JoVE Bioengineering merges both physical and life sciences to understand and predict biological processes. Applying physical science tools to life science questions allow for the discovery of better technologies to measure, diagnose, and clinically treat disease.
1Department of Biomedical Engineering, University of Minnesota
We present a method for microfluidic deposition of patterned genipin and fibronectin on PDMS substrates, allowing extended viability of vascular smooth muscle cell-dense tissues. This tissue fabrication method is combined with previous vascular muscular thin film technology to measure vascular contractility over disease-relevant time courses.
Published June 26, 2015. Keywords: Bioengineering, substrate modification, microfluidics, protein deposition, vascular smooth muscle cells, cell viability, polydimethylsiloxane, genipin, arterial tissue engineering, mechanical properties, in vitro disease model
1Laboratory for Biomaterials and Bioengineering, Department Min-Met-Materials Eng & CHU de Québec Research Center, Canada Research Chair I for the Innovation in Surgery, Laval University, 2NSERC CREATE Program for Regenerative Medicine (NCPRM), Laval University, 3Department Electronics, Information and Bioengineering, Politecnico di Milano, 4Department of Chemical and Materials Engineering, University of Alberta, 5National Institute for Nanotechnology, National Research Council (Canada), 6Department of Chemical and Biochemical Engineering, University of Western Ontario
In this work, we present a technique for the rapid fabrication of living vascular tissues by direct culturing of collagen, smooth muscle cells and endothelial cells. In addition, a new protocol for the mechanical characterization of engineered vascular tissues is described.
Published June 16, 2015. Keywords: Bioengineering, Collagen gel, cell culture, 3D constructs, vascular tissue engineering, bioreactor, mechanical characterization
1Department of Orthopaedic Surgery, University of Michigan Medical School, 2Department of Molecular & Integrative Physiology, University of Michigan Medical School, 3Department of Biomedical Engineering, University of Michigan Medical School, 4Department of Surgery, Section of Plastic Surgery, University of Michigan Medical School
Analysis of the contractile properties of chemically skinned, or permeabilized, skeletal muscle fibers offers a powerful means by which to assess muscle function at the level of the single muscle cell. In this article we outline a valid and reliable technique to prepare and test permeabilized skeletal muscle fibers in vitro.
Published June 16, 2015. Keywords: Bioengineering, Muscle physiology, skeletal muscle, single muscle fiber, permeabilized, cross-sectional area, isometric force, specific force
1Department of Mechanical and Aerospace Engineering, California State University, Long Beach, 2Ximedica, 3School of Engineering, Brown University
Cell migration is an important part of human development and life. In order to understand the mechanisms that can alter cell migration, we present a planar gradient diffusion system to investigate chemotaxis in a 3D collagen matrix, which allows one to overcome modern diffusion chamber limitations of existing assays.
Published June 12, 2015. Keywords: Bioengineering, Chemotaxis, 3D cell migration, diffusion, traction force microscopy, gradient, live-cell imaging
1Department of Mechanical Engineering, National Taiwan University, 2Department of Mechanical Engineering, National Taiwan University of Science and Technology
Herein, we describe a procedure that employs microscale schlieren technique to measure mixing inhomogeneity in a microfluidic device. Through calibration, distribution of concentration gradient can be derived from the micro-schlieren image.
Published June 12, 2015. Keywords: Bioengineering, Physics, schlieren optics, microfluidics, image analysis, flow visualization, full-field measurement, mixing
1School of Materials Science and Engineering, Nanyang Technological University
Recombinant technologies have enabled material designers to create novel artificial proteins with customized functionalities for tissue engineering applications. For example, artificial extracellular matrix proteins can be designed to incorporate structural and biological domains derived from native ECMs. Here, we describe the construction and purification of aECM proteins containing elastin-like repeats. …
Published June 11, 2015. Keywords: Bioengineering, Genetic engineering, protein expression, artificial extracellular matrix proteins, cell-binding domain, elastin-like domains, lower critical solution temperature, inverse transition cycling, phase transition behavior, protein purification
1Institute for Complex Molecular Systems, Department of Biomedical Engineering, Laboratory of Chemical Biology, Eindhoven University of Technology, 2Department of Cardiology, Division Heart and Lungs, Interuniversity Cardiology Institute of the Netherlands (ICIN), University Medical Center Utrecht
Supramolecular hydrogelators based on ureido-pyrimidinones allow full control over the macroscopic gel properties and the sol–gel switching behavior using pH. Here, we present a protocol for formulating and injecting such a supramolecular hydrogelator via a catheter delivery system for local delivery directly in relevant areas in the pig heart.
Published June 7, 2015. Keywords: Bioengineering, supramolecular polymers, hydrogels, catheter injection, drug delivery, pH switchability, pig model
1Experimental Molecular Imaging, RWTH Aachen University, 2Institute for Biomedical Engineering - Biointerface Laboratory, RWTH Aachen University, 3Utrecht Institute for Pharmaceutical Sciences, Utrecht University
We describe a protocol for hybrid imaging, combining fluorescence-mediated tomography (FMT) with micro computed tomography (µCT). After fusion and reconstruction, we perform interactive organ segmentation to extract quantitative measurements of the fluorescence distribution.
Published June 4, 2015. Keywords: Bioengineering, Fluorescence-mediated Tomography, Computed Tomography, Image Segmentation, Multimodal Imaging, Image Analysis, Hybrid Imaging, Biodistribution, Diffuse Optical Tomography
1Department of Mechanical Engineering, University of Ottawa
The protocol described details an experimental procedure to quantify Red Blood Cell (RBC) aggregates under a controlled and constant shear rate, based on image processing techniques. The goal of this protocol is to relate RBC aggregate sizes to the corresponding shear rate in a controlled microfluidic environment.
Published June 4, 2015. Keywords: Bioengineering, Red blood cells, aggregation, microcirculation, microfluidics, micro particle image velocimetry, blood rheology
1Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, 2College of Medicine, University of Illinois at Urbana-Champaign, 3Provena Covenant Medical Centre, 4Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign
A protocol is described to extract primary human cells from surgical colon tumor and normal tissues. The isolated cells are then cultured on soft elastic substrates (polyacrylamide hydrogels) functionalized by an extracellular matrix protein, and embedded with fluorescent microbeads. Traction cytometry is performed to assess cellular contractile stresses.
Published June 4, 2015. Keywords: Bioengineering, Primary human colon tumor cells, Soft Elastic Substrates, Traction force Microscopy, Mechanobiology, Immunofluorescence Microscopy, Cell mechanics