1Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, 2Department of Chemistry, The Johns Hopkins University
We describe experimental details of the synthesis of patterned and reconfigurable particles from two dimensional (2D) precursors. This methodology can be used to create particles in a variety of shapes including polyhedra and grasping devices at length scales ranging from the micro to centimeter scale.
Published February 4, 2013. Keywords: Chemistry, Chemical Engineering, Biomolecular Engineering, Materials Science, Physics, Nanotechnology, Molecular Self-assembly, Electrochemistry, Folding, three dimensional, lithography, colloid, patchy particles, particles, nanoparticles, robotics, drug delivery, microfabrication, nanofabrication, nano, assembly, synthesis, reaction, origami
1Department of Entomology, Louisiana State University Agricultural Center
We present procedures for demonstrating that ligands bind to the surface membrane of the cellulose-digesting protozoa in the gut of Formosan subterranean termites using fluorescent microscopy and that ligands coupled with lytic peptides kill these protozoa in vitro (anaerobic protozoa culture) and in vivo (injection into the termite hindgut).
Published December 29, 2010. Keywords: Microbiology, Isoptera, Coptotermes formosanus, Formosan subterranean termite, termite control, paratransgenesis, symbionts, anaerobic, fluorescence
1Environmental Microfluidics Group, MIT - Massachusetts Institute of Technology
The fabrication of microfluidic channels and their implementation in experiments for studying the chemotactic foraging behaviour of marine microbes within a patchy nutrient seascape and the swimming behaviour of bacteria within shear flow are described.
Published May 28, 2007. Keywords: Microbiology, issue 4, microbial community, chemotaxis, microfluidics
1Department of Biomedical Engineering, University of Wisconsin – Madison
The following protocol outlines the process of isolating, ventilating and instrumenting mouse lungs to measure steady or pulsatile pulmonary vascular pressure-flow relationships in order to quantify the effects of blood flow, airflow, airway changes and vascular changes on right ventricular afterload.
Published April 29, 2011. Keywords: Medicine, ex-vivo, mouse, lung, pulmonary vascular impedance, characteristic impedance
JoVE Applied Physics
1Petroleum & Geosystems Engineering, The University of Texas at Austin
This paper demonstrates the experimental procedure to measure terminal settling velocities of spherical particles in surfactant-based shear thinning viscoelastic fluids. Fluids over a wide range of rheological properties are prepared and settling velocities are measured for a range of particle sizes in unbounded fluids and fluids between parallel walls.
Published January 3, 2014. Keywords: Physics, chemical engineering, settling velocity, Reynolds number, shear thinning, wall retardation
1Department of Mechanical Engineering, Vanderbilt University
Combining monodisperse drop generation with inertial ordering of cells and particles, we describe a method to encapsulate a desired number of cells or particles in a single drop at kHz rates. We demonstrate efficiencies twice exceeding those of unordered encapsulation for single- and double-particle drops.
Published June 15, 2012. Keywords: Bioengineering, Drop-based microfluidics, inertial microfluidics, ordering, focusing, cell encapsulation, single-cell biology, cell signaling
1Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles
When working with media and reagents used to culture microorganisms, aseptic technique must be practiced to ensure contamination is minimized. A variety of plating methods are routinely used to isolate, propagate, or enumerate bacteria and phage, all of which incorporate procedures that maintain the sterility of experimental materials.
Published May 11, 2012. Keywords: Basic Protocols, Streak plates, pour plates, soft agar overlays, spread plates, replica plates, bacteria, colonies, phage, plaques, dilutions
JoVE Clinical and Translational Medicine
1Division of Gastroenterology, Case Western Reserve University School of Medicine, Cleveland, 2Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, 3Digestive Health Research Center, Case Western Reserve University School of Medicine, Cleveland
Over the past few years, new generation endoscopes have emerged as important diagnostic research aids for evaluating murine colitis and colorectal tumors. We present herein a detailed protocol for endoscopic assessment of inflammation and colorectal tumors in mice, as well as a novel scoring system that uses decimal identifiers to document the endoscopic severity of colitis and colorectal tumors.
Published October 16, 2013. Keywords: Medicine, Crohn's disease, ulcerative colitis, colon cancer, Clostridium difficile, SAMP mice, DSS/AOM-colitis, decimal scoring identifier
1Barrow Brain Tumor Research Center, Barrow Neurological Institute
We describe the production and characterization of nanoparticles and microparticles composed of poly(lactic-co-glycolic acid) using vitamin E-TPGS as an emulsifier. By varying formulation parameters such as the concentration of emulsifier, it is possible to produce nanoparticles with mean diameters ranging from 220 nm to 1.98 µm.
Published December 27, 2013. Keywords: Chemistry, Nanoparticles, Microparticles, PLGA, TPGS, drug delivery, scanning electron microscopy, emulsion, polymers
1Fischell Department of Bioengineering, University of Maryland, College Park
Lymph nodes are the immunological tissues that orchestrate immune response and are a critical target for vaccines. Biomaterials have been employed to better target lymph nodes and to control delivery of antigens or adjuvants. This paper describes a technique combining these ideas to inject biocompatible polymer particles into lymph nodes.
Published January 2, 2014. Keywords: Bioengineering, biomaterial, immunology, microparticle, nanoparticle, vaccine, adjuvant, lymph node, targeting, polymer