JoVE Bioengineering
Shape Memory Polymers for Active Cell Culture
Department of Biomedical and Chemical Engineering, Syracuse Biomaterials Institute
A method for developing cell culture substrates with the ability to change topography during culture is described. The method makes use of smart materials known as shape memory polymers that have the ability to memorize a permanent shape. This concept is adaptable to a wide range of materials and applications.
JoVE Applied Physics
Micropunching Lithography for Generating Micro- and Submicron-patterns on Polymer Substrates
Mechanical and Aerospace Engineering, University of Texas at Arlington
A micropunching lithography approach is developed to generate micro- and submicron-patterns on top, sidewall and bottom surfaces of polymer substrates. It overcomes the obstacles of patterning conducting polymers and generating sidewall patterns. This method allows rapid fabrication of multiple features and is free of aggressive chemistry.
JoVE Applied Physics
Micro 3D Printing Using a Digital Projector and its Application in the Study of Soft Materials Mechanics
Department of Mechanical Engineering, Massachusetts Institute of Technology
We demonstrate controlled pattern transformation of swelling gel tubes by elastic instability. A simple projection micro stereo-lithography setup is built using an off-the-shelf digital data projector to fabricate three-dimensional polymeric structures in a layer-by-layer fashion. Swelling hydrogel tubes under mechanical constraint display various circumferential buckling modes depending on dimension.
JoVE Clinical and Translational Medicine
A Murine Model of Stent Implantation in the Carotid Artery for the Study of Restenosis
1Institute for Molecular Cardiovascular Research, RWTH Aachen University, 2Institute for Textile Technology and Mechanical Engineering, RWTH Aachen University, 3Institute for Applied Medical Engineering, Helmholtz-Institute of RWTH Aachen University, 4Department of Experimental Molecular Imaging, RWTH Aachen University, 5Department of Oral and Maxillofacila Surgery, RWTH Aachen University
A model of stent implantation in mouse carotid artery is described. Compared to other similar methods, this procedure is very rapid, simple and accessible, offering the possibility to study in a convenient way the vascular wall reaction to different drug-eluting stents and the molecular mechanisms of restenosis.
JoVE Editorial
July 2011: This Month in JoVE
Here are some highlights from the July 2011 Issue of Journal of Visualized Experiments (JoVE).
JoVE Neuroscience
T-maze Forced Alternation and Left-right Discrimination Tasks for Assessing Working and Reference Memory in Mice
1Division of Systems Medical Science, Institute for Comprehensive Medical Science, Fujita Health University, 2Japan Science and Technology Agency, Core Research for Evolutionary Science and Technology (CREST), 3Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences, National Institutes of Natural Sciences
This article presents the protocol of T-maze tests using a modified automated apparatus for assessing the learning and memory functions in mice.
JoVE Applied Physics
Fabrication, Densification, and Replica Molding of 3D Carbon Nanotube Microstructures
1Mechanosynthesis Group, Department of Mechanical Engineering, University of Michigan, 2IMEC, Belgium
We present methods for fabrication of patterned microstructures of vertically aligned carbon nanotubes (CNTs), and their use as master molds for production of polymer microstructures with organized nanoscale surface texture. The CNT forests are densified by condensation of solvent onto the substrate, which significantly increases their packing density and enables self-directed formation of 3D shapes.
JoVE Chemistry
Template Directed Synthesis of Plasmonic Gold Nanotubes with Tunable IR Absorbance
Department of Chemistry, University of Toronto
Solution-suspendable gold nanotubes with controlled dimensions can be synthesized by electrochemical deposition in porous anodic aluminum oxide (AAO) membranes using a hydrophobic polymer core. Gold nanotubes and nanotube arrays hold promise for applications in plasmonic biosensing, surface-enhanced Raman spectroscopy, photo-thermal heating, ionic and molecular transport, microfluidics, catalysis and electrochemical sensing.
JoVE Applied Physics
Controlling the Size, Shape and Stability of Supramolecular Polymers in Water
1Organic Chemistry Institute and CeNTech, Westfälische Wilhelms-Universität Münster, 2Laboratory of Macromolecular and Organic Chemistry, Institute for Complex Molecular Systems, Eindhoven University of Technology, 3Laboratory of Materials and Interface Chemistry and Soft Matter Research Unit, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology
The goal of this experiment is to determine and control the size, shape and stability of self-assembled discotic amphiphiles in water. For aqueous based supramolecular polymers such level of control is very difficult. We apply a strategy using both repulsive and attractive interactions. The experimental techniques applied to characterize this system are broadly applicable.
JoVE General
Microfabrication of Chip-sized Scaffolds for Three-dimensional Cell cultivation
1Institute 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.
JoVE Bioengineering
Polymer Microarrays for High Throughput Discovery of Biomaterials
1Laboratory of Biophysics and Surface Analysis, University of Nottingham, 2School of Molecular Medical Sciences, University of Nottingham, 3David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology
A description of the formation of a polymer microarray using an on-chip photopolymerization technique. The high throughput surface characterization using atomic force microscopy, water contact angle measurements, X-ray photoelectron spectroscopy and time of flight secondary ion mass spectrometry and a cell attachment assay is also described.
JoVE Neuroscience
Brain Imaging Investigation of the Memory-Enhancing Effect of Emotion
1Centre for Neuroscience, University of Alberta, 2Neuroscience Program, University of Illinois, Urbana-Champaign, 3Center for Cognitive Neuroscience, Duke University, 4Psychology Department, Neuroscience Program, & Beckman Institute, University of Illinois, Urbana-Champaign
We present a protocol that uses functional magnetic resonance imaging to investigate the neural correlates of the memory-enhancing effect of emotion. This protocol allows identification of brain activity specifically linked to memory-related processing, contrary to more general perceptual processing, and can be used with healthy and clinical populations.
JoVE Clinical and Translational Medicine
A Zebrafish Model of Diabetes Mellitus and Metabolic Memory
1Dr. William M. Scholl College of Podiatric Medicine, Rosalind Franklin University of Medicine and Science, 2Chicago Medical School, Rosalind Franklin University of Medicine and Science
Metabolic memory is the phenomenon by which diabetic complications persist and progress unimpeded even after euglycemia is achieved pharmaceutically. Here we describe a diabetes mellitus zebrafish model which is unique in that it allows for the examination of the mitotically transmissible epigenetic components of metabolic memory in vivo.
JoVE Neuroscience
C. elegans Positive Butanone Learning, Short-term, and Long-term Associative Memory Assays
1Department of Molecular Biology, Lewis-Sigler Institute for Integrative Genomics, Princeton University, 2Lewis-Sigler Institute for Integrative Genomics, Princeton University
Here we describe methods to test C. elegans associative learning and short- and long-term associative memory. These population assays employ the worms abilities to chemotax toward volatile odorants, and form positive associations upon pairing food with the chemoattractant butanone. Increasing the number of conditioning periods induces long-term memory.
JoVE Editorial
November 2011: This Month in JoVE
Here are some highlights from the November 2011 Issue of Journal of Visualized Experiments (JoVE).
JoVE Neuroscience
Behavioural Pharmacology in Classical Conditioning of the Proboscis Extension Response in Honeybees (Apis mellifera)
Fachbereich Bio/Chem/Pharm, Institut für Biologie – Neurobiologie, Freie Universität Berlin
We demonstrate how to implement a behavioral pharmacology method in an appetitive olfactory conditioning paradigm in honeybees (Apis mellifera) by systemic application of drugs. This method allows investigation of the mechanisms underlying learning and memory formation in a simple and reliable way.
JoVE Neuroscience
Brain Imaging Investigation of the Neural Correlates of Emotional Autobiographical Recollection
1Department of Psychiatry, University of Alberta, Edmonton, 2Psychology Department, University of Illinois, Urbana-Champaign, 3Neuroscience Program, University of Illinois, Urbana-Champaign, 4Beckman Institute for Advanced Science & Technology, University of Illinois, Urbana-Champaign
We present a protocol that allows investigation of the neural correlates of recollecting emotional autobiographical memories, using functional magnetic resonance imaging. This protocol can be used with both healthy and clinical participants.
JoVE Neuroscience
Eye Movement Monitoring of Memory
1Rotman Research Institute, 2Department of Psychology, University of Toronto, 3Department of Psychiatry, University of Toronto
Eye movement monitoring (or eye tracking) reveals where in space the eyes linger, when and for how long. Here, we demonstrate how eye tracking can be used to investigate the integrity of memory in multiple participant populations, without requiring verbal, or otherwise explicit, reports.
JoVE Clinical and Translational Medicine
Quantifying Cognitive Decrements Caused by Cranial Radiotherapy
Department of Radiation Oncology, University of California Irvine
Cognitive impairment resulting from the radiotherapeutic management of brain tumors represents a clinically intractable condition that adversely impacts quality of life. The capability to critically evaluate potential interventions for ameliorating radiation-induced cognitive decrements ultimately depends on the capability to undertake rigorous quantitative assessments of cognition.
JoVE Neuroscience
Assaying Locomotor, Learning, and Memory Deficits in Drosophila Models of Neurodegeneration
Department of Molecular and Cellular Pharmacology, University of Miami, Miller School of Medicine
Behavior assays for measuring locomotor functions, learning, and memory abilities in Drosophila.
JoVE Chemistry
Fabricating Nanogaps by Nanoskiving
The fabrication of electrically addressable, high-aspect-ratio (> 1000:1) metal nanowires separated by gaps of single nanometers using either sacrificial layers of aluminum and silver or self-assembled monolayers as templates is described. These nanogap structures are fabricated without a clean room or any photo- or electron-beam lithographic processes by a form of edge lithography known as nanoskiving.
JoVE Bioengineering
Cell Co-culture Patterning Using Aqueous Two-phase Systems
1Department of Biomedical Engineering, University of Michigan, 2Department of Macromolecular Science and Engineering, University of Michigan
Aqueous two-phase systems were used to simultaneously pattern multiple populations of cells. This fast and easy method for cell patterning takes advantage of the phase separation of aqueous solutions of dextran and polyethylene glycol and the interfacial tension that exists between the two polymer solutions.
JoVE Bioengineering
Tri-layered Electrospinning to Mimic Native Arterial Architecture using Polycaprolactone, Elastin, and Collagen: A Preliminary Study
1Department of Biomedical Engineering, Virginia Commonwealth University, 2Department of Anatomy and Neurobiology, Virginia Commonwealth University, 3Department of Cardiovascular Surgery, University Hospital of Geneva
The aim of this study was to mimic the native three layered architecture of the arterial wall. To accomplish this, electrospinning was employed with the use of a 3-1 (input-output) nozzle and blends of polycaprolactone, elastin, and collagen.
JoVE Bioengineering
Tissue Engineering of the Intestine in a Murine Model
This article and the accompanying video present our protocol for generating tissue-engineered intestine in the mouse, using an organoid units-on-scaffold approach.
JoVE Clinical and Translational Medicine
An Investigation of the Effects of Sports-related Concussion in Youth Using Functional Magnetic Resonance Imaging and the Head Impact Telemetry System
1Graduate Department of Rehabilitation Science, University of Toronto, 2Occupational Science and Occupational Therapy, University of Toronto, 3Department of Psychology, University of Toronto, 4Bloorview Kids Rehab, 5Toronto Rehab, 6Cognitive Neurology, Sunnybrook Health Sciences Centre, 7Faculty of Medicine, University of Toronto
This article provides an overview of a multi-modal approach to mild traumatic brain injury diagnosis and recovery in youth. This approach combines neuropsychological testing with functional magnetic resonance imaging and the Head Impact Telemetry System to monitor the relationship between head impacts and brain activity during cognitive testing.
JoVE Immunology and Infection
Generation of Induced Regulatory T Cells from Primary Human Naïve and Memory T Cells
Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky
We describe a method for generating regulatory, memory and naïve T cells from a single human blood donor. Polarized Tregs can be then compared to other subsets in a variety of genetic and functional applications with genetic homogeneity, including a suppression assay also detailed here.
JoVE General
Fabrication and Use of MicroEnvironment microArrays (MEArrays)
1Life Science Division, Lawrence Berkeley National Laboratory, 2Department of Comparative Biochemistry, University of California, Berkeley
A combinatorial functional screening method for gaining insights into the impacts of the molecular composition of microenvironments on cellular functions is described. The method takes advantage of existing microarray-based technologies to generate arrays of defined combinatorial microenvironments that support cell adhesion and functional analysis.
JoVE Bioengineering
High-throughput Synthesis of Carbohydrates and Functionalization of Polyanhydride Nanoparticles
1Department of Chemical and Biological Engineering, Iowa State University, 2Department of Chemistry, Iowa State University
In this article, a high throughput method is presented for the synthesis of oligosaccharides and their attachment to the surface of polyanhydride nanoparticles for further use in targeting specific receptors on antigen presenting cells.
JoVE Bioengineering
Combinatorial Synthesis of and High-throughput Protein Release from Polymer Film and Nanoparticle Libraries
Department of Chemical and Biological Engineering, Iowa State University
This method describes the combinatorial synthesis of biodegradable polyanhydride film and nanoparticle libraries and the high-throughput detection of protein release from these libraries.
JoVE Bioengineering
Hydrophobic Salt-modified Nafion for Enzyme Immobilization and Stabilization
Departments of Chemistry and Materials Science and Engineering, University of Utah
This article will describe the procedure for synthesizing a hydrophobically modified Nafion enzyme immobilization membrane and how to immobilize proteins and/or enzymes within the membrane and test their specific activity.
JoVE General
Procedure for Fabricating Biofunctional Nanofibers
1Department of Chemistry, Clark Atlanta University, 2Department of Physics, Clark Atlanta University, 3Department of Chemistry and Chemical Biology, Cornell University
An efficient approach for preparing nanofibers decorated with functional groups capable of specifically interacting with proteins is described. The approach first requires the preparation of a polymer functionalized with the appropriate functional group. The functional polymer is fabricated into nanofibers by electrospinning. The effectiveness of the binding of the nanofibers with a protein is studied by confocal microscopy.
JoVE Bioengineering
Postproduction Processing of Electrospun Fibres for Tissue Engineering
1Materials Science and Engineering, University of Sheffield, 2Department of Biomedical Science, University of Sheffield, 3Department of Chemistry, University of Sheffield
Electrospun scaffolds can be processed post production for tissue engineering applications. Here we describe methods for spinning complex scaffolds (by consecutive spinning), for making thicker scaffolds (by multi-layering using heat or vapour annealing), for achieving sterility (aseptic production or sterilisation post production) and for achieving appropriate biomechanical properties.
JoVE Immunology and Infection
Multicolor Flow Cytometry Analyses of Cellular Immune Response in Rhesus Macaques
1Department of Immunology, MD Anderson Cancer Center - University of Texas, 2Department of Medicine, University of Miami
We demonstrate the utility of multicolor flow cytometry for detailed phenotypic and functional characterization of total as well as memory subsets of CD4+ and CD8+ T cells in rhesus macaques, the ideal model for HIV/AIDS vaccine studies.
JoVE Bioengineering
Electrospinning Fundamentals: Optimizing Solution and Apparatus Parameters
1Department of Biomedical Engineering, University of Michigan, 2State Key Laboratory of Bioelectronics, Southeast University, 3Department of Neurology, University of Michigan, 4Geriatrics Research, Education and Clinical Center, Veterans Affairs Ann Arbor Healthcare Center
Electrospinning techniques can create a variety of nanofibrous scaffolds for tissue engineering or other applications. We describe here a procedure to optimize the parameters of the electrospinning solution and apparatus to obtain fibers with the desired morphology and alignment. Common problems and troubleshooting techniques are also presented.
JoVE Neuroscience
Correlating Behavioral Responses to fMRI Signals from Human Prefrontal Cortex: Examining Cognitive Processes Using Task Analysis
1Department of Psychology, Centre for Vision Research, York University, 2Department of Biology, Centre for Vision Research, York University
The goal of our research is to correlate behavior to brain activity. Accurate behavioral measures and imaging techniques allow us to elucidate brain-behavior relationships.
JoVE General
Electrospinning Fibrous Polymer Scaffolds for Tissue Engineering and Cell Culture
Department of Bioengineering, University of Pennsylvania
The process of electrospinning polymers for tissue engineering and cell culture is addressed in this article. Specifically, the electrospinning of photoreactive macromers with additional processing capabilities of photopatterning and multi-polymer electrospinning is described.
JoVE Neuroscience
The Dig Task: A Simple Scent Discrimination Reveals Deficits Following Frontal Brain Damage
Department of Psychology, Southern Illinois University at Carbondale
In this protocol, a novel application of scent discrimination is described. The Dig task is a reasonably inexpensive task that can be used to assess frontally-mediated cognition following brain damage.
JoVE General
Cellular Encapsulation in 3D Hydrogels for Tissue Engineering
1Department of Bioengineering, University of Pennsylvania, 2Department of Bioengineering, University of Pennsylvania-School of Medicine
We present protocols for the 3-dimensional (3D) encapsulation of cells within synthetic hydrogels. The encapsulation procedure is outlined for two commonly used methods of crosslinking (michael-type addition and light-initiated free radical mechanisms), as well as a number of techniques for assessing encapsulated cell behavior.
JoVE Bioengineering
Methods Development for Blood Borne Macrophage Carriage of Nanoformulated Antiretroviral Drugs
Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center
Nanoparticles of indinavir, ritonavir, efavirenz and atazanavir were manufactured using wet milling, homogenization and ultrasonication. These nanoformulations, collectively termed nanoformulated antiretroviral therapy (nanoART), assessed macrophage-based drug delivery. Monocyte-derived macrophage nanoART uptake, retention and sustained release were determined. These preliminary studies suggest the potential of nanoART for clinical use.
JoVE Bioengineering
Evaluation of Polymeric Gene Delivery Nanoparticles by Nanoparticle Tracking Analysis and High-throughput Flow Cytometry
1Biomedical Engineering Department, Johns Hopkins University School of Medicine, 2Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, 3Wilmer Eye Institute, Johns Hopkins University School of Medicine, 4Institute for Nanobiotechnology, Johns Hopkins University School of Medicine
A protocol for nanoparticle tracking analysis (NTA) and high-throughput flow cytometry to evaluate polymeric gene delivery nanoparticles is described. NTA is utilized to characterize the nanoparticle particle size distribution and the plasmid per particle distribution. High-throughput flow cytometry enables quantitative transfection efficacy evaluation for a library of gene delivery biomaterials.
JoVE General
Morris Water Maze Experiment
Department of Psychology, Michigan State University (MSU)
The Morris water maze is a well-accepted tool used to document the involvement of the hippocampus in a behavioral task.
JoVE Applied Physics
A Method to Fabricate Disconnected Silver Nanostructures in 3D
1School of Engineering and Applied Sciences, Harvard University, 2Department of Physics, Harvard University
Femtosecond-laser direct-writing is frequently used to create three-dimensional (3D) patterns in polymers and glasses. However, patterning metals in 3D remains a challenge. We describe a method for fabricating silver nanostructures embedded inside a polymer matrix using a femtosecond laser centered at 800 nm.
JoVE Neuroscience
Brain Imaging Investigation of the Neural Correlates of Emotion Regulation
1Department of Psychology, University of Illinois, Urbana-Champaign, 2Department of Computing Science, University of Alberta, Edmonton, 3Department of Psychiatry, University of Alberta, Edmonton, 4Department of Psychology, University of Alberta, Edmonton, 5Centre for Neuroscience, University of Alberta, Edmonton, 6Neuroscience Program, University of Illinois, Urbana-Champaign, 7Beckman Institute, University of Illinois, Urbana-Champaign
We present a protocol that allows investigation of the neural correlates of deliberate and automatic emotion regulation, using functional magnetic resonance imaging. This protocol can be used in healthy participants, both young and older, as well as in clinical patients.
JoVE General
C. elegans Chemotaxis Assay
1Life Sciences, Queen's University, 2Department of Chemical Engineering, Queen's University, 3Department of Biology, Queen's University
A method of quantitatively evaluating the chemotactic response of Caenorhabditis elegans is described. A chemotactic index (CI) was employed as a way to precisely evaluate the response of worms to certain targets, and serve as a platform of comparison between strains and compounds of interest.
JoVE Neuroscience
Extinction Training During the Reconsolidation Window Prevents Recovery of Fear
1Departments of Psychiatry and Neuroscience, and Friedman Brain Institute, Mt. Sinai School of Medicine, 2Department of Psychology, New York University, 3Department of Psychology and Center for Neural Science, New York University
Conditioned fear can be diminished through an inhibitory process called extinction, but can resurface under conditions such as the passage of time or exposure to stress. Our protocol presents a novel way of preventing fear recovery by introducing extinction during the reconsolidation window (the re-storage phase of a reactivated memory).
JoVE General
Rapid and Efficient Generation of Neurons from Human Pluripotent Stem Cells in a Multititre Plate Format
1Max Planck Institute for Molecular Biomedicine, 2Medical Faculty, University of Münster
Protocols for neuronal differentiation of pluripotent human stem cells (hPSCs) are often time-consuming and require substantial cell culture skills. Here, we have adapted a small molecule-based differentiation procedure to a multititre plate format, allowing simple, rapid, and efficient generation of human neurons in a controlled manner.
JoVE General
Operant Learning of Drosophila at the Torque Meter
Department of Neurobiology, Free University of Berlin
Measuring the yaw torque of tethered Drosophila with the torque meter allows the neuroscientist exquisite control of the stimulus situation of the experimental animal. Together with the unique genetic tools available in the fruit fly, this paradigm is used for a wide variety of neurobiological research.
JoVE Bioengineering
Fabrication of Micropatterned Hydrogels for Neural Culture Systems using Dynamic Mask Projection Photolithography
Biomedical Engineering, Tulane University
Simple techniques are described for the rapid production of microfabricated neural culture systems using a digital micromirror device for dynamic mask projection lithography on regular cell culture substrates. These culture systems may be more representative of natural biological architecture, and the techniques described could be adapted for numerous applications.
JoVE Bioengineering
Formulation of Diblock Polymeric Nanoparticles through Nanoprecipitation Technique
1Laboratory of Nano- and Translational Medicine, Department of Radiation Oncology, Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, 2Carolina Center for Nanotechnology Excellence, University of North Carolina
This article describes a nanoprecipitation method to synthesize polymer-based nanoparticles using diblock co-polymers. We will discuss the synthesis of diblock co-polymers, the nanoprecipitation technique, and potential applications.
JoVE General
OLIgo Mass Profiling (OLIMP) of Extracellular Polysaccharides
1Energy Biosciences Institute, University of California, Berkeley, 2Department of Plant and Microbial Biology, University of California, Berkeley
A rapid way is described to gain insights into the structure of polysaccharides in an extracellular matrix. The method takes advantage of the specificity of glycosylhydrolases and the sensitivity of mass spectrometry allowing minute amounts of materials to be analyzed. This technique is adaptable to be used directly on tissue itself.
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