Binding of muscimol-conjugated quantum dots to GABAC receptors.
AuthorsGussin HA, Tomlinson ID, Little DM, Warnement MR, Qian H, Rosenthal SJ, Pepperberg DR,
JournalJ Am Chem Soc
PubMed ID17147380
'Functionalization of highly fluorescent CdSe/ZnS core-shell nanocrystals (quantum dots, qdots) is an emerging technology for labeling cell surface proteins. We have synthesized a conjugate consisting of approximately 150-200 muscimols (a GABA receptor agonist) covalently joined to the qdot via a poly(ethylene glycol) (PEG) linker (approximately 78 ethylene glycol units) and ... More
Fluorescent cell barcoding in flow cytometry allows high-throughput drug screening and signaling profiling.
AuthorsKrutzik PO, Nolan GP
JournalNat Methods
PubMed ID16628206
'Flow cytometry allows high-content, multiparameter analysis of single cells, making it a promising tool for drug discovery and profiling of intracellular signaling. To add high-throughput capacity to flow cytometry, we developed a cell-based multiplexing technique called fluorescent cell barcoding (FCB). In FCB, each sample is labeled with a different signature, ... More
Water-soluble quantum dots for multiphoton fluorescence imaging in vivo.
AuthorsLarson DR, Zipfel WR, Williams RM, Clark SW, Bruchez MP, Wise FW, Webb WW
JournalScience
PubMed ID12775841
'The use of semiconductor nanocrystals (quantum dots) as fluorescent labels for multiphoton microscopy enables multicolor imaging in demanding biological environments such as living tissue. We characterized water-soluble cadmium selenide-zinc sulfide quantum dots for multiphoton imaging in live animals. These fluorescent probes have two-photon action cross sections as high as 47,000 ... More
The dynamic control of kiss-and-run and vesicular reuse probed with single nanoparticles.
AuthorsZhang Q, Li Y, Tsien RW,
JournalScience
PubMed ID19213879
'Vesicular secretion of neurotransmitter is essential for neuronal communication. Kiss-and-run is a mode of membrane fusion and retrieval without the full collapse of the vesicle into the plasma membrane and de novo regeneration. The importance of kiss-and-run during efficient neurotransmission has remained in doubt. We developed an approach for loading ... More
Targeted tumor cell internalization and imaging of multifunctional quantum dot-conjugated immunoliposomes in vitro and in vivo.
AuthorsWeng KC, Noble CO, Papahadjopoulos-Sternberg B, Chen FF, Drummond DC, Kirpotin DB, Wang D, Hom YK, Hann B, Park JW,
JournalNano Lett
PubMed ID18712930
'Targeted drug delivery systems that combine imaging and therapeutic modalities in a single macromolecular construct may offer advantages in the development and application of nanomedicines. To incorporate the unique optical properties of luminescent quantum dots (QDs) into immunoliposomes for cancer diagnosis and treatment, we describe the synthesis, biophysical characterization, tumor ... 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
Quantum dots provide an optical signal specific to full collapse fusion of synaptic vesicles.
AuthorsZhang Q, Cao YQ, Tsien RW,
JournalProc Natl Acad Sci U S A
PubMed ID17968015
Synaptic vesicles are responsible for releasing neurotransmitters and are thus essential to brain function. The classical mode of vesicle recycling includes full collapse of the vesicle into the plasma membrane and clathrin-mediated regeneration of a new vesicle. In contrast, a nonclassical mode known as ... 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
Surface modification to reduce nonspecific binding of quantum dots in live cell assays.
AuthorsBentzen EL, Tomlinson ID, Mason J, Gresch P, Warnement MR, Wright D, Sanders-Bush E, Blakely R, Rosenthal SJ
JournalBioconjug Chem
PubMed ID16287246
Nonspecific binding is a frequently encountered problem with fluorescent labeling of tissue cultures when labeled with quantum dots. In these studies various cell lines were examined for nonspecific binding. Evidence suggests that nonspecific binding is related to cell type and may be significantly reduced by functionalizing quantum dots with poly(ethylene ... More
Peptide-conjugated quantum dots: imaging the angiotensin type 1 receptor in living cells.
Peptide-quantum dot conjugates have been prepared by attaching angiotensin II (Ang II) to cadmium selenide/zinc sulfide core-shell nanocrystals using an 1-[3-(Dimethyamino)propyl]-3-ethylcarbo diimide hydrochloride (EDC) coupling. These conjugates have been used to image angiotensin I-expressing Chinese hamster ovary (CHO) cells in vitro. When CHO cells were incubated with Ang II before ... 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
GABAC receptor binding of quantum-dot conjugates of variable ligand valency.
AuthorsGussin HA, Tomlinson ID, Muni NJ, Little DM, Qian H, Rosenthal SJ, Pepperberg DR,
JournalBioconjug Chem
PubMed ID20715850
Highly fluorescent CdSe quantum dots (qdots) can serve as a platform for tethering multiple copies of a receptor-targeted ligand, affording study of how the level of multivalency affects receptor binding. We previously showed that qdots conjugated with long PEG chains terminated by muscimol, a known GABA(C) agonist, exhibit specific binding ... More
Determination of absolute protein numbers in single synapses by a GFP-based calibration technique.
AuthorsSugiyama Y, Kawabata I, Sobue K, Okabe S,
JournalNat Methods
PubMed ID16118638
To build a quantitative model of molecular organization of neurons, it is essential to have information about the number of protein molecules at individual synapses. Here we developed a method to estimate absolute numbers of individual proteins at actual excitatory synapses by calibrating the fluorescence intensity of microspheres with single ... More
Use of quantum dot luminescent probes to achieve single-cell resolution of human oral bacteria in biofilms.
AuthorsChalmers NI, Palmer RJ, Du-Thumm L, Sullivan R, Shi W, Kolenbrander PE
JournalAppl Environ Microbiol
PubMed ID17114321
Oral biofilms are multispecies communities, and in their nascent stages of development, numerous bacterial species engage in interspecies interactions. Better insight into the spatial relationship between different species and how species diversity increases over time can guide our understanding of the role of interspecies interactions in the development of the ... More