim Segers^1,2, Guillaume Lajoinie¹, Ýrr Mørch³, Sigrid Berg^4,5,6, Sofie Snipstad^3,6,7, Catharina de Lange Davies⁷, Michel Versluis^{1 1}Physics of Fluids group, Department of Science and Technology, MESA+ Institute for Nanotechnology and Technical Medical (TechMed) Center, University of Twente, ²BIOS Lab-on-a-Chip group, Max Planck Center Twente for Complex Fluid Dynamics, MESA+ Institute for Nanotechnology and Technical Medical (TechMed) Center, University of Twente, ³Department of Biotechnology and Nanomedicine, SINTEF Industry, ⁴Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, ⁵Department of Health Research, SINTEF Digital, ⁶Cancer Clinic, St. Olav’s Hospital, ⁷Department of Physics, Norwegian University of Science and Technology The presented protocols can be used to characterize the response of fluorescently-labeled microbubbles designed for ultrasound-triggered drug delivery applications, including their activation mechanisms as well as their bioeffects. This paper covers a range of in vitro and in vivo microscopy techniques performed to capture the relevant length and timescales.

• Immunology and Infection

  
  In Vitro Microfluidic Disease Model to Study Whole Blood-Endothelial Interactions and Blood Clot Dynamics in Real-Time Xue D. Manz¹, Hugo J. Albers^2,3, Petr Symersky⁴, Jurjan Aman¹, Andries D. van der Meer³, Harm Jan Bogaard¹, Robert Szulcek^{1,5,6 1}Department of Pulmonary Diseases, Amsterdam UMC, VU University Medical Center, Amsterdam Cardiovascular Sciences (ACS), ²BIOS Lab-on-a-Chip group, University of Twente, ³Applied Stem Cell Technologies Group, University of Twente, ⁴Department of Cardio-thoracic Surgery, Amsterdam UMC, VU University Medical Center, ⁵Institute of Physiology, Charité-Universitätsmedizin, ⁶German Heart Center We present an in vitro vascular disease model to investigate whole blood interactions with patient-derived endothelium. This system allows the study of thrombogenic properties of primary endothelial cells under various circumstances. The method is especially suited to evaluate in situ thrombogenicity and anticoagulation therapy during different phases of coagulation.

• Bioengineering

  
  A Zebrafish Embryo Model for In Vivo Visualization and Intravital Analysis of Biomaterial-associated Staphylococcus aureus Infection Xiaolin Zhang^1,2, Leonie de Boer¹, Oliver W. Stockhammer¹, Dirk W. Grijpma^2,3, Herman P. Spaink⁴, Sebastian A.J. Zaat^{1 1}Department of Medical Microbiology, Amsterdam UMC, ²Technical Medical Center, Department of Biomaterials Science and Technology, University of Twente, ³Department of Biomedical Engineering, W.J. Kolff Institute, University Medical Center Groningen, University of Groningen, ⁴Institute of Biology, Leiden University The present study describes a zebrafish embryo model for in vivo visualization and intravital analysis of biomaterial-associated infection over time based on fluorescence microscopy. This model is a promising system complementing mammalian animal models such as mouse models for studying biomaterial-associated infections in vivo.

• Developmental Biology

  
  Microfluidic Assay for the Assessment of Leukocyte Adhesion to Human Induced Pluripotent Stem Cell-derived Endothelial Cells (hiPSC-ECs) Oleh V. Halaidych¹, Francijna van den Hil¹, Christine L. Mummery^1,2, Valeria V. Orlova^{1 1}Department of Anatomy and Embryology, Leiden University Medical Center, ²Department of Applied Stem Cell Technologies, University of Twente This step-by-step protocol provides a detailed description of the experimental setup and data analysis for the assessment of inflammatory responses in hiPSC-ECs and the analysis of leukocyte adhesion under physiological flow.

• Bioengineering

  
  Fabrication and Validation of an Organ-on-chip System with Integrated Electrodes to Directly Quantify Transendothelial Electrical Resistance Marinke W. van der Helm¹, Mathieu Odijk¹, Jean-Philippe Frimat^1,2, Andries D. van der Meer³, Jan C.T. Eijkel¹, Albert van den Berg¹, Loes I. Segerink^{1 1}BIOS Lab on a Chip group, MIRA Institute for Biomedical Technology and Technical Medicine, MESA+ Institute for Nanotechnology and Max Planck Center for Complex Fluid Dynamics, University of Twente, ²Microsystems, Eindhoven University of Technology, ³Applied Stem Cell Technologies, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente This publication describes the fabrication of an organ-on-chip device with integrated electrodes for direct quantification of transendothelial electrical resistance (TEER). For validation, the blood-brain barrier was mimicked inside this microfluidic device and its barrier function was monitored. The presented methods for electrode integration and direct TEER quantification are generally applicable.

• Developmental Biology

  
  Electrophysiological Analysis of human Pluripotent Stem Cell-derived Cardiomyocytes (hPSC-CMs) Using Multi-electrode Arrays (MEAs) Luca Sala¹, Dorien Ward-van Oostwaard¹, Leon G. J. Tertoolen¹, Christine L Mummery^1,2, Milena Bellin^{1 1}Department of Anatomy and Embryology, Leiden University Medical Center, ²Department of Applied Stem Cell Technologies, University of Twente Electrophysiological characterization of cardiomyocytes derived from human Pluripotent Stem Cells (hPSC-CMs) is crucial for cardiac disease modeling and for determining drug responses. This protocol provides the necessary information to dissociate and plate hPSC-CMs on multi-electrode arrays, measure their field potential, and a method for analyzing QT and RR intervals.

• Medicine

  
  3D Whole-heart Myocardial Tissue Analysis Hans Thijs Van den Broek¹, Leon De Jong^1,2, Pieter A. Doevendans¹, Steven A.J. Chamuleau¹, Frebus J. Van Slochteren*¹, René Van Es*^{1 1}Department of Cardiology, Division Heart and Lungs, University Medical Center Utrecht, ²MIRA Institute, University Twente This protocol describes a novel method for the 3D comparison of whole-heart myocardial tissue with MRI. This is designed for the accurate assessment of intramyocardial injections in the infarct border zone of a chronic porcine model of myocardial infarction.

• Chemistry

  
  Dynamic Electrochemical Measurement of Chloride Ions Yawar Abbas¹, Derk B. de Graaf¹, Wouter Olthuis¹, Albert van den Berg^{1 1}BIOS-Lab on a chip group, MESA+ Institute of Nanotechnology, MIRA Biomedical Technology and Technical Medicine, University of Twente Dynamic measurement of chloride ions is presented. Transition time of an Ag/AgCl electrode, during a chronopotentiometric technique, can give the concentration of chloride ions in electrolyte. This method does not require a stable conventional reference electrode.

• Engineering

  
  Preparation and Friction Force Microscopy Measurements of Immiscible, Opposing Polymer Brushes Sissi de Beer^1,2, Edit Kutnyanszky², Martin H. Müser^1,3, G. Julius Vancso^{2 1}Jülich Supercomputing Centre, Forschungszentrum Jülich, ²Materials Science and Technology of Polymer, MESA+ Institute for Nanotechnology, University of Twente, ³Department of Materials Science and Engineering, Universität des Saarlandes The methodology to perform friction force microscopy experiments for contacting brushes is presented: Two polymer brushes that are grafted from (a) substrates and (b) colloidal probes are slid to show that, by using two contacting immiscible brush systems, friction in sliding contacts is reduced compared to miscible brush systems.

• Chemistry

  
  Atomically Defined Templates for Epitaxial Growth of Complex Oxide Thin Films A. Petra Dral¹, David Dubbink¹, Maarten Nijland¹, Johan E. ten Elshof¹, Guus Rijnders¹, Gertjan Koster^{1 1}MESA+ Institute for Nanotechnology, University of Twente Various procedures are outlined to prepare atomically defined templates for epitaxial growth of complex oxide thin films. Chemical treatments of single crystalline SrTiO3 (001) and DyScO3 (110) substrates were performed to obtain atomically smooth, single terminated surfaces. Ca2 Nb3 O10^- nanosheets were used to create atomically defined templates on arbitrary substrates.

• Engineering

  
  Coherent anti-Stokes Raman Scattering (CARS) Microscopy Visualizes Pharmaceutical Tablets During Dissolution Andrew L. Fussell¹, Peter Kleinebudde², Jennifer Herek¹, Clare J. Strachan³, Herman L. Offerhaus^{1 1}Optical Sciences Group, MESA+ Institute, University of Twente, ²Institute of Pharmaceutics and Biopharmaceutics, Heinrich-Heine University, ³Division of Pharmaceutical Technology, Faculty of Pharmacy, University of Helsinki Coherent anti-Stokes Raman scattering (CARS) microscopy is combined with an intrinsic flow-through dissolution setup to allow in situ and real-time visualization of the surface of pharmaceutical tablets undergoing dissolution. Using this custom-built setup, it is possible to correlate CARS videos with drug dissolution profiles recorded using inline UV absorption spectroscopy.

• Engineering

  
  Preparation and Use of Photocatalytically Active Segmented Ag|ZnO and Coaxial TiO₂-Ag Nanowires Made by Templated Electrodeposition A. Wouter Maijenburg¹, Eddy J.B. Rodijk¹, Michiel G. Maas¹, Johan E. ten Elshof^{1 1}MESA+ Institute for Nanotechnology, University of Twente Procedures are outlined to prepare segmented and coaxial nanowires via templated electrodeposition in nanopores. As examples, segmented nanowires consisting of Ag and ZnO segments, and coaxial nanowires consisting of a TiO2 shell and a Ag core were made. The nanowires were used in photocatalytic hydrogen formation experiments.

• Biology

  
  Microfabrication of Chip-sized Scaffolds for Three-dimensional Cell cultivation Stefan Giselbrecht¹, Eric Gottwald¹, Roman Truckenmueller², Christina Trautmann³, Alexander Welle¹, Andreas Guber⁴, Volker Saile⁴, Thomas Gietzelt⁵, Karl-Friedrich Weibezahn^{1 1}Institute for Biological Interfaces, Karlsruhe Research Centre, ²Institute for BioMedical Technology, University of Twente, ³Department of Materials Research, Institute for Heavy Ion Research, ⁴Institute of Microstructure Technology, Karlsruhe Research Centre, ⁵Institute for Micro Process Engineering, Karlsruhe Research Centre We present two processes for the microfabrication of porous polymer chips for three-dimensional cell cultivation. The first one is hot embossing combined with a solvent vapour welding process. The second one uses a recently developed microthermoforming process combined with ion track technology leading to a significant simplification of manufacture.