A5084492610- 3D Printing in Biomedical Research
- Microfluidic and Bio-sensing Technologies
- Microfluidic and Capillary Electrophoresis Applications
- Cancer Cells and Metastasis
- Innovative Microfluidic and Catalytic Techniques Innovation
- Nanofabrication and Lithography Techniques
- Advanced biosensing and bioanalysis techniques
- Advanced Radiotherapy Techniques
- Advanced Biosensing Techniques and Applications
- Cellular Mechanics and Interactions
- Cell Image Analysis Techniques
- Electrohydrodynamics and Fluid Dynamics
- Pancreatic function and diabetes
- Sphingolipid Metabolism and Signaling
- Prostate Cancer Diagnosis and Treatment
- Neuroscience and Neural Engineering
- Monoclonal and Polyclonal Antibodies Research
- Advanced Fluorescence Microscopy Techniques
- Gut microbiota and health
- Protein Degradation and Inhibitors
- Clostridium difficile and Clostridium perfringens research
- Radiation Dose and Imaging
- Wnt/β-catenin signaling in development and cancer
- Single-cell and spatial transcriptomics
- Biosensors and Analytical Detection
University of Washington
2020-2025
Center for Rheumatology
2024
Accuray (United States)
2008-2023
University of North Carolina at Chapel Hill
2011-2020
North Carolina State University
2010-2018
Communities In Schools of Orange County
2015-2016
University of California, Irvine
1999-2008
Beckman Laser Institute and Medical Clinic
1998-2008
University of California System
2006
Oak Ridge National Laboratory
2003
Poly(dimethylsiloxane) (PDMS)-based microfluidic devices are increasing in popularity due to their ease of fabrication and low costs. Despite this, there is a tremendous need for strategies rapidly easily tailor the surface properties these devices. We demonstrate one-step procedure covalently link polymers PDMS microchannels by ultraviolet graft polymerization. Acrylic acid, acrylamide, dimethylacrylamide, 2-hydroxylethyl acrylate, poly(ethylene glycol)monomethoxyl acrylate were grafted...
A microfluidic device is reported that integrated cell handling, rapid lysis, and electrophoretic separation detection of fluorescent cytosolic dyes. The function was demonstrated using Jurkat cells were loaded with the fluorogenic dyes − carboxyfluorescein diacetate, Oregon green carboxylic acid or Calcein AM. hydrodynamically transported from cell-containing reservoir to a region on where they focused then rapidly lysed an electric field. Complete lysis accomplished in <33 ms. hydrolyzed,...
Three-dimensional organoid culture has fundamentally changed the in vitro study of intestinal biology enabling novel assays; however, its use is limited because an inaccessible luminal compartment and challenges to data gathering a three-dimensional hydrogel matrix. Long-lived, self-renewing 2-dimensional (2-D) tissue cultured from primary colon cells not been accomplished.The surface matrix chemical factors that sustain 2-D mouse colonic human rectal epithelial cell monolayers with...
We demonstrate a simple procedure to coat the surfaces of enclosed PDMS microchannels by UV-mediated graft polymerization. In prior applications, only disassembled channels could be coated this method. This limited utility method coatings that easily and tightly seal with themselves. By preadsorbing photoinitiator onto surface microchannels, rate polymer formation at was greatly accelerated compared in solution. Thus, gel did not form lumen microchannels. benzophenone remained on even after...
The successful culture of intestinal organoids has greatly enhanced our understanding stem cell physiology and enabled the generation novel disease models. Although tremendous value, organoid systems have not yet fully recapitulated anatomy or in vivo epithelium. aim this work was to re-create an epithelium with a high density polarized crypts that respond physiologic manner addition growth factors, metabolites, cytokines basal luminal tissue surface as occurs vivo.
An oxygen gradient formed along the length of colonic crypts supports stem-cell proliferation at normoxic crypt base while supporting obligate anaerobe growth in anoxic lumen. Primary human epithelial cells derived from gastrointestinal stem were cultured within a device possessing materials tailored permeability to produce an oxygen-depleted luminal (0.8% ± 0.1% O2) and oxygen-rich basal (11.1% 0.5% compartment. This difference created stable across which remained viable properly polarized....
A new photografting method to micropattern a covalent surface modification on poly(dimethylsiloxane) (PDMS) provides advantages in simplicity and efficiency. To accomplish the entire process benchtop, PDMS was initially treated with benzophenone dissolved water/acetone mixture. This permitted limited diffusion of photoinitiator into surface. Polymerization acrylic acid initiated by exposure benzophenone-implanted UV radiation through photomask thin aqueous layer sandwiched between photomask....
The negative photoresist SU-8 has found widespread use as a material in the fabrication of microelectrical−mechanical systems (MEMS). Although been utilized structural for biological MEMS, number properties limit its application these bioanalytical devices. These attributes include brittleness, nonspecific adsorption biomolecules, and high fluorescence visible wavelengths. In addition, native is poor substrate cellular adhesion. Photoresists composed resins with epoxide side groups...
We use time-resolved imaging to examine the lysis dynamics of non-adherent BAF-3 cells within a microfluidic channel produced by delivery single highly-focused 540 ps duration laser pulses at λ = 532 nm. Time-resolved bright-field images reveal that pulsed microbeam results in formation laser-induced plasma followed shock wave emission and cavitation bubble formation. The confinement offered constrains substantially expansion significant deformation PDMS walls. To cell dispersal cellular...
Polystyrene (PS), a standard material for cell culture consumable labware, was molded into microstructures with high fidelity of replication by an elastomeric polydimethylsiloxane (PDMS) mold. The process simple, benchtop method based on soft lithography using readily available materials. key to successful replica molding this simple procedure relies the use solvent, example, gamma-butyrolactone, which dissolves PS without swelling PDMS solution added mold, and evaporation solvent...
The pathway and kinetics of inositol 1,4,5-trisphosphate (IP3) metabolism were measured in Xenopus laevis oocytes cytoplasmic extracts oocytes. Degradation microinjected IP3 intact was similar to that the containing comparable concentrations ([IP3]). rate route depended on [IP3] intracellular free Ca2+ concentration ([Ca2+]). At low (100 nm) high [Ca2+] (≥1 μm), IP3was metabolized predominantly by 3-kinase (3-kinase) with a half-life 60 s. As increased, polyphosphate 5-phosphatase...
Due to its potential for exquisite mass detection limits and resolving power, capillary electrophoresis is used biochemical measurements on single cells; however, accurate of many physiological parameters require sampling strategies that are considerably faster than those presently available. We have developed a laser-based technique lyse single, adherent, mammalian cells millisecond time scales. The cellular contents then introduced into where electrophoretic separation performed. Improved...
In the past decade, capillary electrophoresis has demonstrated increasing utility for quantitative analysis of single cells. New applications dynamic cellular properties demand sampling methods with sufficient temporal resolution to accurately measure these processes. particular, intracellular signaling pathways involving many enzymes can be modulated on subsecond time scales. We have developed a technique rapidly lyse an adherent mammalian cell using electrical pulse followed by efficient...
Translocation of membrane-impermeant molecules to the interior living cells is a necessity for many biochemical investigations. Myristoylation was studied as means introduce peptides into cells. Uptake myristoylated, fluorescent peptide efficient in B lymphocyte cell line BA/F3. In contrast, this resistant uptake cell-penetrating derived from TAT protein. BA/F3 cells, membrane association shown be rapid, reaching maximum within 30 min. Cellular lagged but occurred similar time frame....
Poly(dimethylsiloxane) (PDMS) is an attractive material for microelectrophoretic applications because of its ease fabrication, low cost, and optical transparency. However, use remains limited compared to that glass. A major reason the difficulty tailoring surface properties PDMS. We demonstrate UV grafting co-mixed monomers customize PDMS microfluidic channels in a simple one-step process. By co-mixing neutral monomer with charged different ratios, between those could be selected. Mixtures...
Fidaxomicin, which was recently approved for the treatment of Clostridium difficile-associated diarrhoea, demonstrates narrow-spectrum bactericidal activity via inhibition RNA polymerase. In this study we evaluated its inhibitory versus C. difficile toxin gene expression and production by quantifying mRNA protein.The effects fidaxomicin, major metabolite (OP-1118), vancomycin metronidazole on A B were determined assaying culture supernatants two isolates (ATCC 43255, a high-level...
The proliferative compartment of the colonic epithelium in vivo is located basal crypt where stem cells and transit-amplifying reside fuel rapid renewal non-proliferative epithelial as they migrate toward gut lumen. To mimic this tissue polarity, microstructures composed polydimethylsiloxane (PDMS) microwells Matrigel micropockets were used to guide a combined 2-dimensional (2D) 3-dimensional (3D) hybrid culture primary crypts isolated from murine colon. 2D 3D on planar PDMS surface was...
Cell-to-cell heterogeneity in lipid signaling underlies variations response and recurrence for many cancers, including leukemias. A highly parallel, miniaturized thin-layer chromatographic platform capable of assaying single cells was developed. Ultrasmall volumes (50 pL) standard fluorescent lipids were separated with excellent repeatability, reproducibility, limits detection. Sphingosine-cyanine 5 (Sph-Cy5) loaded into cells, the single-cell contents to identify Sph-Cy5 two metabolites,...