A5047551148- Cellular Mechanics and Interactions
- Force Microscopy Techniques and Applications
- Microfluidic and Bio-sensing Technologies
- Advanced Fluorescence Microscopy Techniques
- Microtubule and mitosis dynamics
- Orbital Angular Momentum in Optics
- Mass Spectrometry Techniques and Applications
- Lipid Membrane Structure and Behavior
- Metabolomics and Mass Spectrometry Studies
- Photochromic and Fluorescence Chemistry
- Blood properties and coagulation
- MicroRNA in disease regulation
- Cell Image Analysis Techniques
- 3D Printing in Biomedical Research
- Cellular transport and secretion
- Material Dynamics and Properties
- Tissue Engineering and Regenerative Medicine
- Biocrusts and Microbial Ecology
- Cell Adhesion Molecules Research
- Optical Imaging and Spectroscopy Techniques
- Mitochondrial Function and Pathology
- Polymer Surface Interaction Studies
- Cancer-related molecular mechanisms research
- Cholangiocarcinoma and Gallbladder Cancer Studies
- bioluminescence and chemiluminescence research
Johns Hopkins University
2004-2023
Johns Hopkins Medicine
1995-2023
University of Baltimore
2012
University of Illinois Urbana-Champaign
1993-1997
Duke University Hospital
1991-1993
Duke Medical Center
1991-1993
Duke University
1991-1993
We present a new method for measuring the linear viscoelastic shear moduli of complex fluids. Using photodiode detection laser light scattered from thermally excited colloidal probe sphere, we track its trajectory and extract using frequency-dependent Stokes-Einstein equation. Spectra obtained polyethylene oxide in water are excellent agreement with those found mechanically diffusing wave spectroscopy. Since only minute sample volumes required, this is well suited biomaterials high purity,...
Cell membranes often are patchy, composed of lateral domains. These domains may be formed by barriers within or on either side the membrane bilayer. Major histocompatibility complex (MHC) class 1 molecules that were transmembrane- (H-2Db) glycosylphosphatidylinositol (GPI)-anchored (Qa2) labeled with antibody-coated gold particles and moved across cell surface a laser optical tweezers until they encountered barrier, barrier-free path length (BFP). At room temperature, BFPs Qa2 H-2Db 1.7 +/-...
Filamentous actin (F-actin), one of the constituents cytoskeleton, is believed to be most important participant in motion and mechanical integrity eukaryotic cells. Traditionally, viscoelastic moduli F-actin networks have been measured by imposing a small strain quantifying resulting stress. The magnitude moduli, their concentration dependence dependence, as well nature (solid-like or liquid-like) uncross-linked F-actin, subjects debate. Although this paper helps resolve debate establishes...
CD8 + T cells are specialized of the adaptive immune system capable finding and eliminating pathogen-infected cells. To date it has not been possible to observe destruction any pathogen by in vivo. Here we demonstrate a technique for imaging killing liver-stage malaria parasites bearing transgenic cell receptor specific parasite epitope. We report several features that have described vitro analysis process, chiefly formation large clusters effector around infected hepatocytes. The requires...
MicroRNA (miRs) have emerged as salient regulators in cancer homeostasis and, recently, putative therapeutics. Cholangiocarcinomas (CCA) are aggressive cancers with survival usually measured months. mRNA arrays followed by pathway analysis revealed that miR-494 is a major modulator of the cell cycle progression from gap 2 (G₂) to mitosis (M). We performed fluorescence activated sorting (FACS) well differential interference contrast (DIC) microscopy, and confirmed induces significant arrest...
We have developed microtubule binding and motility assays for Cin8p, a kinesin-related mitotic spindle motor protein from <i>Saccharomyces cerevisiae</i>. The methods examine Cin8p rapidly purified crude yeast cell extracts. created recombinant form of <i>CIN8</i> that fused the biotin carrying polypeptide pyruvate carboxylase to carboxyl terminus Cin8p. This was biotinated in cells provided activity <i>in vivo</i>. Avidin-coated glass surfaces were used specifically bind Microtubules bound...
We demonstrate a quantitative optical scatter imaging (OSI) technique, based on Fourier filtering, for detecting alterations in the size of particles with wavelength-scale dimensions. generate our image by taking ratio images collected at high and low numerical aperture central dark-field microscopy. Such an spatially encodes wide to narrow angle hence provides measure local particle size. validated OSI sphere suspensions live cells. In cells, revealed biochemically induced morphological...
Biofabricated mass-producible arteries containing layered and aligned cells matrix exhibit enhanced cellular function.
Our detailed measurements of the movements kinesin- and dynein-coated latex beads have revealed several important features motors which underlie basic mechanical aspects mechanisms motor movements. Kinesin-coated will move along paths individual microtubule protofilaments with high fidelity pause at 4 nm intervals axis under low ATP conditions. In contrast, cytoplasmic laterally across many as they travel microtubule, without any regular pauses, suggesting that kinesin-coated are not an...
Cell cortices rearrange dynamically to complete cytokinesis, crawlin response chemoattractant, build tissues, and make neuronal connections. Highly enriched in the cell cortex, actin, myosin II, actin crosslinkers facilitate cortical movements. Because behavior is consequence of nanoscale biochemical events, it essential probe cortex at this level. Here, we use high-resolution laser-based particle tracking examine how II mechanochemistry dynacortin-mediated crosslinking control dynamics...
Abstract Here, the authors report that co‐crystallization of fluorophores with matrix‐assisted laser desorption/ionization (MALDI) imaging matrices significantly enhances fluorophore brightness up to 79‐fold, enabling amplification innate tissue autofluorescence. This discovery facilitates FluoMALDI, same biological sample by both fluorescence microscopy and MALDI imaging. The approach combines high spatial resolution specific labeling capabilities inherently multiplexed, versatile new...
Effects of 3D confinement on cellular growth and matrix assembly are important in tissue engineering, developmental biology, regenerative medicine. Polydimethylsiloxane wells with varying anisotropy microfabicated using soft‐lithography. Microcontact printing bovine serum albumin is used to block cell adhesion surfaces between wells. The orientations fibroblast stress fibers, microtubules, fibronectin fibrils examined 1 day after seeding laser scanning confocal microscopy, quantified a...