1,721,154 research outputs found
pH-Dependent fluorescence of [La(OH)(2)](+)[ARS](-) hybrid nanoparticles for intracellular pH-sensing
Full text linkSaline inorganic–organic hybrid nanoparticles (IOH-NPs) [La(OH)2]+[ARS]− (ARS: alizarin red S) are prepared in water as a new compound (particle size: 47 ± 7 nm, ARS load: 65 wt%). The IOH-NPs not only show a pH-dependent absorption colour but also a pH-dependent fluorescence with green emission at pH 5.0–9.0 and red emission at pH < 4.5. According to first in vitro studies, the pH-dependend fluorescence can be used to monitor nanoparticle internalization in cells as well as the respective intracellular pH
Monitoring nanoparticle dissolution via fluorescence-colour shift
Full text link[La(OH)][ICG] and [La(OH)][PTC] inorganic–organic hybrid nanoparticles (IOH-NPs) with indocyanine green (ICG) and perylene-3,4,9,10-tetracarboxylate (PTC) as fluorescent dye anions are used for emission-based monitoring of the dissolution of nanoparticles. Whereas ICG shows a deep red emission in the solid [La(OH)][ICG] IOH-NPs, the emission of PTC in the solid [La(OH)][PTC] IOH-NPs is completely quenched due to π-stacking. After nanoparticle dissolution, the emission of freely dissolved ICG is weak, whereas freely dissolved PTC shows intense green emission. We report on the synthesis of IOH-NPs and nanoparticle characterization as well as on the fluorescence properties and how to avoid undesirable energy transfer between different fluorescent dyes. The emission shift from red (intact solid nanoparticles) to green (freely dissolved dye anions), indicating nanoparticle dissolution, is shown for aqueous systems and verified . Based on this first proof-of-the-concept, the IOH-NP marker system can be interesting to monitor nanoparticle dissolution in cells and tissues of small animals and to evaluate cell processes and/or drug-delivery strategies
High-load nanoparticles with a chemotherapeutic SN-38/FdUMP drug cocktail
Full text linkA cocktail of chemotherapeutic SN-38 and 5-FU/FdUMP in [Gd(OH)] 2+ [(SN-38) 0.5 (FdUMP) 0.5 ] 2− inorganic-organic hybrid nanoparticles shows promising efficacy on mouse pancreatic cancer cell lines.[Gd(OH)] 2+ [(SN-38) 0.5 (FdUMP) 0.5 ] 2− inorganic–organic hybrid nanoparticles (IOH-NPs) with a chemotherapeutic cocktail of ethyl-10-hydroxycamptothecin (SN-38, active form of irinotecan) and 5-fluoro-2′-deoxyuridine-5′-phosphate (FdUMP, active form of 5′-fluoruracil), 40 nm in size, are prepared in water. The IOH-NPs contain a total drug load of 63 wt% with 33 wt% of SN-38 and 30 wt% of FdUMP. Cell-based assays show efficient cellular uptake and promising anti-tumour activity on two pancreatic cancer cell lines of murine origin (KPC, Panc02). Beside the high-load drug cocktail, especially the option to use SN-38, which – although 100- to 1000-times more potent than irinotecan – is usually unsuitable for systemic administration due to poor solubility, low stability, and high toxicity upon non-selective delivery. The [Gd(OH)] 2+ [(SN-38) 0.5 (FdUMP) 0.5 ] 2− IOH-NPs are a new concept to deliver a drug cocktail with SN-38 and FdUMP directly to the tumour, shielded in a nanoparticle, to reduce side effects.A cocktail of chemotherapeutic SN-38 and 5-FU/FdUMP in [Gd(OH)] 2+ [(SN-38) 0.5 (FdUMP) 0.5 ] 2− inorganic-organic hybrid nanoparticles shows promising efficacy on mouse pancreatic cancer cell lines.[Gd(OH)] 2+ [(SN-38) 0.5 (FdUMP) 0.5 ] 2− inorganic–organic hybrid nanoparticles (IOH-NPs) with a chemotherapeutic cocktail of ethyl-10-hydroxycamptothecin (SN-38, active form of irinotecan) and 5-fluoro-2′-deoxyuridine-5′-phosphate (FdUMP, active form of 5′-fluoruracil), 40 nm in size, are prepared in water. The IOH-NPs contain a total drug load of 63 wt% with 33 wt% of SN-38 and 30 wt% of FdUMP. Cell-based assays show efficient cellular uptake and promising anti-tumour activity on two pancreatic cancer cell lines of murine origin (KPC, Panc02). Beside the high-load drug cocktail, especially the option to use SN-38, which – although 100- to 1000-times more potent than irinotecan – is usually unsuitable for systemic administration due to poor solubility, low stability, and high toxicity upon non-selective delivery. The [Gd(OH)] 2+ [(SN-38) 0.5 (FdUMP) 0.5 ] 2− IOH-NPs are a new concept to deliver a drug cocktail with SN-38 and FdUMP directly to the tumour, shielded in a nanoparticle, to reduce side effects.Deutsche Forschungsgemeinschaft https://doi.org/10.13039/50110000165
Monitoring Nanoparticle Interaction with Murine Breast Cancer Cells Using Multimodal Fluorescence Lifetime Microscopy
No full textTo investigate drug delivery in cancer therapy, we integrate fluorescence lifetime measurements, microspectrometry, and confocal laser scanning microscopy to track the uptake of inorganic–organic hybrid nanoparticles (IOH-NPs) by breast cancer cells over incubation periods ranging from 2 to 24 h. Non-radiative energy transfer (FRET) from the LysoTracker Green to the IOH-NPs confirms their lysosomal localization and possibly improves their optical excitation. Beyond the resolution limits of light and electron microscopy, fluorescence lifetime kinetics—including FRET—can thus reveal the nanoscale cellular localization of IOH-NPs and guide the optimization of fluorescence excitation. Here, we extend optical microscopy into a fifth dimension—picosecond fluorescence decay times—complementing 3D spatial and spectral information, establishing lifetime measurements as a versatile tool to study nanoparticle uptake in cancer therapy
Highly selective organ distribution and cellular uptake of inorganic-organic hybrid nanoparticles customized for the targeted delivery of glucocorticoids
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
3D correlative light and electron microscopy reveals the uptake and processing of inorganic-organic hybrid nanoparticles into cancer cells
Full text linkhttp://dx.doi.org/10.13039/100007569 Carl Zeiss Stiftunghttp://dx.doi.org/10.13039/100014989 Chan Zuckerberg Initiativ
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