scholarly journals Loading and Release of Charged and Neutral Fluorescent Dyes into and from Mesoporous Materials: A Key Role for Sensing Applications

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 249
Author(s):  
Estela Climent ◽  
Mandy Hecht ◽  
Knut Rurack
Keyword(s):  
Fluorescent Dyes ◽  
General Trend ◽  
Anionic Dyes ◽  
Sensing Applications ◽  
Sulforhodamine B ◽  
Silica Supports ◽  
Boron Dipyrromethene ◽  
Rhodamine 101 ◽  
Phosphate Buffered Saline ◽  
Fluorescein Dyes

The aim of this study is to determine the efficiency of loading and release of several zwitterionic, neutral, anionic and cationic dyes into/from mesoporous nanoparticles to find the optimum loading and release conditions for their application in detection protocols. The loading is carried out for MCM-41 type silica supports suspended in phosphate-buffered saline (PBS) buffer (pH 7.4) or in acetonitrile, involving the dyes (rhodamine B chloride, rhodamine 101 chloride, rhodamine 101 perchlorate, rhodamine 101 inner salt, meso-(4-hydroxyphenyl)-boron–dipyrromethene (BODIPY), sulforhodamine B sodium salt and fluorescein 27). As a general trend, rhodamine-based dyes are loaded with higher efficiency, when compared with BODIPY and fluorescein dyes. Between the rhodamine-based dyes, their charge and the solvent in which the loading process is carried out play important roles for the amount of cargo that can be loaded into the materials. The delivery experiments carried out in PBS buffer at pH 7.4 reveal for all the materials that anionic dyes are more efficiently released compared to their neutral or cationic counterparts. The overall best performance is achieved with the negatively charged sulforhodamine B dye in acetonitrile. This material also shows a high delivery degree in PBS buffer.

scholarly journals Permeability of homotypic and heterotypic gap junction channels formed of cardiac connexins mCx30.2, Cx40, Cx43, and Cx45

2007 ◽  
Vol 293 (3) ◽  
pp. H1729-H1736 ◽  
Author(s):  
Mindaugas Rackauskas ◽  
Vytas K. Verselis ◽  
Feliksas F. Bukauskas
Keyword(s):  
Molecular Mass ◽  
Gap Junction ◽  
Fluorescent Dyes ◽  
Single Channel ◽  
Lucifer Yellow ◽  
Cell Communication ◽  
Fluorescent Imaging ◽  
Anionic Dyes ◽  
Electrophysiological Recordings ◽  
Heterotypic Channels

We examined the permeabilities of homotypic and heterotypic gap junction (GJ) channels formed of rodent connexins (Cx) 30.2, 40, 43, and 45, which are expressed in the heart and other tissues, using fluorescent dyes differing in net charge and molecular mass. Combining fluorescent imaging and electrophysiological recordings in the same cell pairs, we evaluated the single-channel permeability ( Pγ). All homotypic channels were permeable to the anionic monovalent dye Alexa Fluor-350 (AF350), but mCx30.2 channels exhibited a significantly lower Pγ than the others. The anionic divalent dye Lucifer yellow (LY) remained permeant in Cx40, Cx43, and Cx45 channels, but transfer through mCx30.2 channels was not detected. Heterotypic channels generally exhibited Pγ values that were intermediate to the corresponding homotypic channels. Pγ values of mCx30.2/Cx40, mCx30.2/Cx43, or mCx30.2/Cx45 heterotypic channels for AF350 were similar and approximately twofold higher than Pγ values of mCx30.2 homotypic channels. Permeabilities for cationic dyes were assessed only qualitatively because of their binding to nucleic acids. All homotypic and heterotypic channel configurations were permeable to ethidium bromide and 4,6-diamidino-2-phenylindole. Permeability for propidium iodide was limited only for GJ channels that contain at least one mCx30.2 hemichannel. In summary, we have demonstrated that Cx40, Cx43, and Cx45 are permeant to all examined cationic and anionic dyes, whereas mCx30.2 demonstrates permeation restrictions for molecules with molecular mass over ∼400 Da. The ratio of single-channel conductance to permeability for AF350 was ∼40- to 170-fold higher for mCx30.2 than for Cx40, Cx43, and Cx45, suggesting that mCx30.2 GJs are notably more adapted to perform electrical rather than metabolic cell-cell communication.

scholarly journals EXTRAVASCULAR AND INTRATUBULAR DIFFUSION OF LABELED SERUM PROTEINS IN THE RAT TESTIS

1965 ◽  
Vol 13 (5) ◽  
pp. 376-385 ◽  
Author(s):  
R. E. MANCINI ◽  
O. VILAR ◽  
B. ALVAREZ ◽  
A. C. SEIGUER
Keyword(s):  
Fluorescent Dyes ◽  
Serum Proteins ◽  
Fluorescein Isothiocyanate ◽  
Seminiferous Tubules ◽  
Adult Rats ◽  
Ductus Deferens ◽  
Sulforhodamine B ◽  
Decline Curve ◽  
Immunofluorescent Technique ◽  
Germinal Cells

Rat whole serum, albumin, globulins, and fibrinogen were labeled with fluorescent dyes (sulforhodamine B. CI No. 45100 and fluorescein isothiocyanate); albumin was also tagged with radioactive iodine (I131) and tritium (H3). In addition heterologous albumin was also labeled with fluorescent dyes and radioiodine. The proteins were intravenously injected in prepubertal, pubertal and adult rats, and their decay in the circulation and histological distribution in the testis and epididymis was studied. As controls other animals were similarly injected with free labels alone and with labeled denatured and degraded albumin; also unlabeled homologous and heterologus albumins were administered followed by incubation of both organs with the corresponding labeled antisera applying the Coons' technique. It was observed: 1) with the exception of fibrinogen, labeled serum proteins rapidly appeared in the lumina of vessels, diffused extravascularly in the intertubular spaces and finally arrived inbetween the germinal cells and in the lumina of seminiferous tubules. Also labeled material was present in the lumen of epididymal canaliculi but not in the ductus deferens. 2) This extravascular and intratubular diffusion was parallel to the fast component of the time decline curve of labeled homologous serum proteins in the circulation. 3) There was no great difference between young and adult rats in the extravascular diffusion process, but intratubular passage was higher in pubertal and adult animals. 4) Control experiments revealed time presence of some fluorescent material only in the vessels and macrophages, whereas the immunofluorescent technique showed to very similar localization of unlabeled proteins to that provided by the injection of directly labeled proteins.

scholarly journals Recent Developments in Chitosan-Based Adsorbents for the Removal of Pollutants from Aqueous Environments

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 594
Author(s):  
Daniele C. da Silva Alves ◽  
Bronach Healy ◽  
Luiz A. de Almeida Pinto ◽  
Tito R. Sant’Anna Cadaval ◽  
Carmel B. Breslin
Keyword(s):  
Heavy Metal Ions ◽  
Organic Molecules ◽  
Anionic Dyes ◽  
Short Introduction ◽  
Silica Supports ◽  
Quality Of Water ◽  
Aqueous Environments ◽  
Recent Developments

The quality of water is continuously under threat as increasing concentrations of pollutants escape into the aquatic environment. However, these issues can be alleviated by adsorbing pollutants onto adsorbents. Chitosan and its composites are attracting considerable interest as environmentally acceptable adsorbents and have the potential to remove many of these contaminants. In this review the development of chitosan-based adsorbents is described and discussed. Following a short introduction to the extraction of chitin from seafood wastes, followed by its conversion to chitosan, the properties of chitosan are described. Then, the emerging chitosan/carbon-based materials, including magnetic chitosan and chitosan combined with graphene oxide, carbon nanotubes, biochar, and activated carbon and also chitosan-silica composites are introduced. The applications of these materials in the removal of various heavy metal ions, including Cr(VI), Pb(II), Cd(II), Cu(II), and different cationic and anionic dyes, phenol and other organic molecules, such as antibiotics, are reviewed, compared and discussed. Adsorption isotherms and adsorption kinetics are then highlighted and followed by details on the mechanisms of adsorption and the role of the chitosan and the carbon or silica supports. Based on the reviewed papers, it is clear, that while some challenges remain, chitosan-based materials are emerging as promising adsorbents.

scholarly journals A H2O2-Responsive Boron Dipyrromethene-Based Photosensitizer for Imaging-Guided Photodynamic Therapy

Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 32 ◽  
Author(s):  
Zhi-Wei Wang ◽  
Dan Su ◽  
Xiao-Qiang Li ◽  
Jing-Jing Cao ◽  
De-Chao Yang ◽  
...  
Keyword(s):  
Singlet Oxygen ◽  
Fluorescence Emission ◽  
Human Embryonic Lung ◽  
Buffer Solution ◽  
Promising Candidate ◽  
Oxygen Generation ◽  
Boron Dipyrromethene ◽  
Band Absorption ◽  
Phosphate Buffered Saline ◽  
Human Embryonic Lung Fibroblast

In this study, we demonstrate a novel H2O2 activatable photosensitizer (compound 7) which contains a diiodo distyryl boron dipyrromethene (BODIPY) core and an arylboronate group that quenches the excited state of the BODIPY dye by photoinduced electron transfer (PET). The BODIPY-based photosensitizer is highly soluble and remains nonaggregated in dimethyl sulfoxide (DMSO) as shown by the intense and sharp Q-band absorption (707 nm). As expected, compound 7 exhibits negligible fluorescence emission and singlet oxygen generation efficiency. However, upon interaction with H2O2, both the fluorescence emission and singlet oxygen production of the photosensitizer can be restored in phosphate buffered saline (PBS) solution and PBS buffer solution containing 20% DMSO as a result of the cleavage of the arylboronate group. Due to the higher concentration of H2O2 in cancer cells, compound 7 even with low concentration is particularly sensitive to human cervical carcinoma (HeLa) cells (IC50 = 0.95 μM) but hardly damage human embryonic lung fibroblast (HELF) cells. The results above suggest that this novel BODIPY derivative is a promising candidate for fluorescence imaging-guided photodynamic cancer therapy.

scholarly journals Hydrophobic analogues of rhodamine B and rhodamine 101: potent fluorescent probes of mitochondria in living C. elegans

2012 ◽  
Vol 8 ◽  
pp. 2156-2165 ◽  
Author(s):  
Laurie F Mottram ◽  
Safiyyah Forbes ◽  
Brian D Ackley ◽  
Blake R Peterson
Keyword(s):  
Fluorescent Probes ◽  
Rhodamine B ◽  
Laser Scanning ◽  
Fluorescent Dyes ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
C Elegans ◽  
Wide Range ◽  
Rhodamine 101

Mitochondria undergo dynamic fusion and fission events that affect the structure and function of these critical energy-producing cellular organelles. Defects in these dynamic processes have been implicated in a wide range of human diseases including ischemia, neurodegeneration, metabolic disease, and cancer. To provide new tools for imaging of mitochondria in vivo, we synthesized novel hydrophobic analogues of the red fluorescent dyes rhodamine B and rhodamine 101 that replace the carboxylate with a methyl group. Compared to the parent compounds, methyl analogues termed HRB and HR101 exhibit slightly red-shifted absorbance and emission spectra (5–9 nm), modest reductions in molar extinction coefficent and quantum yield, and enhanced partitioning into octanol compared with aqueous buffer of 10-fold or more. Comparison of living C. elegans (nematode roundworm) animals treated with the classic fluorescent mitochondrial stains rhodamine 123, rhodamine 6G, and rhodamine B, as well as the structurally related fluorophores rhodamine 101, and basic violet 11, revealed that HRB and HR101 are the most potent mitochondrial probes, enabling imaging of mitochondrial motility, fusion, and fission in the germline and other tissues by confocal laser scanning microscopy after treatment for 2 h at concentrations as low as 100 picomolar. Because transgenes are poorly expressed in the germline of these animals, these small molecules represent superior tools for labeling dynamic mitochondria in this tissue compared with the expression of mitochondria-targeted fluorescent proteins. The high bioavailabilty of these novel fluorescent probes may facilitate the identification of agents and factors that affect diverse aspects of mitochondrial biology in vivo.

scholarly journals Excited state dynamics of BODIPY-based acceptor–donor–acceptor systems: a combined experimental and computational study

2021 ◽  
Vol 23 (14) ◽  
pp. 8900-8907
Author(s):  
Zimu Wei ◽  
Sushil Sharma ◽  
Abbey M. Philip ◽  
Sanchita Sengupta ◽  
Ferdinand C. Grozema
Keyword(s):  
Excited State ◽  
Computational Study ◽  
Solvent Polarity ◽  
Excited State Dynamics ◽  
Sensing Applications ◽  
Boron Dipyrromethene ◽  
Donor Acceptor

Donor-bridge-acceptor systems based on boron dipyrromethene (BODIPY) are attractive candidates for bio-imagining and sensing applications because of their sensitivity to temperature, micro-viscosity and solvent polarity.

scholarly journals Recovery of nuclei from glycol-methacrylate-embedded tissue

Blood ◽  
1990 ◽  
Vol 76 (8) ◽  
pp. 1622-1625
Author(s):  
ET Wright ◽  
JW Jacobberger ◽  
TP Pretlow ◽  
TG Pretlow
Keyword(s):  
Organic Solvent ◽  
Fluorescent Dyes ◽  
Average Yield ◽  
Hoechst 33342 ◽  
Glycol Methacrylate ◽  
Background Staining ◽  
Enzymatic Markers ◽  
Sigma Chemical ◽  
Phosphate Buffered Saline

The analysis of antigens, enzyme histochemical markers, and DNA has become an important part of the classification of some leukemias, lymphomas, and other neoplastic diseases. Many of the relevant antigens and most of the relevant enzyme histochemical activities are destroyed and others are less than optimally preserved in tissues embedded in hot paraffin. Most enzymatic activities and antigens are well preserved in tissues embedded at 4 degrees C in glycol methacrylate (GMA). The measurement of DNA content in neoplastic cells with the most commonly employed techniques depended on the availability of fresh suspensions of cells until the development by Hedley of methods that permit the recovery of nuclei from paraffin blocks for this purpose. In order to facilitate the analysis of antigens, enzymatic markers, and DNA from the same sample of tissue, we have developed a means of recovery of nuclei from GMA-embedded tissues. Twenty-microns-thick sections of GMA- embedded tonsil were either pretreated with an organic solvent (absolute ethanol or 2-ethoxyethanol) followed by rehydration in phosphate buffered saline (PBS) or directly rehydrated in PBS. The suspensions were formed mechanically by gentle sonication. The type of fixative and length of PBS rehydration were varied. Tissue fixed in 100% acetone, embedded in GMA, and rehydrated directly in PBS for six days gave the highest average yield of nuclei, 3.7 x 10(7) nuclei per gram tissue. In order to assess DNA binding of fluorescent dyes, 2- microns-thick GMA sections were stained with chromomycin, Hoechst 33342 (Sigma Chemical, St Louis, MO), and propidium iodide. Hoechst 33342 bound specifically to the nuclei with low background staining.

scholarly journals Incorporation of a FRET dye pair into mesoporous materials: a comparison of fluorescence spectra, FRET activity and dye accessibility

The Analyst ◽  
2015 ◽  
Vol 140 (15) ◽  
pp. 5324-5334 ◽  
Author(s):  
Susanne Widmer ◽  
Michael J. Reber ◽  
Patrick Müller ◽  
Catherine E. Housecroft ◽  
Edwin C. Constable ◽  
...  
Keyword(s):  
Mesoporous Materials ◽  
Fluorescence Spectra ◽  
Fluorescent Dyes ◽  
Gas Sensing ◽  
Mesoporous Silicates ◽  
Sensing Applications ◽  
Particulate Systems

The incorporation of fluorescent dyes into mesoporous silicates was investigated as potential FRET based systems for gas sensing applications with better response than non-particulate systems.

Boronic Acid Functionalized Boron Dipyrromethene Fluorescent Probes: Preparation, Characterization, and Saccharides Sensing Applications

2012 ◽  
Vol 84 (23) ◽  
pp. 10214-10220 ◽  
Author(s):  
Jingying Zhai ◽  
Ting Pan ◽  
Jingwei Zhu ◽  
Yanmei Xu ◽  
Juan Chen ◽  
...  
Keyword(s):  
Fluorescent Probes ◽  
Boronic Acid ◽  
Sensing Applications ◽  
Boron Dipyrromethene

scholarly journals Delivery of Niacinamide to the Skin Using Microneedle-Like Particles

Pharmaceutics ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 326 ◽  
Author(s):  
Chong In Shin ◽  
MunSik Kim ◽  
Yeu-Chun Kim
Keyword(s):  
Fluorescent Dyes ◽  
Skin Surface ◽  
Skin Layer ◽  
Skin Permeability ◽  
Large Area ◽  
Sulforhodamine B ◽  
Chemical Peels ◽  
Model Drug ◽  
Fluorescein Sodium Salt ◽  
Permeability Enhancers

The stratum corneum is the outermost skin layer that obstructs the delivery of active ingredients found in cosmeceutical products. Chemical peels and microbeads have been used to overcome this layer, but these methods can cause side effects and are not environmentally friendly. While microneedles do not share the dangers mentioned above, they are currently only available as patches, which makes them unsuitable to be used with products that are usually applied onto a large area of the skin surface. Therefore, the aim of this study was to develop microneedle-like particles (MLP) whose needles would disrupt the skin during the rubbing process. A modified approach taken from conventional micromolding techniques was used to make the MLPs. The experimental results show that the fabricated structures had the required mechanical strength. Furthermore, after the application of the MLPs, the permeability of two fluorescent dyes, fluorescein sodium salt and sulforhodamine B increased to 217.6% ± 25.6% and 251.7% ± 12.8% respectively. Additionally, the permeability of a model drug, niacinamide, was shown to have increased to 193.8% ± 29.9%. Cryosectioned porcine slices also confirmed the ability of MLPs to enhance skin permeability by revealing a deeper penetration of the applied fluorescent dye. Altogether, the results demonstrate the potential of MLPs to be used as safe skin permeability enhancers that can be applied all over the skin.

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