Two-phase systems in which one is uniformly dispersed in another as particles small enough so they cannot be filtered or will not settle out. The dispersing or continuous phase or medium envelops the particles of the discontinuous phase. All three states of matter can form colloids among each other.
1Chemical and Biomolecular Engineering Department, University of Houston
Confocal microscopy is used to image quiescent and flowing colloid-polymer mixtures, which are studied as model systems for attractive suspensions. Image analysis algorithms are used to calculate structural and dynamic metrics for the colloidal particles that measure changes due to geometric confinement.
Published May 20, 2014. Keywords: Chemistry, confocal microscopy, particle tracking, colloids, suspensions, confinement, gelation, microfluidics, image correlation, dynamics, suspension flow
1Department of Chemistry, Wright State University, 2Department of Neuroscience, Cell Biology, and Physiology, Wright State University
Tangential flow ultrafiltration (TFU) is a recirculation method used for the weight-based separation of biosamples. TFU was adapted to size-select (1-20 nm diameter) and highly concentrate a large volume of polydisperse silver nanoparticles (4 L of 15.2 μg ml-1 down to 4 ml of 8,539.9 μg ml-1) with minimal aggregation.
Published October 4, 2012. Keywords: Chemistry, Biomedical Engineering, Chemical Engineering, Nanotechnology, silver nanoparticles, size selection, concentration, tangential flow ultrafiltration
1Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign
Traditional techniques for fabricating polyacrylamide (PA) gels containing fluorescent probes involve sandwiching a gel between an adherent surface and a glass slide. Here, we show that coating this slide with poly-D-lysine (PDL) and fluorescent probes localizes the probes to within 1.6 µm from the gel surface.
Published September 16, 2014. Keywords: Bioengineering, cell mechanics, polyacrylamide (PA) gel, traction force microscopy, fluorescent beads, poly-D-lysine (PDL), cell culture surface
1Marcoule Institute for Separative Chemistry, UMR 5257 CEA-CNRS-UM2-ENSCM
Acoustic cavitation in liquids submitted to power ultrasound creates transient extreme conditions inside the collapsing bubbles, which are the origin of unusual chemical reactivity and light emission, known as sonoluminescence. In the presence of noble gases, nonequilibrium plasma is formed. The "hot" particles and the photons generated by collapsing bubbles are able to excite species in solution.
Published April 11, 2014. Keywords: Chemistry, Sonochemistry, sonoluminescence, ultrasound, cavitation, nanoparticles, actinides, colloids, nanocolloids
1Department of Physics and Astronomy, The University of Texas at San Antonio, 2Centro de Investigaciones en Optica A. C., 3Department of Biology and Neurosciences Institute, The University of Texas at San Antonio
We synthesized star shaped gold nanostars using a silver seed mediated growth method. The diameter of the nanostars ranges from 200 to 300 nm and the number of tips vary from 7 to 10. The nanoparticles have a broad surface plasmon resonance mode centered in the near infrared.
Published January 15, 2012. Keywords: Bioengineering, thermal ablation, surface plasmon resonance, nanoparticle, nanotechnology, silver seeds
1Oak Ridge Institute for Science and Education, 2Air Force Research Laboratory, Airbase Technology Division, 3School of Materials Science and Engineering, Clemson University
Silica nanoparticles were prepared using acid-catalysis of a siloxane precursor and microwave-assisted synthetic techniques resulting in the controlled growth of nanomaterials ranging from 30-250 nm in diameter. The growth dynamics can be controlled by varying the initial silicic acid concentration, time of the reaction, and temperature of reaction.
Published December 16, 2013. Keywords: Chemistry, Chemistry, chemical manufacturing, chemistry (general), materials (general), nanocomposites, catalysts (chemical), chemistry of compounds, Chemistry and Materials (General), Composite Materials, Inorganic, Organic and Physical Chemistry, Engineering (General), Microwave, nanoparticle, silica, silicic acid, NP, SiO2, synthesis
1Faculty of Pharmacy, University of Sydney, 2Department of Nanobiomedical Science & BK21 PLUS NBM Global Research Center for Regenerative Medicine, Dankook University
Colloidal probe nanoscopy can be used within a variety of fields to gain insight into the physical stability and coagulation kinetics of colloidal systems and aid in drug discovery and formulation sciences using biological systems. The method described within provides a quantitative and qualitative means to study such systems.
Published July 18, 2014. Keywords: Chemistry, Colloidal Probe, Nanoscopy, Suspension Stability, Adhesion Mapping, Force, Particle Interaction, Particle Kinetics
JoVE Immunology and Infection
1Department of Microbiology and Immunology, Louisiana State University Health Sciences Center, 2Center for Molecular and Tumor Virology, Louisiana State University Health Sciences Center, 3Department of Microbiology and Immunology, SUNY Upstate Medical University, 4Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center
The phagokinetic motility track assay is a method used to assess the movement of cells. Specifically, the assay measures chemokinesis (random cell motility) over time in a quantitative manner. The assay takes advantage of the ability of cells to create a measurable track of their movement on colloidal gold-coated coverslips.
Published December 4, 2012. Keywords: Immunology, Microbiology, Cellular Biology, Molecular Biology, gold nanoparticles, coverslips, cell migration, quantitative cell movement, microscopy, motility, assay
JoVE Clinical and Translational Medicine
1Division of Pulmonary and Critical Care Medicine, State University of New York, Buffalo, 2Interventional Pulmonology Section, Division of Medicine, Roswell Park Cancer Institute, State University of New York, Buffalo
Substernal thyroid lesions are common, and need to be differentiated from malignancy. Obtaining percutaneous fine needle biopsy is not possible due to its retrosternal location. This article proposes a protocol for biopsy of substernal thyroid lesions using Endobronchial Ultrasound-guided Transbronchial Needle Aspiration (EBUS-TBNA).
Published November 10, 2014. Keywords: Medicine, substernal thyroid, retrosternal thyroid, intra-thoracic thyroid, goiter, endobronchial ultrasound, EBUS, transbronchial needle aspiration, TBNA, biopsy, needle biopsy
JoVE Clinical and Translational Medicine
1Department of Surgical Oncology, University of Texas M.D. Anderson Cancer Center, 2Department of Chemistry, Rice University, 3Mechanical Engineering and Materials Science, Rice University
We describe the protocols used to investigate the interactions of 13.56 MHz radiofrequency (RF) electric-fields with gold nanoparticle colloids in both non-biological and biological systems (in vitro/vivo). These interactions are being investigated for applications in cancer therapy.
Published August 28, 2013. Keywords: Medicine, Electronics and Electrical Engineering, Life Sciences (General), Radiofrequency, Cancer, Nanoparticles, Hyperthermia, Gold