Solar and Storage Degradations of Oil- and Water-Soluble Fluorescent Dyes

2011 ◽  
Vol 27 (2) ◽  
pp. 211-216 ◽  
Author(s):  
L. R. Khot ◽  
M. Salyani ◽  
R. D. Sweeb
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sam Wong ◽  
Simone Alidori ◽  
Barbara P. Mello ◽  
Bryan Aristega Almeida ◽  
David Ulmert ◽  
...  

AbstractCellulose nanocrystals (CNC) are linear organic nanomaterials derived from an abundant naturally occurring biopolymer resource. Strategic modification of the primary and secondary hydroxyl groups on the CNC introduces amine and iodine group substitution, respectively. The amine groups (0.285 mmol of amine per gram of functionalized CNC (fCNC)) are further reacted with radiometal loaded-chelates or fluorescent dyes as tracers to evaluate the pharmacokinetic profile of the fCNC in vivo. In this way, these nanoscale macromolecules can be covalently functionalized and yield water-soluble and biocompatible fibrillar nanoplatforms for gene, drug and radionuclide delivery in vivo. Transmission electron microscopy of fCNC reveals a length of 162.4 ± 16.3 nm, diameter of 11.2 ± 1.52 nm and aspect ratio of 16.4 ± 1.94 per particle (mean ± SEM) and is confirmed using atomic force microscopy. Size exclusion chromatography of macromolecular fCNC describes a fibrillar molecular behavior as evidenced by retention times typical of late eluting small molecules and functionalized carbon nanotubes. In vivo, greater than 50% of intravenously injected radiolabeled fCNC is excreted in the urine within 1 h post administration and is consistent with the pharmacological profile observed for other rigid, high aspect ratio macromolecules. Tissue distribution of fCNC shows accumulation in kidneys, liver, and spleen (14.6 ± 6.0; 6.1 ± 2.6; and 7.7 ± 1.4% of the injected activity per gram of tissue, respectively) at 72 h post-administration. Confocal fluorescence microscopy reveals cell-specific accumulation in these target tissue sinks. In summary, our findings suggest that functionalized nanocellulose can be used as a potential drug delivery platform for the kidneys.


2015 ◽  
Vol 112 (8) ◽  
pp. E826-E835 ◽  
Author(s):  
Ian C. Shieh ◽  
Joseph A. Zasadzinski

Contrast in confocal microscopy of phase-separated monolayers at the air–water interface can be generated by the selective adsorption of water-soluble fluorescent dyes to disordered monolayer phases. Optical sectioning minimizes the fluorescence signal from the subphase, whereas convolution of the measured point spread function with a simple box model of the interface provides quantitative assessment of the excess dye concentration associated with the monolayer. Coexisting liquid-expanded, liquid-condensed, and gas phases could be visualized due to differential dye adsorption in the liquid-expanded and gas phases. Dye preferentially adsorbed to the liquid-disordered phase during immiscible liquid–liquid phase coexistence, and the contrast persisted through the critical point as shown by characteristic circle-to-stripe shape transitions. The measured dye concentration in the disordered phase depended on the phase composition and surface pressure, and the dye was expelled from the film at the end of coexistence. The excess concentration of a cationic dye within the double layer adjacent to an anionic phospholipid monolayer was quantified as a function of subphase ionic strength, and the changes in measured excess agreed with those predicted by the mean-field Gouy–Chapman equations. This provided a rapid and noninvasive optical method of measuring the fractional dissociation of lipid headgroups and the monolayer surface potential.


2010 ◽  
Author(s):  
Lav R Khot ◽  
Masoud Salyani ◽  
Roy D Sweeb

2018 ◽  
Vol 13 (12) ◽  
pp. 1616-1624 ◽  
Author(s):  
Chenguang Wang ◽  
Aiko Fukazawa ◽  
Yoshiyuki Tanabe ◽  
Naoto Inai ◽  
Daisuke Yokogawa ◽  
...  

2000 ◽  
Vol 113 (21) ◽  
pp. 3805-3814 ◽  
Author(s):  
J. Xu ◽  
D. Ziemnicka ◽  
G.S. Merz ◽  
L. Kotula

Macropinocytosis is an endocytic process that occurs through non-clathrin coated vesicles larger than 0.2 microm in diameter. Although macropinocytic vesicles are readily visualized in cultured cells by the introduction of fluorescent, water-soluble dyes into the culture medium, protein markers associated with this type of vesicles have not yet been well defined. Here, we report that human spectrin SH3 domain binding protein 1, or Hssh3bp1, associates with macropinosomes in NIH 3T3 fibroblasts. Hssh3bp1 macropinosomes are heterogeneous in morphology and size, do not endocytose transferrin and are resistant to brefeldin A treatment. Cytochalasin D, and wortmannin block endocytosis of fluorescent dyes into the Hssh3bp1 macropinosomes and dramatically affect their morphology. Overexpression of Hssh3bp1-green fluorescent protein abolished fusion of vesicles resulting in a decreased endocytosis of fluorescence dyes, thus suggesting a potential regulatory role of Hssh3bp1 in macropinocytosis. In the macropinosomes of NIH 3T3 cells, Hssh3bp1 associates with a 200-kDa protein that crossreacts with a monoclonal antibody to the erythroid alpha-spectrin SH3 domain. Thus macropinosomes in cells may contain a spectrin-like protein.


Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2923
Author(s):  
Piaopiao Chen ◽  
Iqra Ilyas ◽  
Su He ◽  
Yichen Xing ◽  
Zhigang Jin ◽  
...  

Polymer dots (Pdots) represent newly developed semiconductor polymer nanoparticles and exhibit excellent characteristics as fluorescent probes. To improve the sensitivity and biocompatibility of Pdots ratiometric pH biosensors, we synthesized 3 types of water-soluble Pdots: Pdots-PF, Pdots-PP, and Pdots-PPF by different combinations of fluorescent dyes poly(9,9-dioctylfluorenyl-2,7-diyl) (PFO), poly[(9,9-dioctyl-fluorenyl-2,7-diyl)-co-(1,4-benzo-{2,1′,3}-thiadazole)] (PFBT), and fluorescein isothiocyanate (FITC). We found that Pdots-PPF exhibits optimal performance on pH sensing. PFO and FITC in Pdots-PPF produce pH-insensitive (λ = 439 nm) and pH-sensitive (λ = 517 nm) fluorescence respectively upon a single excitation at 380 nm wavelength, which enables Pdots-PPF ratiometric pH sensing ability. Förster resonance energy transfer (FRET) together with the use of PFBT amplify the FITC signal, which enables Pdots-PPF robust sensitivity to pH. The emission intensity ratio (I517/I439) of Pdots-PPF changes linearly as a function of pH within the range of pH 3.0 to 8.0. Pdots-PPF also possesses desirable reversibility and stability in pH measurement. More importantly, Pdots-PPF was successfully used for cell imaging in Hela cells, exhibiting effective cellular uptake and low cytotoxicity. Our study suggests the promising potential of Pdots-PPF as an in vivo biomarker.


Author(s):  
J R Weddell

Studies with beef cattle (Kennedy and Carson, 1991) and dairy cattle (Chamberlain et al, 1990) have shown responses in dry matter intake of silage and animal performance through applying Maxgrass silage additive to unwilted herbage ensiled in clamps. Maxgrass (BP Chemicals Ltd) contains (weight/volume) 68% ammonium hexamethanoate, 11% ammonium hexapropanoate and 2% octanoic acid.Research at Aberdeen has shown the benefits of using both inoculant (Weddell, 1990a) and formic acid based (Weddell, 1990b) additives on big bale silage which now constitutes around 15% of the total silage dry matter ensiled in the UK. The present study compared the effects on silage composition, animal performance and storage losses of Maxgrass treated with untreated big bale silage.Second cut perennial ryegrass herbage was wilted to a mean DM content of 230 g/kg then baled by fixed chamber baler. Mean water soluble carbohydrate was 100 g/kg DM. Alternate groups of six bales were left untreated or treated with Maxgrass silage additive at 7.4 1/tonne wilted grass.


1980 ◽  
Vol 58 (10) ◽  
pp. 1851-1860 ◽  
Author(s):  
J. E. Phillips ◽  
W. Mordue ◽  
J. Meredith ◽  
J. Spring

Corpora cardiaca (CC), cAMP, and hemolymph all increase short-circuit current (Isc) and electropotential difference (PD) across locust rectum by stimulating electrogenic transport of Cl− from the lumen. Using ΔIsc as a bioassay, we have purified the water-soluble stimulant (CTSH) from CC using gel filtration chromatography, DEAE-Sephadex anion exchange, cellulose acetate electrophoresis, and thin-layer chromatography. A single peak of CTSH activity was observed after all these procedures, although small amounts of CTSH activity occasionally remained in the high molecular weight (MW) protein precipitate. CTSH was purified more than 100-fold on Bio-Gel P-30 columns. It has a MW of 8 000 – 12 000, is destroyed by trypsin digestion, and has a net negative charge over the pH range (5–10) at which it is most stable. Various properties (i.e., stability at 20 °C, localization in CC, MW, Rf values) and reciprocal bioassay s indicate that CTSH is different from diuretic, antidiuretic, and adipokinetic hormones from locust CC. No difference in the properties of CTSH from glandular (GL) and storage lobes (SL) of CC were noted, although 80% of activity was in the SL. The concentration of purified CTSH required to cause maximal stimulation of rectal Isc is less than 7 nM.


2013 ◽  
Vol 781-784 ◽  
pp. 431-435 ◽  
Author(s):  
Yue Jun Zhu ◽  
Jian Zhang ◽  
Bo Jing ◽  
Ye Bang Tan

The effect of ageing time on the macromolecular composition and conformation on intermolecular entanglement and crosslinking was investigated for a water-soluble, hydrophobically associating polymer (WSHAP), by steady-flow and oscillatory experiments at reservoir temperature (65 °C). The measurement of rheological properties was carried out with changing sample properties such as shear stress, shear rate and storage time. Moreover, for the investigated samples, the mathematical interpretation of relationship between the modulusGand the shear rate γ according to the Ostwald de Waele (power law) model, was carried out. Energy of viscous flow (Ea) has also been determined and discussed.


Sign in / Sign up

Export Citation Format

Share Document