Water-soluble Organic Solvent Research Articles

A novel strategy accomplished by cell wall annular thickening with polymer for improving the mechanical performances of plantation wood

Inspired by the multi-level physiological structure of wood cell wall, a bionic method accomplished by annular thickening of cell wall by polymer was proposed to improve the mechanical performances of plantation wood. The thickening mechanism and the contribution of annular thickening of cell wall to the mechanical performances of plantation wood was analyzed. Results indicated that wood cell wall could be annularly thickened by the modification system prepared with water-soluble vinyl monomers and organic solvent. The flexural, compressive and impact strengths of plantation wood were synchronously improved after the treatment. The modulus of rupture of the prepared wood with 22.4% weight percentage gain reached up to 95.7 MPa which was higher than the TB 17 requirement based on the Chinese National Standard (GB 50206). The thickening degree which could be controlled by adjusting modifier concentration was closely related to the mechanical performance of treated wood.

Catalytic condition optimization in the conversion of nootkatone from valencene byYarrowia lipolytica

Yarrowia lipolytica was a widespread and promising object in biotechnology, which was used to increase the biotransformation of valencene into nootkatone in shake flasks in this study. The main objective of this work is to determine the optimum combination of transformation conditions in shake flasks on the basis of single factor process optimization experiment. The results showed that Y. lipolytica was cultured in medium for 36 hr (exponential phase) and the amount of added Y. lipolytica was 5% (v/v). The concentration of substrate valencene was 920 mg·L−1, and the transformation time was 36 hr after adding substrates. Dimethyl sulfoxide, a water-soluble organic solvent, was used as a co-solvent with a concentration of 0.8% (v/v). The maximum production of nootkatone was 628.41 ± 18.60 mg·L−1 and the conversion rate was 68.30 ± 2.02% at cultivation conditions of 32°C, 150 rpm, and PH 5.30. The results showed that optimizing the catalytic conditions can significantly increase the yield of nootkatone by Y. lipolytica. Practical applications Recently, natural nootkatone is increasingly important due to its flavoring and physiological effects, but the amount of nootkatone in plants is low and cannot meet the demand. Also, there were few studies about microbial transformation of valencene by Yarrowia lipolytica under certain catalytic conditions. We demonstrated that optimizing the catalytic conditions can significantly increase the yield of nootkatone. Therefore, it provides a basis for the subsequent use of genetic engineering to transform Y. lipolytica to produce nootkatone.

Controlling the Internal Structures of Polymeric Microspheres via the Introduction of a Water-Soluble Organic Solvent.

Polymeric microspheres with different internal structures have been widely used because of their characteristics in the structures. This paper reports a method of controlling the internal structures of polymeric microspheres via the introduction of a water-soluble organic solvent to the continuous phase in the foam phase preparation of porous polymeric microspheres. The introduction of a water-soluble organic solvent enables the control of polymeric microspheres’ internal structures, from porous to hollow. Because a water-soluble organic solvent is introduced, the organic solvent may be diffused toward the interface because of the affinity between the organic solvent and the oil droplets, resulting an accumulation of organic solvent molecules at the interface to form an organic solvent layer. The presence of this layer may decrease the evaporation rate of the internal organic solvent in an oil droplet, which extends the time for the mingling of porogen droplets to form a few large pores or even an extremely large single pore inside. This method is also capable of altering the thickness of hollow microspheres’ shells in a desired way, with improved efficiency, yield and the capacity for continuous use on an industrial scale.

One-step lipid extraction for plasma lipidomics analysis by liquid chromatography mass spectrometry.

In the past decade, various lipidomics methodologies have been developed using mass spectrometry based analytical technologies, enabling wide coverage lipid detection in a quantitative manner. Hence, lipidomics has become a widely-accepted approach for biomarker discovery and mechanism elucidation in both medical and biology research fields; however, there are still technical challenges. In this study, focusing on the sample preparation procedure, a single step deproteinization by a water-soluble organic solvent, such as methanol (MeOH), ethanol (EtOH), isopropanol (IPA) or acetonitrile (ACN), was evaluated and proved to be satisfactory for lipidomics analysis. Moreover, during this investigation ACN deproteinization was revealed to not be an effective method for lipid extraction because lipid decomposition was observed during the protein precipitation process through lipase activation, potentially due to the insufficient protein denaturation. Therefore, excluding ACN, protein precipitation by alcohol was evaluated as the lipid extraction reagent. Moreover, adding the MTBE-MeOH (mMM) method, one of the major liquid-liquid extraction methods for shotgun lipidomics, these four approaches were compared. Lipids were extracted from mouse plasma by these four methods and used for exhaustive lipid profiling by liquid chromatography mass spectrometry (LC/MS) analysis. Comparison of these four methods revealed that alcohol based protein precipitation was a useful sample preparation procedure for LC/MS based lipidomics analysis. Whereas MeOH extraction was appropriate for hydrophilic lipid species, IPA was effective for hydrophobic lipids such as triacylglycerols (TG). In practice, EtOH extraction is thought to be the best approach to cover wide range of lipid species using a simple preparation procedure.

Fractionation of binary polymer blend based on size distribution of particles prepared by phase inversion method

A previous study demonstrated that relatively monodispersed particles of poly(styrene-co-acrylonitrile) (SAN) can be prepared through the phase inversion of water-in-oil (W/O) to oil-in-water (O/W) emulsions containing a water-soluble organic solvent as the oil phase. In this study, we apply the phase inversion method to binary polymer blend systems, i.e., SAN and polystyrene (PS), poly(styrene-co-butadiene) (PSB), or polycyclohexylmethacrylate (PCM). The size distributions of particles produced from the binary polymer blends of SAN + PS and SAN + PSB, but not of SAN + PCM, are carried out by adding the distributions of the original single polymers, where a single SAN system produces small particles (below 1 μm), while the main products of the single PS and PSB systems are large particles with broad size distributions. After small particles below 2 μm and large particles above 10 μm are collected by filtrating as-prepared particle dispersions, FT-IR analysis of the collected particles reveals that the small particles contain mainly SAN and the large particles are enriched with PS or PSB. Accordingly, we demonstrate that the phase inversion method fulfills a fractionation potential of binary polymer blends into the original components based on particle size difference.

Magnetic modification of diamagnetic agglomerate forming powder materials

A simple method for the magnetic modification of various types of powdered agglomerate forming diamagnetic materials was developed. Magnetic iron oxide particles were prepared from ferrous sulfate by microwave assisted synthesis. A suspension of the magnetic particles in water soluble organic solvent (methanol, ethanol, propanol, isopropyl alcohol, or acetone) was mixed with the material to be modified and then completely dried at elevated temperature. The magnetically modified materials were found to be stable in water suspension at least for 2 months.

Formation of monodisperse hierarchical lipid particles utilizing microfluidic droplets in a nonequilibrium state.

A new microfluidic process was used to generate unique micrometer-sized hierarchical lipid particles having spherical lipid-core and multilamellar-shell structures. The process includes three steps: (1) formation of monodisperse droplets in a nonequilibrium state at a microchannel confluence, using a phospholipid-containing water-soluble organic solvent as the dispersed phase and water as the continuous phase; (2) dissolution of the organic solvent of the droplet into the continuous phase and concentration of the lipid molecules; and (3) reconstitution of multilamellar lipid membranes and simultaneous formation of a lipid core. We demonstrated control of the lipid particle size by the process conditions and characterized the obtained particles by transmission electron microscopy and microbeam small-angle X-ray scattering analysis. In addition, we prepared various types of core-shell and core-core-shell particles incorporating hydrophobic/hydrophilic compounds, showing the applicability of the presented process to the production of drug-encapsulating lipid particles.

Microcrystals engineering using assemblies of di-protonated meso-tetraphenylporphine dimers under Zundel cations operation

New approach based on the usage of self-organized assemblies of di-protonated meso-tetraphenylporphine (TPP) dimers under Zundel cations action is suggested for the microcrystals engineering. Properties of the assemblies consisting of water and the protonated dimers, as produced in aqueous HCl in the presence of a small concentration of water-soluble organic solvent were investigated by UV–Vis and infrared spectroscopy and atomic force microscopy (AFM) in thin films. The self-organized assemblies consisting of water and di-protonated TPP dimers looked like long rods produced green crystals. These crystals were found by light microscopy. The ordered assembled structures crystallized into thin layers at open air at relative humidity of least 60%. Three acts of the microcrystals engineering actions are needed to obtain the green crystals that are (i) self-assembling of protonated TPP dimers under Zundel cations operation; (ii) generation of pure rod precursor in the di-protonated state and (iii) application of gaseous water to initiate the crystallization in order to Zundel cations action in the surface layer could occur. The size of the green crystals produced by the self-organized assemblies varies within 30–35μm.

One-step synthesis of spherical/nonspherical polymeric microparticles using non-equilibrium microfluidic droplets

A simple but versatile microfluidic process is presented for the production of monodisperse polymeric microparticles using non-equilibrium droplets. Oil-in-water (o/w) droplets were formed within microchannels by means of a water-soluble polar organic solvent containing polymer molecules as a dispersed phase. The droplets of solvent were rapidly dissolved into the continuous phase during flow through the microchannel, whereas water-insoluble polymers were precipitated to form monodisperse polymeric particles. In this way, we successfully synthesized particles with sizes significantly smaller than that of the initial droplets, using polystyrene and poly(methyl methacrylate) as the polymer molecules and typically ethyl acetate as the polar solvent. Particles obtained under several different conditions exhibited unique non-spherical morphologies, which were caused by the translocation and segregation of the precipitated polymer and diminishing solvent-rich droplet. We confirmed that various factors influence the particle morphology, including the polymer concentration, molecular weight of the polymer, type of the polar solvent, and the presence of additives in the dispersed phase.

Comparative study on diffusion and evaporation emulsion methods used to load hydrophilic drugs in poly(ortho ester) nanoparticle emulsions

Poly(ortho ester) (POE) nanoparticles were prepared by two different emulsification techniques: novel double emulsion solvent diffusion (DESD) and double emulsion solvent evaporation (DESE). We investigated the effect of sonication time/speed, type of organic phase solvents, polymer concentration, organic/aqueous phase ratio, surfactant type and concentration on the mean particle sizes of obtained POE nanoparticles by both DESD and DESE methods. Different organic solvents [ethyl acetate, methyl ethyl ketone, acetone, dichloromethane and chloroform] were used with several stabilizers [pluronic F 68, didodecyl dimethyl ammonium bromide, poly(vinyl alcohol), and sodium dodecyl sulfate]. The particle size of nanoparticles was observed by the dynamic light scattering method and transmission electron microscopy. We assumed that combining the double emulsion system with a partially water-soluble organic solvent, ethyl acetate, would result in better encapsulation efficiency of water-soluble drugs in nanoparticles and the utilization of both biocompatible surfactants and solvents. As a model drug, we used vancomycin hydrochloride, a hydrophilic low molecular weight glycopeptide antibiotic. The new nanoparticle preparation technique, DESD, resulted in improved formulation characteristics including smaller size, lower size distribution, higher encapsulation yield, and more biocompatible ingredients with unaltered bioactivity of vancomycin hydrochloride in comparison to classical DESE method used to load hydrophilic molecules.

Extraction and Preconcentration of Some Triazole Pesticides in Grape Juice by Salting Out Homogeneous Liquid–Liquid Extraction in a Narrow-Bore Tube Prior to Their Determination by Gas Chromatography–Flame Ionization Detection

A fast and simple extraction and preconcentration method for some triazole pesticides has been developed using a homogeneous liquid–liquid extraction method performed in a narrow-bore tube. The extraction is based on phase separation of a water-miscible organic solvent from aqueous solution in the presence of a salting out agent. In this work, the homogeneous solution of water and acetonitrile (water-soluble extraction solvent) was broken by addition of 30 %, w/v, sodium chloride (salting out agent). After sonication, a small volume of acetonitrile was collected on top of the tube and the extracted analytes in the collected phase were determined by gas chromatography–flame ionization detection. The effect of various experimental parameters including kind and volume of the water-soluble organic solvent, amount of salt, length and diameter of tube, and pH of sample solution was investigated. Under the optimum conditions, calibration graphs were linear over the range of 3–5,000 μg L−1. Relative standard deviations were less than 5.4 % for six repeated determinations (C = 100 μg L−1). Furthermore, the limits of detection (S/N = 3) and quantification (S/N = 10) were obtained in the ranges of 0.60–4.8 and 1.9–16 μg L−1, respectively. This method is very simple and rapid, requiring less than 10 min for sample preparation. It has been successfully utilized for the analysis of triazole pesticides in the grape juice samples.

Water-soluble organic solvent improves paraffin displacement in all-in-one epitope retrieval buffers

An all-in-one epitope retrieval buffer was developed to solubilize molten paraffin. This study illustrates that common all-in-one buffer additives such as surfactants and wetting agents do not solubilize molten paraffin but a water-soluble organic solvent (WSOS) does. This study also shows that the WSOS does not negatively impact immunohistochemical staining reactions. The addition of a WSOS into an all-in-one epitope retrieval buffer formulation maintains paraffin in solution when slides mounted with tissue sections are removed from the buffer. This action is an advantage for buffer tanks in which slides are in a vertical orientation; the slides are not recoated with molten paraffin.

Salting‐out homogeneous liquid–liquid extraction in narrow‐bore tube: Extraction and preconcentration of phthalate esters from water

In this study a simple and rapid sample preparation technique, homogeneous liquid-liquid extraction based on phase separation in the presence of a salt performed in a narrow-bore tube, followed by GC-flame ionization detection has been developed. In this work, sodium chloride and ACN were used as the salting-out agent and water-soluble extraction solvent, respectively. The homogeneous solution of water and ACN was broken by addition of the salt. Small volume of ACN was collected on top of the tube and the extracted analytes in the collected phase were determined. It has been successfully used for the analysis of five phthalate esters as model compounds in aqueous sample. Experimental parameters affecting the extraction efficiency such as kind and volume of the water-soluble organic solvent, length and diameter of the tube, and pH of the sample solution were investigated. Under the optimal conditions, the LODs were between 0.02 and 0.7 μg/L and enrichment factors were in the range of 172-309. In addition, good linearity (between 1 and 5000 μg/L) and high precision on the base of RSD (<8%, C = 600 μg/L, n = 6) were achieved.

Cyclosporin pro-dispersion liposphere formulation

ObjectivePreparation and characterization of an oral pro-dispersion liposphere formulation for cyclosporin, a water insoluble drug with limited bioavailability. MethodsPro-dispersion formulation consisted of a solid fat, dispersing agents and amphiphilic solvents as the major components besides cyclosporin A (CsA) were prepared in the present work. For preparation of this formulation, phospholipid was dissolved in pharmaceutically acceptable water soluble organic solvent, thereafter CsA along with other components was added and formulation optimization was carried out. After formulation preparation, particle size determination and in vitro release study was carried out. Additionally, ultracentrifugation, TEM, Cryo-TEM and DSC techniques were used for in vitro characterization of formulation. The prepared system was also compared with marketed Neoral® microemulsion formulation. ResultsLiposphere formulations were prepared and optimized as according to procedure. Though, determination of in vitro characteristics of such formulations is complex and difficult, yet selected and performed tests confirmed formation and existence of solid liposphere particles upon dispersion of formulation in water. It was also observed that particle size is influenced by the type of solid fat used and amphiphilic solvent present in the formulation. Prepared pro-dispersion was found to be stable for 2 years under normal storage conditions. ConclusionPrepared pro-dispersion liposphere formulation is a homogeneous solution of a lipophilic drug such as cyclosporin in a mixture of surfactants, lipids and ethyl lactate proved to spontaneously form dispersion when added to aqueous media. This formulation concept has a potential clinical use for improved bioavailability of water insoluble drugs.

A modified double-emulsion method for the preparation of daunorubicin-loaded polymeric nanoparticle with enhanced in vitro anti-tumor activity

The encapsulation of hydrophilic drug in polymeric nanoparticles with high loading remains a challenge due to the rapid penetration of the drug to the external aqueous phase. In order to improve the encapsulation efficiency of daunorubicin (DNR) in poly(d,l-lactic-co-glycolic acid (PLGA) and poly(d,l-lactic acid) (PDLLA) nanoparticles, we fabricated a series of DNR-loaded nanoparticles using a modified double-emulsion solvent evaporation/diffusion method, which introduced a partially water-soluble organic solvent into the particle formation. The influence of various preparation parameters was investigated systematically, such as the ratio of organic solvent, the type of surfactant, the type of polymers and the molecular weight. Results showed that regular spherical PLGA nanoparticles with diameters of 200–300 nm could be produced with a remarkably high DNR encapsulation efficiency (>80%) and loading (6.5% (w/w)). Upon encapsulation, the sustained release of DNR could be controlled over 2 weeks. The results of FT-IR and DSC analysis indicated that the encapsulated DNR in polymeric nanoparticles was inclusion, not absorption. Furthermore, optimized DNR/PLGA nanoparticles showed a significant enhancement of cellular uptake, higher cytotoxicity against HL-60 cells compared with free DNR. These results were potentially useful for the nanoparticle formulation of hydrophilic chemotherapeutic drugs that require efficient delivery to cancer cells as well as sustained release at the specific site.

A new double emulsion solvent diffusion technique for encapsulating hydrophilic molecules in PLGA nanoparticles

The commonly utilized techniques for encapsulating hydrophilic molecules in NP suffer from low encapsulation efficiency because of the drug rapid partitioning to the external aqueous phase. We hypothesized that combining the double emulsion system with a partially water-soluble organic solvent, could result in better encapsulation yield of hydrophilic molecules in nano-sized NP, and the utilization of both biocompatible surfactants and solvents. As a model drug we used alendronate, a hydrophilic low MW bisphosphonate. The new NP preparation technique, double emulsion solvent diffusion (DES-D), resulted in improved formulation characteristics including smaller size, lower size distribution, higher encapsulation yield, and more biocompatible ingredients in comparison to classical methods. The utilization of partially water-miscible organic solvent (ethyl acetate) enabled rapid diffusion through the aqueous phase forming smaller NP. In addition, the formulated alendronate NP exhibited profound inhibition of raw 264 macrophages, depletion of rabbit's circulating monocytes, and inhibition of restenosis in the rat model. It is concluded that the new technique is advantageous in terms of smaller size, lower size distribution, higher encapsulation yield, and more biocompatible ingredients, with unaltered bioactivity.

Enzymatic synthesis of conjugated linoleoyl ascorbate in acetone

Conjugated linoleoyl ascorbates were synthesized through the condensation of cis-9, trans-11-conjugated linoleic acid ( c9, t11CLA) or trans-10, cis-12-conjugated linoleic acid ( t10, c12CLA) with l-ascorbic acid (AsA) using immobilized lipase in a water-soluble organic solvent at 50 °C. The conversion was higher at higher polarity of the solvent and a higher ratio of CLA to AsA. The conversion for the synthesis of t10, c12CLA-AsA was higher than those for c9, t11CLA-AsA and linoleoyl ascorbate (LA-AsA), when Chirazyme ® L-2 C2 from Candida antarctica type B, which has been commonly used for enzymatic reaction in organic solvent, was used as a catalyst. The unmodified CLA isomers were almost completely oxidized within 4 h at 65 °C and 75% relative humidity, whereas all the CLA-AsAs were significantly resistant to oxidation. The oxidation kinetics was empirically expressed by the Weibull equation, and the rate constant, k, was estimated. The k values for CLA-AsAs and LA-AsA were about 1/30 and 1/60, respectively, of that for the corresponding unmodified CLA isomers. The enzymatic modification of CLA with AsA was an effective technique for improvement in the oxidative stability of CLA.

Rapid-set, waterborne coatings from polyzwitterionic polymers formulated with a critical solvent combination

Waterborne coatings that rapidly set and become tack-free can be prepared from polymers containing both pendant anionic (acidic, carboxylate, or strong-acid groups such as sulfonate) and cationic functionality (quaternary ammonium groups). This phenomenon is related to anion-cation interactions that function as ionic crosslinks and dramatically enhance the physical properties and water resistance of the coatings. We define this process as “controlled ionic-coacervation.” The best coating properties can only be obtained by using a “critical solvent combination.” The critical solvent combination requires water plus at least two organic solvents: (1) a lower boiling (70 to 134°C) water-soluble organic solvent having at least one hydroxyl group and (2) a higher boiling (135 to about 250°C) organic solvent. Loss of only a small amount of solvent causes a coating to rapidly become tack-free. Ionization of acid functionalities on the polymers by an increase in pH (e.g., through the loss of CO2) can initiate controlled ionic interactions. The influence of polymer and solvent compositions on coating properties is discussed.

Partitioning of some biomolecules at high pressures to aqueous/organic liquid–liquid phases of the carbon dioxide+water+1-propanol system

A completely miscible, binary liquid mixture of water and an organic solvent can reveal a liquid–liquid phase split, when it is pressurised with a ‘near-critical’ gas. The coexisting liquid phases in such a high-pressure three-phase equilibrium can be used to enable an extraction of biomolecules from an aqueous phase into a water-like organic phase. The basic design of such a process requires, at first, information on the behaviour of the phase forming ternary system of ‘near critical’ gas+water+water-soluble organic solvent, at second, experimental data on the partitioning of biomolecules to the coexisting phases and, at third, a method to correlate and predict such phase equilibrium. After a short introduction to the basic phase equilibrium phenomena, experimental results are reported for the partitioning of small amounts of six biomolecules — adenine, caffeine, methyl anthranilate, l-phenylalanine, salicyl alcohol and vanillin — on coexisting liquid phases in high-pressure three-phase vapour–liquid–liquid equilibrium of the ternary system ‘near critical’ carbon dioxide+water+1-propanol at 313 and 333 K. The experimental results for the partition coefficients are correlated with a semi-empirical approach, which combines an equation of state for describing the high-pressure multiphase equilibrium and the UNIQUAC excess Gibbs energy equation for describing the partitioning of the biomolecules.

New fluorescent cholesterol analogs as membrane probes

New fluorescent cholesterol analogs, (22 E,20 R)-3β-hydroxy-23-(9-anthryl)-24-norchola-5,22-diene ( R-AV-Ch), and the 20 S-isomer ( S-AV-Ch) were synthesized, their spectral and membrane properties were characterized. The probes bear a 9-anthrylvinyl (AV) group instead of C22–C27 segment of the cholesterol alkyl chain. Computer simulations show that both of the probes have bulkier tail regions than cholesterol and predict some perturbation in the packing of membranes, particularly for R-AV-Ch. In monolayer experiments, the force–area behavior of the probes was compared with that of cholesterol, pure and in mixtures with palmitoyloleoyl phosphatidylcholine (POPC) and N-stearoyl sphingomyelin (SSM). The results show that pure R-AV-Ch occupies 35–40% more cross-sectional area than cholesterol at surface pressures below film collapse (0–22 mN/m); whereas S-AV-Ch occupies nearly the same molecular area as cholesterol. Isotherms of POPC or SSM mixed with 0.1 mol fraction of either probe are similar to isotherms of the corresponding mixtures of POPC or SSM with cholesterol. The probes show typical AV absorption ( λ 386, 368, 350 and 256 nm) and fluorescence ( λ 412–435 nm) spectra. Steady-state anisotropies of R-AV-Ch and S-AV-Ch in isotropic medium or liquid–crystalline bilayers are higher than the values obtained for other AV probes reflecting hindered intramolecular mobility of the fluorophore and decreased overall rotational rate of the rigid cholesterol derivatives. This suggestion is confirmed by time-resolved fluorescence experiments which show also, in accordance with monolayer data, that S-AV-Ch is better accommodated in POPC–cholesterol bilayers than R-AV-Ch. Model and natural membranes can be labeled by either injecting the probes via a water-soluble organic solvent or by co-lyophilizing probe and phospholipid prior to vesicle production. Detergent-solubilization studies involving ‘raft’ lipids showed that S-AV-Ch almost identically mimicked the behavior of cholesterol and that of R-AV-Ch was only slightly inferior. Overall, the data suggest that the AV-labeled cholesterol analogs mimic cholesterol behavior in membrane systems and will be useful in related studies.