A near-infrared fluorescence dye for sensitive detection of hydrogen sulfide in serum

Cy-Cl, a cationic near-infrared cyanine dye, readily reacts with hydrogen sulfide (H2S) via nucleophilic thiolation to give dose-dependent ‘turn-off’ fluorescence and colorimetric read-out, allowing selective detection of low levels of H2S in serum and imaging of mitochondrial H2S in living cells.This work was supported by Grants from NSF China 21272196, 973 Program 2013CB933901, NFFTBS (J1210014), the National Science Foundation of Fujian Province (2011J06004), and a open project grant from State Key Laboratory of C hemo/biosensing and Chemometrics (2012002); Dr. J. Han was supported by Grants from NSF China 31221065, 91029304, 81061160512 and 973 Program 2009CB522200

Imaging of intracellular acidic compartments with a sensitive rhodamine based fluorogenic pH sensor

The parameters of intracellular acidic compartments are altered in apoptosis, autophagy, cancer metastasis, etc. Low background and selective staining of lysosomes and autophagosomes was achieved with N-(rhodamine 6G)-lactam-ethylenediamine (R6G-EDA) which fluoresces in acidic vesicles via pH mediated ring opening of the intramolecular lactam. Long retention time of R6G-EDA in lysosomes and its exceptional stability against photo-bleaching allow full time tracking of lysosome morphology changes in tumor necrosis factor-alpha (TNF-alpha) triggered cell death, suggesting its utility for acidic vesicle studies in cell biology.NSF China[20802060, 21072162, 30830092, 30921005, 91029304, 81061160512]; Xiamen University[2011121020]; 973 program[2009CB522200

Chromogenic and fluorogenic detection of a nerve agent simulant with a rhodamine-deoxylactam based sensor

A chromogenic and fluorogenic detection of a nerve agent simulant was developed based on diethyl chlorophosphate triggered tandem phosphorylation and intramolecular cyclization of N-(rhodamine B)-deoxylactam-2-aminoethanol.NSF China[20802060, 21072162]; Natural Science Foundation of Fujian Province of China[2011J06004]; Fundamental Research Funds for the Central Universities[2011121020

Chromo-fluorogenic detection of aldehydes with a rhodamine based sensor featuring an intramolecular deoxylactam

A chromogenic and fluorogenic detection of aldehydes was achieved via analyte triggered opening of the deoxylactam of N-(rhodamine B)-deoxylactam-ethylenediamine (dRB-EDA). The utility of the sensor was demonstrated by fluorescent labeling of aldehyde-displaying sialoproteins on cell surfaces.NSF China[20802060, 21072162, 30830092, 30921005, 91029304, 81061160512]; Natural Science Foundation of Fujian Province of China[2011J06004]; Fundamental Research Funds for the Central Universities[2011121020]; 973 program[2009CB522200

Dual colored mesoporous silica nanoparticles with pH activable rhodamine-lactam for ratiometric sensing of lysosomal acidity

Alteration of lysosome acidity has been implicated in many biological events ranging from apoptosis to cancer metastasis, etc. Mesoporous silica nanoparticles doped with acid activable rhodamine-lactam and fluorescein isothiocyanate (FITC) were developed for ratiometric sensing of lysosomal pH changes in live cells with flow cytometry.NSF China[20802060, 21072162, 30830092, 30921005, 91029304, 81061160512]; Fundamental Research Funds for the Central Universities[2011121020]; 973 program[2009CB522200

Multivalent mannose-displaying nanoparticles constructed from poly{styrene-co-[(maleic anhydride)-alt-styrene]}

Micellar mannose nanoparticles were constructed from poly{styrene-co-[(maleic anhydride)alt-styrene]} with fluorophores or quenchers doped into the hydrophobic inner cores, allowing the direct monitoring of multivalent lectin-glycan interactions. The mannose-displaying nanoparticles bind Con A and sperm surface lectins with high affinity, suggesting their broad utility for modulating protein-carbohydrate interaction mediated cell surface biology.National Natural Science Foundation of China [20842001, 20802060]; [2006AA02Z164

Visual and fluorogenic detection of a nerve agent simulant via a Lossen rearrangement of rhodamine-hydroxamate

A visual and fluorogenic detection method for a nerve agent simulant was developed based on a Lossen rearrangement of rhodamine-hydroxamate, in the presence of diethyl chlorophosphate, under alkaline conditions.Molecular Cloning Laboratories (South San Francisco, CA) ; National Natural Science Foundation of China [20802060

A targetable acid-responsive micellar system for signal activation based high performance surgical resolution of tumors

973 program [2013CB93390]; NSF China [21272196, 21072162, 30830092, 30921005, 91029304, 81061160512]; PCSIRT; Fundamental Research Funds for the Central Universities [2011121020]Tumor-reporting probes are valuable to guide surgical resection of tumor foci elusive to visual inspection. As tumors display distinct arrays of lectins, we herein report the construction and screening of a panel of glycan-displaying smart micelles for tumor illumination in mice. These micelles consist of cores of rhodamine-sultam (RST) responsive to lysosomal acidity and a corona of poly[styrene-alter-(maleic acid)] glycosylated with D-glucosamine, D-mannosamine or D-galactosamine. These nanoscale micelles are nonfluorescent extracellularly and become luminescent within acidic lysosomes, enabling optical tracking of tumor endocytosis of the micelles. In vivo screening revealed high-efficiency uptake and fluorescence activation of galactosylated micelles (RST@P-Gal) by subcutaneous tumor and disseminated liver tumor foci with diameters of 0.1-10 mm, which is significantly below minimal residual cancer (a minimum of 1 cm clearance). This system is readily adapted to illuminate different tumors by expanding the diversity of glycans on the shell. Given the robustness and high performance of this system, lectin-targeted responsive micelles are attractive for diagnosis or surgical ablation of tumors

A photothermal cell viability-reporting theranostic nanoprobe for intraoperative optical ablation and tracking of tumors

973 program [2013CB93390]; NSFC [21272196, 81071182]; Fundamental Research Funds for the Central Universities [2012121018]; NSF of Fujian Province [2011J06004]; PCSIR; Medical Innovation Foundation of Fujian [2009-CXB-46]A photothermal pH-reporting nanoprobe was developed for intraoperative tumor detection by "turn-on'' fluorescence of the probe inside viable tumor cells, photothermal tumor therapy, and in situ monitoring of tumor killing by non-fluorescence of the probe in damaged cells

A fluorescently labelled sialic acid for high performance intraoperative tumor detection

973 program [2013CB93390]; NSF China [21272196, 30830092, 30921005, 91029304, 81061160512]; PCSIRT; Fundamental Research Funds for the Central Universities [2011121020]Surgical resection is widely used for tumor treatment, necessitating approaches for the precise locating of elusive tumor foci. We report the high performance detection of tumors in mice with fluorescein-isothiocyanate (FITC) labelled sialic acid (FITC-SA), a fluorescent monosaccharide with low cytoxicity. Analysis of mice intravenously injected with FITC-SA revealed high target-to-background fluorescence ratios in subcutaneous tumors and liver tumor implants with 0.2-5 mm diameters, which are significantly below the clinical threshold of minimal residual cancer (similar to 1 cm clearance). Extracellular FITC-SA is quickly cleared from circulation whereas the intracellular FITC-SA could be metabolically incorporated into glycoproteins via a cellular sialylation pathway. Compared with FITC-SA-laden nanoparticles, free FITC-SA is preferentially and quickly taken up by tumors in mice and displays high tumor-to-background signal contrast, suggesting the potential for fluorescence directed surgical ablation of tumors