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Fluorescent imaging

Doron Shabat, Samer Gnaim, Anna Scomparin, Sayantan Das, Ronit Satchi-Fainaro
The majority of theranostic prodrugs reported so far relay information through a fluorogenic response generated upon release of the active chemotherapeutic agent. A chemiluminescence detection mode offers significant advantages over fluorescence, mainly due to the superior signal-to-noise ratio of chemiluminescence. Here we report the design and synthesis of the first theranostic prodrug monitored by a chemiluminescence diagnostic mode. As a representative model we prepared a prodrug from the chemotherapeutic monomethyl auristatin E designed for activation by β-galactosidase...
May 22, 2018: Angewandte Chemie
Geertje van der Horst, Maaike van der Mark, Henry Cheung, Gabri van der Pluijm
Current treatments of advanced prostate cancer only marginally increase overall survival and can be regarded as predominantly palliative. Hence, there is an urgent need for novel therapeutic strategies for the treatment of primary tumors and, more importantly perhaps, for the prevention of tumor progression and metastasis formation. Clinically relevant preclinical models are therefore urgently needed. An ideal, clinically relevant preclinical model would mimic the genetic and phenotypic changes that occur at the different stages of human prostate cancer progression and subsequent metastasis...
2018: Methods in Molecular Biology
Weiwei An, Ralph P Mason, Alexander R Lippert
Chemiluminescence imaging offers a low background and high sensitivity approach to imaging analytes in living cells and animals. Intensity-based measurements have been developed, but require careful consideration of kinetics, probe localization, and fluctuations in quantum yield, all of which complicate quantification. Here, we report a ratiometric strategy for quantitative chemiluminescence imaging of pH. The strategy relies on an energy transfer cascade of chemiluminescence emission from a spiroadamantane 1,2-dioxetane to a ratiometric pH indicator via fluorescent dyes in Enhancer solutions...
May 22, 2018: Organic & Biomolecular Chemistry
Jiong Li, Xuandong Wang, Dongye Zheng, Xinyi Lin, Zuwu Wei, Da Zhang, Zhuanfang Li, Yun Zhang, Ming Wu, Xiaolong Liu
Theranostic nanoprobes integrated with dual-modal imaging and therapeutic functions, such as photodynamic therapy (PDT), have exhibited significant potency in cancer treatments due to their high imaging accuracy and non-invasive advantages for cancer elimination. However, biocompatibility and highly efficient accumulation of these nanoprobes in tumor are still unsatisfactory for clinical application. In this study, a photosensitizer -loaded magnetic nanobead with surface further coated with a layer of cancer cell membrane (SSAP-Ce6@CCM) was designed to improve the biocompatibility and cellular uptake and ultimately achieve enhanced MR/NIR fluorescence imaging and PDT efficacy...
May 22, 2018: Biomaterials Science
Hesheng Victor Xu, Xinting Zheng, Yanli Zhao, Yen Nee Tan
Natural amino acids possess side chains with different functional groups (R groups), which make them excellent precursors for programmable synthesis of biomolecule-derived nanodots (bio-dots) with desired properties. Herein, we reported the first systematic study to uncover the material design rules of bio-dots synthesis from 20 natural α-amino acids via a green hydrothermal approach. The as-synthesized amino acids bio-dots (AA-dots) are comprehensively characterised to establish a structure-properties relationship between the amino acid precursors and the corresponding photoluminescent properties of AA-dots...
May 22, 2018: ACS Applied Materials & Interfaces
Anwesha Sarkar, Yuanchang Zhao, Yongliang Wang, Xuefeng Wang
Integrin-transmitted cellular forces are crucial mechanical signals regulating a vast range of cell functions. Although various methods have been developed to visualize and quantify cellular forces at the cell-matrix interface, a method with high performance and low technical barrier is still in demand. Here we developed force-activatable coating (FAC) which can be simply coated on regular cell culture apparatus's surfaces by physical adsorption, and turn these surfaces to force reporting platforms that enable cellular force mapping directly by fluorescence imaging...
May 22, 2018: Physical Biology
Feiyan Liu, Zhen Wang, Wenli Wang, Jian-Guang Luo, Lingyi Kong
γ-Glutamyltranspeptidase (GGT) plays critical roles in regulating various physiological/pathophysiological processes including the intracellular redox homeostasis. However, an effective fluorescent probe for dissecting the relationships between GGT and oxidative stress in vivo remains largely unexplored. Herein, we present a light-up fluorescent probe (DCDHF-Glu) with long wavelength emission (613 nm) for the highly sensitive and selective detection of GGT using dicyanomethylenedihydrofuran derivative as the fluorescent reporter and γ-glutamyl group as the enzyme-active trigger...
May 22, 2018: Analytical Chemistry
Mohamad Sukri Mohamad Yusof, Mohd Hafiz Dzarfan Othman, Azeman Mustafa, Mukhlis Abdul Rahman, Juhana Jaafar, Ahmad Fauzi Ismail
Palm oil fuel ash (POFA) is an agricultural waste which was employed in this study to produce novel adsorptive ceramic hollow fibre membranes. The membranes were fabricated using phase inversion-based extrusion technique and sintered at 1150 °C. The membranes were then evaluated on their ability to adsorb cadmium (Cd(II)). These membranes were characterised using (nitrogen) N2 adsorption-desorption analysis, field emission scanning electron microscopy-energy-dispersive X-ray spectroscopy (FESEM-EDX) mapping, X-ray fluorescence (XRF), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) analyses while adsorptivity activity was examined by batch adsorption studies...
May 21, 2018: Environmental Science and Pollution Research International
Chang-Ye Hui, Yan Guo, Wen Zhang, Xian-Qing Huang
Real-time quantification of recombinant proteins is important in studies on fermentation engineering, cell engineering, etc. Measurement of the expression level of heterologous proteins in bacterial fermentation broth has traditionally relied on time-consuming and labor-intensive procedures, such as polyacrylamide gel electrophoresis, immunoblot analysis, and biological activity assays. We describe a simple, fast, and high sensitive assay for detecting heterologous proteins production in bacteria either at the overall level (fluorescence spectrophotometry) or at the individual level (fluorescence microscopic image) in this study...
May 21, 2018: AMB Express
Yang Li, Huabing Zhang, Yilin Chen, Jinyuan Ma, Jinyan Lin, Yinying Zhang, Zhongxiong Fan, Guanghao Su, Liya Xie, Xuan Zhu, Zhenqing Hou
Combinational cancer therapy has been considered as a promising strategy to achieve synergetic therapeutic effects and suppression of multidrug resistance. Herein, we adopted a combination of methotrexate (MTX), an antimetabolite acting on cytoplasm, and 10-hydroxycamptothecin (HCPT), an alkaloid acting on nuclei, to treat cancer. Given the different solubilities, membrane permeabilities, and anticancer mechanisms of both drugs, we developed a dual-targeting delivery system based on 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-hyaluronic acid (a principal ligand of CD44 receptors)-MTX (a selective ligand of folate receptors) nanoparticles, which was exploited to carry HCPT-MTX conjugate for synergistically boosting dual-drug co-delivery...
May 22, 2018: Biomaterials Science
Li Wang, Eric Lin, Mary J Johansen, Timothy Madden, Edward Felix, Karen S Martirosyan, Steven J Frank
The novel positive-contrast magnetic resonance imaging (MRI) marker C4 consists of an aqueous solution of cobalt chloride (CoCl2 ) complexed with the chelator N-acetylcysteine (NAC). We evaluated whether the presence of C4 or its components would produce reactive oxygen species (ROS, including hydroxyl, peroxyl, or other reactive oxygen species) in cultured cells. Human cancer or normal cells were incubated with 1% (w/v) CoCl2 ·6H2 O or 2% NAC or a combination of both (1% CoCl2 ·6H2 O : 2% NAC in an aqueous solution, abbreviated as Co : NAC) in the presence or absence of H2 O2 ...
2018: Journal of Toxicology
Onur Sen, Adrian T Saurin, Jonathan M G Higgins
SiR-Hoechst (SiR-DNA) is a far-red fluorescent DNA probe being used widely for time-lapse imaging of living cells that is reported to be minimally toxic at concentrations as high as 10-25 µM. However, measuring nuclear import of Cyclin B1, inhibition of mitotic entry, and the induction of γH2AX foci in cultured human cells reveals that SiR-Hoechst induces DNA damage responses and G2 arrest at concentrations well below 1 µM. SiR-Hoechst is useful for live cell imaging, but it should be used with caution and at the lowest practicable concentration...
May 21, 2018: Scientific Reports
Bingqiong Wang, Yameng Sun, Jialing Zhou, Xiaoning Wu, Shuyan Chen, Shanshan Wu, Hui Liu, Tailing Wang, Xiaojuan Ou, Jidong Jia, Hong You
Hepatitis B (HBV)-related fibrosis can be reversed after effective antiviral therapy. However, detailed changes of collagen characteristics during fibrosis regression remain unclear. Paired biopsy samples obtained from chronic hepatitis B patients were imaged with second harmonic generation/two photon excitation fluorescence (SHG/TPEF)-based microscopy to identify and quantify collagen features in portal, septal, and fibrillar areas. According to the changes of Ishak stage and qFibrosis score, a total of 117 patients with paired liver biopsy appeared to have four different outcomes after 78-week antiviral therapy: fast reverse (9%), reverse (63%), stable (15%), or progress (13%) on fibrosis...
May 21, 2018: Modern Pathology: An Official Journal of the United States and Canadian Academy of Pathology, Inc
Sheng Xiao, Hua-An Tseng, Howard Gritton, Xue Han, Jerome Mertz
Fast volumetric microscopy is required to monitor large-scale neural ensembles with high spatio-temporal resolution. Widefield fluorescence microscopy can image large 2D fields of view at high resolution and speed while remaining simple and costeffective. A focal sweep add-on can further extend the capacity of widefield microscopy by enabling extended-depth-of-field (EDOF) imaging, but suffers from an inability to reject out-of-focus fluorescence background. Here, by using a digital micromirror device to target only in-focus sample features, we perform EDOF imaging with greatly enhanced contrast and signal-to-noise ratio, while reducing the light dosage delivered to the sample...
May 21, 2018: Scientific Reports
Yongjun Hu, Feifeng Song, Huidi Jiang, Gabriel Nuñez, David E Smith
There is increasing evidence that proton-coupled oligopeptide transporters (POTs) can transport bacterially derived chemotactic peptides and therefore reside at the critical interface of innate immune responses and regulation. However, there is substantial contention regarding how these bacterial peptides access the cytosol to exert their effects and which POTs are involved in facilitating this process. Thus, the current study proposed to determine the (sub)cellular expression and functional activity of POTs in macrophages derived from mouse bone marrow and to evaluate the effect of specific POT deletion on the production of inflammatory cytokines in wild-type, Pept2 knockout and Pht1 knockout mice...
May 21, 2018: Journal of Immunology: Official Journal of the American Association of Immunologists
Shenghong Yang, Xiao Chen, Shuqin Liu, Fuxin Wang, Gangfeng Ouyang
Fluorescent carbon nanoparticles (FCNPs) have been deeply researched and widely applied in recent years due to their good optics performance, chemical stability and biocompatibility. Herein, a green and rapid microwave-assisted solid-phase synthesis (solvent-free) approach was proposed for the fabrication of highly FCNPs in a very short period of time, 4 min. The as-prepared FCNPs can emit a blue emission with quantum yield of up to 63.2% in water solution and show yellow fluorescence in the solid state. The FCNPs also exhibit special solvent effect that the fluorescence emission can be adjusted by controlling the solvent ratio of ethanol and water...
August 15, 2018: Talanta
Xiang Han, Chang Tian, Jingjing Jiang, Mao-Sen Yuan, Shu-Wei Chen, Juan Xu, Tianbao Li, Jinyi Wang
Hypochlorous acid plays a very important role in living cells, because it can resist microorganism attack and has a lethal effect on pathogens. The unnormal generation of ClO- can cause tissue damage and corresponding diseases. Detection of ClO- is very necessary in biological systems. In this article, we respectively hybridized the two different water-soluble coumarin (7-hydroxycoumarin and 7-diethylaminocoumarin) fluorophores with a longer-wavelength emissive rhodamine fluorophore to construct an intergrant, and then isothiocyanate was modified with the intergrant to recognized ClO- ...
August 15, 2018: Talanta
Xiuxuan Zhang, Yan Zhou, Xiaofei Gu, Yu Cheng, Manxin Hong, Liqiang Yan, Fulong Ma, Zhengjian Qi
Cytochrome P450s have brought considerable attention to researchers for their significant correlations with metabolic behaviors of procarcinogenic chemicals. To better understand the roles of CYP1A in biological and physiological systems, we developed a novel ratiometric fluorescence probe N-((2-hydroxyl ethoxy) ethyl)- 4-methoxy-1, 8-naphthalimide (NEMN) allowing for selectively and sensitively monitoring the target enzymes under physiological conditions and living cells. The probe was designed based on substrate predilection of CYP1A and its outstanding O-dealkylation capacity, and 1, 8-naphthalimide was chosen as fluorophore on account of its desirable photophysical properties...
August 15, 2018: Talanta
Chuanli Wu, Xiaoyan Liu, Yiyi Zheng, Wenjing He, Guancao Yang, Ping Wu, Chenxin Cai
This work reports an approach for imaging the localization, distribution, and level of miRNA in different organelles based on an activated fluorescence signal triggered by an alteration of the specific binding-induced conformation of the designed activatable probe. We selected miR-150 as an miRNA example to image its localization, distribution, and level in human cervical cancer cells (HeLa cells). The results indicate that miR-150 is localized and distributed in different subcellular organelles (mainly in mitochondria and lysosomes) and that its levels (actually its concentrations) in lysosomes are higher than those in mitochondria in both HeLa and MCF-7 cells...
August 15, 2018: Talanta
Qingqing Wu, Mao Mao, Wenlang Liang, Florian J Stadler
Development of thiol-specific fluorescent probes with selectivity in different thiol compounds is more practical and significant than those without that capacity. In this work, a new quinoline-derived fluorophore, hydroxyl-substituted quinoline-benzo[d]oxazole 6 with high fluorescence quantum yield is synthesized and esterified with acrylic acid to afford two fluorescent probes, BQA-1 and BQA-2 for selectively discriminating Cys from Hcys/GSH based on conjugate addition-cyclization mechanism. BQA-1 exhibits a large ratiometric fluorescence response toward Cys in aqueous pH 7...
August 15, 2018: Talanta
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