A5084767972- Microfluidic and Capillary Electrophoresis Applications
- Microfluidic and Bio-sensing Technologies
- Innovative Microfluidic and Catalytic Techniques Innovation
- Lipid Membrane Structure and Behavior
- Field-Flow Fractionation Techniques
- Nanoparticle-Based Drug Delivery
- Nanopore and Nanochannel Transport Studies
- Electrowetting and Microfluidic Technologies
- Advancements in Transdermal Drug Delivery
- Extracellular vesicles in disease
- Electrostatics and Colloid Interactions
- Advanced biosensing and bioanalysis techniques
- Advanced Drug Delivery Systems
- RNA Interference and Gene Delivery
- 3D Printing in Biomedical Research
- Chemical Synthesis and Analysis
- Gold and Silver Nanoparticles Synthesis and Applications
- Polymer Nanocomposite Synthesis and Irradiation
- Electrohydrodynamics and Fluid Dynamics
- Advanced Polymer Synthesis and Characterization
- MicroRNA in disease regulation
- Hydrogels: synthesis, properties, applications
- Analytical Chemistry and Chromatography
- Polymer Nanocomposites and Properties
- Micro and Nano Robotics
National Institute of Standards and Technology
2014-2025
Material Measurement Laboratory
2013-2025
National Institute of Standards
2014
University of Maryland, College Park
2007-2008
George Mason University
2006
Northwestern University
2001-2003
University of Ottawa
2001-2002
Traditional liposome preparation methods are based on mixing of bulk phases, leading to inhomogeneous chemical and/or mechanical conditions during formation; hence liposomes often polydisperse in size and lamellarity. Here we show the formation that encapsulate reagents a continuous two-phase flow microfluidic network with precision control from 100 300 nm by manipulation liquid rates. We demonstrate creating solvent−aqueous interfacial region format is homogeneous controllable length scale...
We investigate the formation of unilamellar lipid vesicles (liposomes) with diameters tens nanometers by controlled microfluidic mixing and nanoparticle determination (COMMAND). Our study includes liposome synthesis experiments numerical modeling our implementation batch solvent injection method. consider from perspective fluid interfaces convective-diffusive mixing, as we find that bulk flow parameters including hydrodynamically focused alcohol stream width, final concentration, shear...
A new method to tailor liposome size and distribution in a microfluidic format is presented. Liposomes are spherical structures formed from lipid bilayers that tens of nanometers several micrometers diameter. Liposome tailored for particular application inherently important vivo applications such as drug delivery transfection across nuclear membranes gene therapy. Traditional laboratory methods preparation require postprocessing steps, sonication or membrane extrusion, yield formulations...
We compared four orthogonal technologies for sizing, counting, and phenotyping of extracellular vesicles (EVs) synthetic particles. The platforms were: single-particle interferometric reflectance imaging sensing (SP-IRIS) with fluorescence, nanoparticle tracking analysis (NTA) microfluidic resistive pulse (MRPS), nanoflow cytometry measurement (NFCM). EVs from the human T lymphocyte line H9 (high CD81, low CD63) promonocytic U937 (low high were separated culture conditioned medium (CCM) by...
Microfluidic hydrodynamic focusing of an alcohol–lipid mixture into a narrow fluid stream by two oblique buffer streams provides controlled and reproducible method forming phospholipid bilayer vesicles (i.e., liposomes) with relatively monodisperse specific size ranges. Previous work has established that liposome can be changing the relative absolute flow rates fluids. In other previous work, kinetic (non-equilibrium) theoretical description detergent dilution formation was developed, in...
Niosomes are synthetic membrane vesicles formed by self-assembly of nonionic surfactant, often in a mixture with cholesterol and dicetyl phosphate. Because their inner aqueous core bilayer shell, niosomes commonly used as carriers treatment agents for pharmaceutical cosmetic applications or contrast clinical imaging applications. In those applications, considered more economical stable alternative to biological counterpart (i.e., liposomes). However, conventional bulk method niosome...
3D microfluidic hydrodynamic focusing for the synthesis of monodisperse nanoscale liposomes.
Microfluidic-directed formation of liposomes is combined with in-line sample purification and remote drug loading for single step, continuous-flow synthesis nanoscale vesicles containing high concentrations stably loaded compounds. Using an on-chip microdialysis element, the system enables rapid large transmembrane pH ion gradients, followed by immediate introduction amphipathic real-time into liposomes. The microfluidic process drug-laden : lipid molar ratios up to 1.3, a total residence...
Abstract An emulsion of silicone oil droplets in aqueous buffer produces a distinctive series peaks or resonances the side scatter histogram flow cytometer. As many as 12 are observed violet‐side channel at 405 nm, with half that number blue 488 nm. Using index refraction and buffer, wavelength light, collection angle gain instrument, we assign to specific diameters which Mie occur. With close match for ( n = 1.417 nm) biological materials, these could form basis finely spaced size...
Technologies that allow for high-throughput, economical, and accurate single nucleotide polymorphism (SNP) genotyping are becoming crucial modern genomic efforts. Here, we present a method multiplexed single-base extension (SBE) takes advantage of the unique separation modalities made possible via end-labeled free-solution electrophoresis (ELFSE). Three SBE oligonucleotide primers, which probe mutations clinical importance in human p53 gene, were covalently conjugated to three polypeptoid...
Rapid, robust, and economical fabrication of fluidic microchannels is fundamental importance for the successful development disposable lab-on-a-chip devices. In this work, we present a solvent-actuated bonding method fabricating polymeric microfluidic devices at room temperature. A PMMA sheet with an imprinted microchannel was clamped to blank sheet, then 80 +/- 5 muL acetone (bonding solvent) introduced one end channel aspirated out other end. As solvent moved down channel, capillary forces...
Nanosized gel particles (nanogels) are of interest for a variety applications, including drug delivery and single-molecule encapsulation. Here, we employ the cores nanoscale liposomes as reaction vessels to template assembly calcium alginate nanogels. For our experiments, liposome formulation with high bilayer melting temperature (Tm) is selected, sodium encapsulated in liposomal core. The then placed an aqueous buffer containing chloride, raised up Tm. This allows permeation Ca2+ ions...
A new technique is demonstrated for the simultaneous concentration and high-resolution separation of chiral compounds. With temperature gradient focusing, a combination gradient, an applied electric field, buffer with temperature-dependent ionic strength used to cause analytes move equilibrium, zero-velocity points along microchannel or capillary. Different are thus separated spatially concentrated in manner that resembles isoelectric focusing but applicable greater variety including small...
Abstract The development of rapid and simple wall coating strategies for high‐efficiency electrophoretic separation DNA is crucial importance the successful implementation miniaturized polymeric analysis systems. In this report, we characterize compare different methods chemical modification poly(methyl methacrylate) (PMMA) surfaces application polymers. PMMA coated with 40 mol% diethylacrylamide 60 dimethylacrylamide are compared to first oxidized then hydroxypropylmethyl‐cellulose or...
Microfluidic synthesis of small and nearly-monodisperse liposomes is used to investigate the size-dependent passive transdermal transport nanoscale lipid vesicles. While large with diameters above 105 nm are found be excluded from deeper skin layers past stratum corneum, primary barrier nanoparticle transport, mean between 31–41 exhibit significantly enhanced penetration. Furthermore, multicolor fluorescence imaging reveals that smaller pass rapidly through corneum without vesicle rupture....
Extracellular vesicles (EVs), such as exosomes and microvesicles, are nonreplicating lipid bilayer particles shed by most cell types which have the potential to revolutionize development efficient delivery of clinical therapeutics. This article provides an introduction landscape EV-based vectors under for protein- nucleic acid-based We highlight some pressing measurement standardization challenges that limit translation EVs clinic. Current limiting drug lack of: standardized cell-based...
Temperature gradient focusing (TGF) is a recently developed technique for the simultaneous concentration and electrophoretic separation of ionic analytes in microfluidic channels. One drawback to TGF as it has previously been described limited peak capacity; only small number analyte peaks (approximately 2-3) can be simultaneously focused separated. In this paper, we report on variation method whereby bulk flow rate varied over time so that large sequentially focused, moved past fixed...
We present a new type of microfluidic connector that employs ring magnet on one side the chip and disc other to produce sealed connection between external tubing inlets or outlets devices. The connectors are low-cost, simple use assemble, reusable. used numerical (finite element) simulations in order optimize their geometry. Configurations achieve interfacial forces range 2 N 15 discussed. Several types gasket materials were explored. Finally, we demonstrate an application these device...