Transgenic mice expressing a cameleon fluorescent Ca2+ indicator in astrocytes and Schwann cells allow study of glial cell Ca2+ signals in situ and in vivo.
AuthorsAtkin SD, Patel S, Kocharyan A, Holtzclaw LA, Weerth SH, Schram V, Pickel J, Russell JT,
JournalJ Neurosci Methods
PubMed ID19454294
'Glial cell Ca2+ signals play a key role in glial-neuronal and glial-glial network communication. Numerous studies have thus far utilized cell-permeant and injected Ca2+ indicator dyes to investigate glial Ca2+ signals in vitro and in situ. Genetically encoded fluorescent Ca2+ indicators have emerged as novel probes for investigating cellular Ca2+ ... More
Optimizing a waveguide-based sandwich immunoassay for tumor biomarkers: evaluating fluorescent labels and functional surfaces.
AuthorsMukundan H, Xie H, Anderson AS, Grace WK, Shively JE, Swanson BI,
JournalBioconjug Chem
PubMed ID19173652
'The sensor team at the Los Alamos National Laboratory has developed a waveguide-based optical biosensor for the detection of biomarkers associated with disease. We have previously demonstrated the application of this technology to the sensitive detection of carcinoembryonic antigen in serum and nipple aspirate fluid from breast cancer patients. In ... More
Targeted cellular delivery of quantum dots loaded on and in biotinylated liposomes.
AuthorsSigot V, Arndt-Jovin DJ, Jovin TM,
JournalBioconjug Chem
PubMed ID20715851
'We describe the preparation, biophysical characterization, and receptor-mediated cellular internalization of biotinylated lipid particles (BLPs) loaded on the surface and internally with two distinct (colors) of quantum dot (QD) probes. BLPs were formulated with 1.4 and 2.7 mol % PEG-lipids containing either a fusogenic or pH-sensitive lipid to promote bilayer ... More
Quantum dot photon statistics measured by three-dimensional particle tracking.
AuthorsMcHale K, Berglund AJ, Mabuchi H
JournalNano Lett
PubMed ID17949048
'We present an instrument for performing correlation spectroscopy on single fluorescent particles while tracking their Brownian motion in three dimensions using real-time feedback. By tracking CdSe/ZnS quantum dots in water (diffusion coefficient approximately 20 mum2/s), we make the first measurements of photon antibunching (at approximately 10 ns) on single fluorophores ... More
Bioconjugation of the estrogen receptor hER(a) to a quantum dot dye for a controlled immobilization on a SiO(2) surface.
AuthorsCherkouk C, Rebohle L, Skorupa W,
JournalJ Colloid Interface Sci
PubMed ID21216405
'We investigated the immobilization of the estrogen receptor hER(a) on silanized SiO(2) surfaces for biosensor applications. The conjugation of the estrogen receptor hER(a) to the quantum dot dye QD655 was achieved. In order to obtain an optimal immobilization of the estrogen receptor hER(a) on the functionalized SiO(2) surface, the bioconjugate ... More
In vivo real-time, multicolor, quantum dot lymphatic imaging.
AuthorsKosaka N, Ogawa M, Sato N, Choyke PL, Kobayashi H,
JournalJ Invest Dermatol
PubMed ID19536144
'The lymphatic network is complex and difficult to visualize in real-time in vivo. Moreover, the direction of flow within lymphatic networks is often unpredictable especially in areas with well-developed ' ... More
Cellular imaging and surface marker labeling of hematopoietic cells using quantum dot bioconjugates.
AuthorsZheng J, Ghazani AA, Song Q, Mardyani S, Chan WC, Wang C
JournalLab Hematol
PubMed ID16751137
'Semiconductor quantum dots (qdots) are emerging as a new class of fluorescent labels. The unique optical properties of qdots make them appealing in laboratory diagnosis; however, qdot-based probes remain to be developed and evaluated for clinical laboratory applications. In this study, 2 different approaches were employed to label hematopoietic cells ... More
Simultaneous multicolor imaging of five different lymphatic basins using quantum dots.
AuthorsKobayashi H, Hama Y, Koyama Y, Barrett T, Regino CA, Urano Y, Choyke PL
JournalNano Lett
PubMed ID17530812
Quantum dots can be used to perform multicolor images with high fluorescent intensity and are of a nanosize suitable for lymphatic imaging via direct interstitial injection. Here simultaneous multicolor in vivo wavelength-resolved spectral fluorescence lymphangiography is shown using five quantum dots with similar physical sizes but different emission spectra. This ... More
Variables influencing interactions of untargeted quantum dot nanoparticles with skin cells and identification of biochemical modulators.
AuthorsRyman-Rasmussen JP, Riviere JE, Monteiro-Riviere NA
JournalNano Lett
PubMed ID17408303
Skin cells (NHEK) take up untargeted quantum dots (QD) with surface polyethylene glycol (PEG), amines, and carboxylic acids, but the mechanisms are unknown. Time courses of QD-NHEK interactions were determined and effects of QD surface coating, temperature, culture medium supplements and inhibitors of the cell cycle and endocytosis identified. The ... More
Cholera toxin B conjugated quantum dots for live cell labeling.
Cholera toxin subunit B (CTB)--quantum dot conjugates were developed for labeling mammalian cells. The conjugates were internalized by all tested cell lines into small vesicles dispersed throughout the cytoplasm, while commercially available polyarginine conjugates rapidly accumulated in large perinuclear endosomes. Although a large proportion of CTB conjugates eventually also accumulated ... More
Sentinel lymph node imaging using quantum dots in mouse tumor models.
We demonstrate that quantum dots injected into two model tumors rapidly migrate to sentinel lymph nodes. PEG-coated quantum dots having terminal carboxyl, amino, or methoxyl groups all migrated from the tumor to surrounding lymph nodes similarly. Passage from the tumor through lymphatics to adjacent nodes could be visualized dynamically through ... More
Quantum dot hybrid gel blotting: a technique for identifying quantum dot-protein/protein-protein interactions.
AuthorsVu TQ, Liu HY,
JournalMethods Mol Biol
PubMed ID19488713
We describe an alternative to the molecular biology technique of polyacrylamide gel electrophoresis-based Western blotting and immunoprecipitation, which is an extensively used method for separating target proteins from complex cellular mixtures and for identification of protein expression and protein-protein interactions. This novel method, called quantum dot (QD) hybrid gel blotting, ... More
She3p binds to the rod of yeast myosin V and prevents it from dimerizing, forming a single-headed motor complex.
AuthorsHodges AR, Krementsova EB, Trybus KM,
JournalJ Biol Chem
PubMed ID18175803
Vertebrate myosin Va is a dimeric processive motor that walks on actin filaments to deliver cargo. In contrast, the two class V myosins in budding yeast, Myo2p and Myo4p, are non-processive (Reck-Peterson, S. L., Tyska, M. J., Novick, P. J., and Mooseker, M. S. (2001) J. Cell Biol. 153, 1121-1126). ... More
Dynamics and mechanisms of quantum dot nanoparticle cellular uptake.
AuthorsXiao Y, Forry SP, Gao X, Holbrook RD, Telford WG, Tona A,
JournalJ Nanobiotechnology
PubMed ID20550705
ABSTRACT: BACKGROUND: The rapid growth of the nanotechnology industry and the wide application of various nanomaterials have raised concerns over their impact on the environment and human health. Yet little is known about the mechanism of cellular uptake and cytotoxicity of nanoparticles. An array of nanomaterials has recently been introduced ... More
Mechanisms of quantum dot nanoparticle cellular uptake.
AuthorsZhang LW, Monteiro-Riviere NA,
JournalToxicol Sci
PubMed ID19414515
Due to the superior photoemission and photostability characteristics, quantum dots (QD) are novel tools in biological and medical applications. However, the toxicity and mechanism of QD uptake are poorly understood. QD nanoparticles with an emission wavelength of 655 nm are ellipsoid in shape and consist of a cadmium/selenide core with ... More
Bioconjugated quantum dots for multiplexed and quantitative immunohistochemistry.
AuthorsXing Y, Chaudry Q, Shen C, Kong KY, Zhau HE, Chung LW, Petros JA, O'Regan RM, Yezhelyev MV, Simons JW, Wang MD, Nie S
JournalNat Protoc
PubMed ID17546006
Bioconjugated quantum dots (QDs) provide a new class of biological labels for evaluating biomolecular signatures (biomarkers) on intact cells and tissue specimens. In particular, the use of multicolor QD probes in immunohistochemistry is considered one of the most important and clinically relevant applications. At present, however, clinical applications of QD-based ... More
Surface coatings determine cytotoxicity and irritation potential of quantum dot nanoparticles in epidermal keratinocytes.
AuthorsRyman-Rasmussen JP, Riviere JE, Monteiro-Riviere NA
JournalJ Invest Dermatol
PubMed ID16902417
Quantum dot (QD) nanoparticles have potential applications in nanomedicine as drug delivery vectors and diagnostic agents, but the skin toxicity and irritation potential of QDs are unknown. Human epidermal keratinocytes (HEKs) were used to assess if QDs with different surface coatings would cause differential effects on HEK cytotoxicity, proinflammatory cytokine ... More
Penetration of intact skin by quantum dots with diverse physicochemical properties.
AuthorsRyman-Rasmussen JP, Riviere JE, Monteiro-Riviere NA
JournalToxicol Sci
PubMed ID16443688
Skin is the largest organ of the body and is a potential route of exposure to engineered nanomaterials, but the permeability of the skin to these nanomaterials is unknown. We selected commercially available quantum dots (QD) of two core/shell sizes and shapes and three different surface coatings to determine if ... More