Polydiacetylene Liposomal Aequorin Bioluminescent Device for Detection of Hydrophobic Compounds

2016 ◽  
Vol 88 (11) ◽  
pp. 5704-5709 ◽  
Author(s):  
Ryoko Yamamoto ◽  
Shigehiko Takegami ◽  
Atsuko Konishi ◽  
Hikari Horikawa ◽  
Sayumi Yonezawa ◽  
...  
Keyword(s):  
Hydrophobic Compounds

Nanoemulsions Loaded with Amphotericin B: Development, Characterization and Leishmanicidal Activity

2019 ◽  
Vol 25 (14) ◽  
pp. 1616-1622 ◽  
Author(s):  
Gabriela Muniz Félix Araújo ◽  
Gabriela Muniz Félix Araújo ◽  
Alana Rafaela Albuquerque Barros ◽  
Alana Rafaela Albuquerque Barros ◽  
João Augusto Oshiro-Junior ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Average Diameter ◽  
Isopropyl Myristate ◽  
Neglected Diseases ◽  
Clinical Form ◽  
Hydrophobic Compounds ◽  
Internal Phase ◽  
Oil In Water ◽  
Spherical Structures ◽  
Lipid Formulations

Leishmaniasis is one of the most neglected diseases in the world. Its most severe clinical form, called visceral, if left untreated, can be fatal. Conventional therapy is based on the use of pentavalent antimonials and includes amphotericin B (AmB) as a second-choice drug. The micellar formulation of AmB, although effective, is associated with acute and chronic toxicity. Commercially-available lipid formulations emerged to overcome such drawbacks, but their high cost limits their widespread use. Drug delivery systems such as nanoemulsions (NE) have proven ability to solubilize hydrophobic compounds, improve absorption and bioavailability, increase efficacy and reduce toxicity of encapsulated drugs. NE become even more attractive because they are inexpensive and easy to prepare. The aim of this work was to incorporate AmB in NE prepared by sonicating a mixture of surfactants, Kolliphor® HS15 (KHS15) and Brij® 52, and an oil, isopropyl myristate. NE exhibited neutral pH, conductivity values consistent with oil in water systems, spherical structures with negative Zeta potential value, monomodal size distribution and average diameter of drug-containing droplets ranging from 33 to 132 nm. AmB did not modify the thermal behavior of the system, likely due to its dispersion in the internal phase. Statistically similar antileishmanial activity of AmB-loaded NE to that of AmB micellar formulation suggests further exploring them in terms of toxicity and effectiveness against amastigotes, with the aim of offering an alternative to treat visceral leishmaniasis.

Development of an ethanolic two-phase system (ETPS) based on polypropylene glycol 2000 + ethylene glycol + ethanol for separation of hydrophobic compounds

2021 ◽  
Author(s):  
Filipe Smith Buarque ◽  
Cleide Mara Faria Soares ◽  
Ranyere Lucena de Souza ◽  
Matheus Mendonça Pereira ◽  
Álvaro Silva Lima
Keyword(s):  
Ethylene Glycol ◽  
Phase System ◽  
Polypropylene Glycol ◽  
Two Phase ◽  
Hydrophobic Compounds ◽  
Ethanol Content ◽  
Coexisting Phases ◽  
Phase Water ◽  
High Ethanol

Two-phase water-free systems containing high ethanol content in the coexisting phases can selectively partition hydrophobic molecules from natural biomass.

scholarly journals Effect of Bile on the Cell Surface Permeability Barrier and Efflux System of Vibrio cholerae

2004 ◽  
Vol 186 (20) ◽  
pp. 6809-6814 ◽  
Author(s):  
Arpita Chatterjee ◽  
Sohini Chaudhuri ◽  
Gargi Saha ◽  
Satadeepa Gupta ◽  
Rukhsana Chowdhury
Keyword(s):  
Outer Membrane ◽  
Vibrio Cholerae ◽  
Efflux Pump ◽  
Permeability Barrier ◽  
Synergistic Activity ◽  
Efflux System ◽  
Gram Negative ◽  
Outer Leaflet ◽  
Hydrophobic Compounds ◽  
Energy Dependent

ABSTRACT Gram-negative bacteria are inherently impermeable to hydrophobic compounds, due to the synergistic activity of the permeability barrier imposed by the outer membrane and energy dependent efflux systems. The gram-negative, enteric pathogen Vibrio cholerae appears to be deficient in both these activities; the outer membrane is not an effective barrier to hydrophobic permeants, presumably due to the presence of exposed phospholipids on the outer leaflet of the outer membrane, and efflux systems are at best only partially active. When V. cholerae was grown in the presence of bile, entry of hydrophobic compounds into the cells was significantly reduced. No difference was detected in the extent of exposed phospholipids on the outer leaflet of the outer membrane between cells grown in the presence or absence of bile. However, in the presence of energy uncouplers, uptake of hydrophobic probes was comparable between cells grown in the presence or absence of bile, indicating that energy-dependent efflux processes may be involved in restricting the entry of hydrophobic permeants into bile grown cells. Indeed, an efflux system(s) is essential for survival of V. cholerae in the presence of bile. Expression of acrAB, encoding an RND family efflux pump, was significantly increased in V. cholerae cells grown in vitro in the presence of bile and also in cells grown in rabbit intestine.

scholarly journals Yeast Cells in Microencapsulation. General Features and Controlling Factors of the Encapsulation Process

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3123
Author(s):  
Giulia Coradello ◽  
Nicola Tirelli
Keyword(s):  
Cell Body ◽  
Low Cost ◽  
Controlling Factors ◽  
Yeast Cells ◽  
Chemical Characteristics ◽  
Hydrophobic Compounds ◽  
Pharmaceutical Applications ◽  
Physico Chemical ◽  
Encapsulation Process ◽  
Broad Overview

Besides their best-known uses in the food and fermentation industry, yeasts have also found application as microcapsules. In the encapsulation process, exogenous and most typically hydrophobic compounds diffuse and end up being passively entrapped in the cell body, and can be released upon application of appropriate stimuli. Yeast cells can be employed either living or dead, intact, permeabilized, or even emptied of all their original cytoplasmic contents. The main selling points of this set of encapsulation technologies, which to date has predominantly targeted food and—to a lesser extent—pharmaceutical applications, are the low cost, biodegradability and biocompatibility of the capsules, coupled to their sustainable origin (e.g., spent yeast from brewing). This review aims to provide a broad overview of the different kinds of yeast-based microcapsules and of the main physico-chemical characteristics that control the encapsulation process and its efficiency.

The role of tree stem proximity in the spatial variability of soil water repellency in a eucalypt plantation in coastal Portugal

Soil Research ◽  
2005 ◽  
Vol 43 (3) ◽  
pp. 251 ◽  
Author(s):  
J. J. Keizer ◽  
A. J. D. Ferreira ◽  
C. O. A. Coelho ◽  
S. H. Doerr ◽  
M. C. Malvar ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Repellency ◽  
Soil Water Repellency ◽  
Individual Measurement ◽  
Hydrophobic Compounds ◽  
Ethanol Droplet ◽  
Central Portugal ◽  
Living Organisms ◽  
Tree Stem

Certain organic compounds derived from living organisms or their decaying parts are generally accepted to induce soil water repellency. Water repellency may therefore be expected to increase with proximity to organisms releasing hydrophobic compounds. This hypothesis is tested here for Eucalyptus globulus trees, since eucalypt species are frequently associated with elevated repellency levels. In a young, first-rotation plantation on coastal dune sands in central Portugal, repeat measurements of water repellency using the ‘Molarity of an Ethanol Droplet’ (MED) test were carried out in situ between April 2001 and May 2002. On 25 dates, repellency was measured at initially 2 and later 3 distances on 2 sides of 8–11 randomly selected trees. On 15 occasions, additional repellency measurements were performed within small grids aside 3 of the selected trees. The postulated decrease in topsoil water repellency with increased distance from eucalypt tree stems was found to apply on several individual measurement dates, as well as, more unexpectedly since repellency usually is a transient phenomenon, for the study period as a whole. The results confirm the general association of eucalypt trees with water repellency, and indicate that tree stem proximity is an important but not sufficient factor to explain repellency distribution in topsoil.

scholarly journals The association of low-molecular-weight hydrophobic compounds with native casein micelles in bovine milk

2015 ◽  
Vol 98 (8) ◽  
pp. 5155-5163 ◽  
Author(s):  
M. Cheema ◽  
M.S. Mohan ◽  
S.R. Campagna ◽  
J.L. Jurat-Fuentes ◽  
F.M. Harte
Keyword(s):  
Molecular Weight ◽  
Bovine Milk ◽  
Low Molecular Weight ◽  
Casein Micelles ◽  
Hydrophobic Compounds

scholarly journals Test of Some Aspects of Modelling the Sorption of Hydrophobic Compounds in Soils

2002 ◽  
Vol 20 (3) ◽  
pp. 231-242 ◽  
Author(s):  
Bogusław Buszewski ◽  
Radosław Zbytniewski
Keyword(s):  
Goodness Of Fit ◽  
Podzolic Soil ◽  
Least Squares Method ◽  
Sorption Isotherms ◽  
Domain Model ◽  
Linear Transformations ◽  
Equilibrium Studies ◽  
Soil Matrix ◽  
Model Calculations ◽  
Hydrophobic Compounds

A study was carried out on the sorption of the herbicide linuron in podzolic soil (one of the typical soils of Poland), the sorption isotherms being obtained using batch equilibrium studies. Modelling sorption phenomena involving the interactions of chemicals and particularly herbicides is very difficult because of the strong heterogeneity of the soil matrix. The present work presents the results of applying the most common models, i.e. Freundlich and Linear, as well as the newer concept of the Dual Reactive Domain model. The data obtained were validated using various statistical and chemometric methods. The results suggest that applying the non-linear least-squares method to obtain isotherm parameters gave a much better description of the sorption phenomena than often obtained using linear transformations of the adsorption equations. The study also showed that appropriate weighting schemes should be included in any model calculations. To test the goodness-of-fit of the model to the experimental data both the correlation coefficient and the Residual Root Mean Square Error were obtained. The models were also compared using the Extra Sum of Squares Principle statistical test.

Bacterial cleanup: lateral diffusion of hydrophobic molecules through protein channel walls

2010 ◽  
Vol 1 (3-4) ◽  
pp. 263-270 ◽  
Author(s):  
Bert van den Berg
Keyword(s):  
Diffusion Mechanism ◽  
Lateral Diffusion ◽  
Biofuel Production ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Hydrophobic Compounds ◽  
Protein Channel ◽  
Biochemical Research ◽  
Established Role ◽  
Hydrophilic And Hydrophobic Compounds

AbstractThe outer membrane (OM) of Gram-negative bacteria forms a very efficient barrier against the permeation of both hydrophilic and hydrophobic compounds, owing to the presence of lipopolysaccharides on the outside of the cell. Although much is known about the OM passage of hydrophilic molecules, it is much less clear how hydrophobic molecules cross this barrier. Members of the FadL channel family, which are widespread in Gram-negative bacteria, are so far the only proteins with an established role in the uptake of hydrophobic molecules across the OM. Recent structural and biochemical research has shown that these channels operate according to a unique lateral diffusion mechanism, in which the substrate moves from the lumen of the barrel into the OM via an unusual opening in the wall of the barrel. Understanding how hydrophobic molecules cross the OM is not only of fundamental importance but could also have applications in the design of novel, hydrophobic drugs, biofuel production and the generation of more efficient bacterial biodegrader strains.

scholarly journals Extraction of Triterpenic Acids and Phytosterols from Apple Pomace with Supercritical Carbon Dioxide: Impact of Process Parameters, Modelling of Kinetics, and Scaling-Up Study

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2790 ◽  
Author(s):  
Łukasz Woźniak ◽  
Anna Szakiel ◽  
Cezary Pączkowski ◽  
Krystian Marszałek ◽  
Sylwia Skąpska ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Process Parameters ◽  
Binary Systems ◽  
Cell Model ◽  
Intact Cell ◽  
Selective Extraction ◽  
Apple Pomace ◽  
Extraction Curve ◽  
Hydrophobic Compounds ◽  
The Impact

Apple pomace, a byproduct of juice production, is a rich source of bioactive compounds and nutrients. Supercritical fluid extraction was proposed as a method for a fast and selective extraction of hydrophobic compounds with a pharmaceutical potential from this matrix. Chromatographic analysis showed that the pomace contained significant amounts of such substances, the most abundant of them were ursolic acid, oleanolic acid, and β-sitosterol. The solubility was chosen as a primary factor for a selection of the extraction conditions; the best results were acquired for a temperature of 80 °C and a pressure of 30 MPa. The equation proposed by Chrastil was applied for the description of the impact of the process parameters on the solubility of the analytes; the obtained values of coefficients of determination were satisfactory, despite the fact that the equation was developed for binary systems. The extraction curves obtained during the experiments were used for the description of the process kinetics using the Broken plus Intact Cell model. The impact of the temperature, pressure, and flow rate of carbon dioxide on the mass transfer phenomena was investigated. The data obtained allowed the prediction of the extraction curve for the process conducted on the larger scale.

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