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In this work, a microemulsion emitting fluorescence was fabricated as a potential oral delivery system for bioactive compounds. In simulated oral administration, the microemulsion was characterized for its microstructure by 1hydrogen-nuclear magnetic resonance (1H-NMR). Results showed that microemulsions not only have good resistance to oral and gastric phases, but also lay a solid foundation for the release of bioactive compounds in the intestine. Fluorescence stability tests showed that microemulsions exhibit a remarkable fluorescence intensity in the digestive environment, indicating feasibility as a label-free delivery carrier. Moreover, in vitro release tests of bioactive compounds confirmed that an α-linolenic acid (ALA)-loaded microemulsion mainly released in the intestine, thereby achieving the aim of controlling the release of bioactive compounds. These results suggest that the synthesized fluorescent microemulsion, combining the favorable features of nontoxicity, antidigestive stability, remarkable fluorescence intensity, and controllable release, can be regarded as a promising label-free delivery carrier for oral administration.

Five novel solvates of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) were crystallized and their crystal structures were elucidated. Solvate formation was found to be a multi-point molecular recognition and self-assembly process through C–H⋯O synthons. Hirshfeld surface analysis confirms that numerous C–H⋯O interactions are formed between the host and guest molecules, and the C–H⋯O contribution is greater for solvates than for polymorphs. Thermal analysis was performed to evaluate the thermal stability and verify the stoichiometry of solvates. The phase transformation during the desolvation process was in situ monitored by variable temperature powder X-ray diffraction. Both structural similarity and Ostwald's rule of stages play important roles in determining the polymorphs obtained after desolvation. These findings provide a promising route for multi-component crystal design of CL-20 using crystal engineering strategies.

In this work, the effects of α-linolenic acid (ALA) loaded in oil-in-water (O/W) and water-in-oil-in-water (W/O/W) microemulsions on cell viability, lactic dehydrogenase (LDH) viability, and reactive oxygen species (ROS) levels were examined using Cell Counting Kit-8 (CCK-8), an LDH assay kit, and a fluorescence microscope, respectively. The CCK-8 assay demonstrated that ALA inhibited MDA-MB-231 human breast cancer cell proliferation in a dose-dependent manner. Further, the results of LDH activity and ROS levels revealed that ALA-induced cancer cell damage was closely related to oxidative stress. Under the irradiation of ultraviolet light, the microemulsion without any added fluorescent dye would emit bright blue fluorescence, and the fluorescent images of the cells treated with ALA-loaded O/W and W/O/W microemulsions at different incubation times were taken, which exhibited long-term photostability and biocompatibility. In addition, the fluorescence mechanism of the microemulsion was explained by immobilizing surfactant molecules with aggregation-induced emission (AIE) properties at the water-oil interface through the microemulsion with a self-assembled structure. These findings showed the potential application of O/W and W/O/W microemulsions as the label-free delivery carriers in long-term imaging of living cells and real-time release monitoring of nutrients.

The crystallization and melting behaviors of binary tripalmitoylglycerol (PPP)/1,2-dioleoyl-3-palmitoyl glycerol (POO), tripalmitoylglycerol (PPP)/1,3-dipalmitoyl-2-oleoyl glycerol (POP), and 1,3-d...

Our previous work has demonstrated that α-linolenic acid (ALA)-loaded oil-in-water (O/W) microemulsion could enhance ALA antioxidant capacity. Meanwhile, we also observed that synthesized microemulsion itself had fluorescence. In this work, we have prepared a multiple water-in-oil-in-water (W/O/W) microemulsion to further enhance ALA antioxidant capacity and activate this delivery carrier application potential with a free label. The compositions of primary water-in-oil (W/O) microemulsion were obtained using pseudo-ternary phase diagrams, and then W/O/W microemulsion was prepared adopting the "two-step heterotherm method". The conductivity of W/O/W microemulsion was measured to lie between 250.0 and 350.0 μs/cm. The spherical droplets with a mean particle diameter of 10.0-20.0 nm were confirmed by transmission electron microscopy and dynamic light scattering. Nuclear magnetic resonance confirmed that ALA diffused to the multiple water-oily interface simultaneously. In addition, the in vitro release and antioxidant capacity measurements of ALA-loaded W/O/W microemulsion concluded the sustained-release effect and excellent antioxidant capacity. The fluorescent intensity of W/O/W microemulsion was markedly increased in comparison to O/W microemulsion. The synthesized microemulsion could lead to important applications and have advantages of a label-free fluorescent carrier for optical imaging purposes.

Various active ingredients play a crucial role in providing and supplementing the nutritional requirements of organisms. In this work, we attempted to chemically manipulate the interfacial microstructure of oil–water microemulsions (ME) with carbon dots (CDs), concentrating on substantially enhancing the antioxidant capacity of α-linolenic acid (ALA). To this end, CDs were synthesized and introduced into an ME. The molecular interaction of surfactant with CDs was investigated by Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The microstructure of the ME was monitored by transmission electron microscopy (TEM) and cryo-electron microscopy (cryo-EM). The cryo-EM result showed the oil–water interface in the ME was better defined after the CDs were loaded, and 1H NMR proved the CDs were distributed mainly at the interface. On the basis of these results, interfacial models were proposed. Final evaluation results demonstrated the stabilizing effect and oxidation-inhibition a...

Compared with traditional hot air drying method, the existence of optimal material layer thickness is a significant phenomenon in microwave thin layer drying process. In the current work, a new initial temperature-based methodology is proposed to predict the optimal thickness and to evaluate the effect of influential factors on optimal thickness. The evaluated optimal material layer thickness by the proposed methodology is consistent with experimentally measured value, and hence confirms that the optimal layer thickness can be predicted exactly through the average temperature of bulk material at the initial 1st min during pre-heating stage. With the help of the proposed methodology, it is discovered that attenuation factor, β, surface convective heat transfer coefficient, h, and environmental air temperature, T e are the main factors that affect the optimal thickness. And a larger β or T e tends to result in a smaller optimal thickness, while the situation for h is just the opposite. These results can play a crucial role in designing apt continuous microwave tunnel drying system or aid in guiding their operations.

Salt-dependent polymorphic control of glycine was investigated by using the microdroplet technique in this work. Sodium chloride (NaCl) was chosen as the additive to probe the influence of inorganic ions on the polymorphic nucleation of glycine. The thermodynamics and nucleation kinetics of glycine polymorphs in microdroplets were systematically analyzed based on the microdroplet technique. The crystal structures of the polymorphs were confirmed by powder X-ray diffraction (PXRD). The results illustrate that the critical concentration of NaCl required to induce the pure γ-form in the microdroplets is lower than that in the conventional method, which means that the microdroplet technique is more sensitive for the control of polymorph nucleation. The polymorphic nucleation selectivity of glycine was then discussed in view of classical nucleation theory. The results demonstrate that NaCl reduces the nucleation energy barrier of the γ-form of glycine, and for the same form of glycine, crystallization by the conventional method has a higher interfacial tension than in microdroplets.

Manipulating crystallization for macromolecule using ionic liquids (ILs) as an additive has received great attention, but how ILs accurately control their formation and crystallization pathway remains unclear. Here, we aim to illuminate the role of ILs on the solution chemistry of macromolecules by investigating their effects on the crystallization of lysozyme. The solubility findings show ILs changed intermolecular contacts, leading to lysozyme supramolecular repulsive interactions being induced or attractive interactions enhanced. Lysozyme was crystallized in the form of tetragonal crystals in the presence of [C4mim]BF4 (1-butyl-3-methylimidazolium tetrafluoroborate), [C4mim]Cl (1-butyl-3-methylimidazolium chloride) and [C4mim]Br (1-butyl-3-methylimidazolium bromide), while it was crystallized in the form of monoclinic crystals in the presence of [dmim]I (1,3-dimethylimidazolium iodine). Compared with that in the absence of ILs, lysozyme in the presence of [C4mim]Cl and [dmim]I contained a decreased α-helix content, but increased β-sheet content. The presence of [dmim]I also caused the β-turn content to increase and random coil content to decrease. This demonstration shows the formation of crystal nucleus is involved in transition at the protein secondary structure level, which may contribute to a better understanding of the role of ILs in the crystallization of bio-macromolecular materials and to developing a strategy to produce new bio-macromolecular materials using ILs.

The fractionation of oils has received considerable research attention, aiming at the modification of the properties of oils. The thermal and crystallization properties of palm kernel oil (PKO) and...

In this work, a one-step and two-phase solvothermal approach has been employed to synthesize Pt@C–O composite spheres formed by platinum (Pt) nanoparticles (NPs) anchored on oxygen-functionalized carbon spheres. The introduction of platinum(II) 2,4-pentanedionate (Pt(acac)2), benzoic acid, and chloromethane–glycerol two-phase solution is found to be significant for the formation of Pt@C–O composite nanostructures. Furthermore, the as-obtained Pt@C–O composites are found to have much more oxidized species of carbon (C–O) and platinum (Pt–O), as compared to commercial Pt/C. Results show that the Pt@C–O (CHCl3) catalyst based on the obtained Pt@C–O in a chloroform–glycerol mixture exhibits optimal electrocatalytic activity and superior carbon monoxide (CO) tolerance, which is mainly because the oxidation states of carbon and platinum cause the catalyst to regenerate during the methanol oxidation and CO anti-poisoning processes.

In this work, the effects of curcumin on the viability, morphology, and nanomechanics of SH-SY5Y neuronal cells were investigated using a conventional cell viability test kit (CCK-8) and sophisticated AFM imaging and force measurement techniques. CCK-8 tests show that SH-SY5Y neuronal cells have a dose-response to curcumin in terms of viability that is dependent on the exposure durations. When exposed to a maximum dosage of 32 μg/mL used in the present study for 4 h, 24 h, and 48 h, the cell viability dropped to 73.4 ± 4.5%, 9.1 ± 3.2%, and 2.5 ± 1.2% of the control, correspondingly. AFM studies show that curcumin can induce the disappearance of synapses of the cells and the change of biomechanics. After exposure for 24 h at the concentration of 16 μg/mL, the viscous deformation of the cells decreased from 2.15 ± 0.02 to 1.58 ± 0.03 (×10-15 N·m), the elastic deformation increased from 1.26 ± 0.04 to 1.72 ± 0.07 (×10-15 N·m), and adhesion work decreased from 0.56 ± 0.07 to 0.39 ± 0.04 (×10-16 N·m). The morphological and mechanical changes obtained using AFM can be interpreted from optically observed cellular structural changes. The present study provides insights into the effects of curcumin on neuronal cells from both biological and biophysical aspects, which can help more comprehensively understand the interactions between curcumin and SH-SY5Y cells. The demonstrated techniques can be potentially used to assess the efficacy of bioactive constituents on cells or help screen drugs.

For platinum (Pt) composite electrocatalysts formed by multiple components, the selective growth of Pt on oxygen-containing species can maximize the CO-resistance and durability, which is a big challenge in interfacial science. In this paper, Pt/TaON|N-rGO composite was obtained by an in-situ calcination of a layered supramolecule self-assembled by TaCl5, urea and n-butanol, followed with the targeted growth of Pt nanoparticles induced by the defects at the junction of TaON|N-rGO. As a result, Pt/TaON|N-rGO electrode with the ideal ternary interface of Pt|TaON|N-rGO exhibited exceptionally high catalytic mass activity (250.6 mA·mg−1Pt), excellent CO-tolerance (If/Ib = 1.6 normalized to Pt/C) and long-term durability (136.4 mA·mg−1Pt after continuous 1200 min operation) for EG oxidation in acid, compared to commercial Pt/C (57.8 mA·mg−1Pt). The promoted performance was attributed to the synergies at ternary interface of Pt|TaON|N-rGO, and the boosting CO-tolerance was achieved by the shortened L-H pathway ascribed to the selective growth of Pt nanoparticles on the heterojunction of TaON|N-rGO.

In this work, the solvent-mediated phase transformation of the metastable form (Form II) to the stable form (Form I) of ethenzamide–saccharin cocrystal in isopropanol was investigated. Solubility of Form I and Form II in pure isopropanol was also measured. The transformation mechanism from Form II to Form I was analyzed by some online and off-line tools including attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, Raman spectroscopy, and polarizing microscopy. The results demonstrate that the transformation process consists of three steps, involving the dissolution of Form II, the nucleation of Form I, and the following growth of Form I. The ATR-FTIR and Raman results show that the polymorphic transformation from Form II to Form I is controlled by the nucleation and growth of Form I. Furthermore, the microscope photographs clearly reveal that the Form I preferably nucleates and grows on the (100) surface of Form II. The molecular simulation results indicate that higher adsorpt...

Platinum nanocrystals with different growth rates along 〈100〉 to 〈111〉 are selectively shaped using the reaction solvent, which is due to the different reduction rates in diverse reaction solutions. Electrocatalytic results show that the branched and cubic Pt/C catalysts exhibit much higher ECSA and enhanced activity of MOR, in addition, the branched Pt/C catalyst shows improved durability.

Platinum (Pt) nanoassemblies with different morphologies, such as nanospheres self-assembled from nanoparticles, multipolyhedral nanostructures built with octahedral nanocrystals, hollow nanospheres consisting of armed nanoparticles, and two-dimensional arrays arranged by nanocubes, were synthesized by a solvothermal approach. The concentration gradient of Pt monomers plays a key role in the architecture of the self-assembled nanostructures, which is attributed to the weak dissolution of the Pt precursor in high-viscosity solvent. As a consequence, the electrode prepared from hollow Pt nanospheres consisting of armed nanoparticles shows much higher performance in the methanol electro-oxidation process than others. Meanwhile, the electrodes prepared from these novel Pt nanoassemblies exhibited long-term durability for methanol electro-oxidation, compared to the electrode prepared from monodispersed Pt nanoparticles.

Moxidectin is a single-component and semisynthetic macrocyclic lactone antibiotic, which has been widely used in the prevention and treatment of parasites in farm animals. In this paper, the transformation of ethanol solvate to form I of moxidectin in an ethanol–water mixture was studied. Offline methods and online instruments were used to monitor and identify the transformation process, and the influences of water content and temperature were discussed. It is noted that the transformation kinetics are highly sensitive to both the solvent composition and temperature and the transformation rate is a function of the ethanol content in aqueous ethanol mixtures. The solvent-mediated polymorphic transformation mechanism from ethanol solvate to form I was suggested, and the process is controlled by the nucleation and growth rate of the stable form. Understanding these effects can aid optimization and improve process control in the crystallization of moxidectin.

Protein crystallization is a complex physical and chemical process. The high-quality protein crystal is still a persistent bottleneck to the application of X-ray crystallography in structural biology. The additives may promote formation of crystal nucleus and subsequent growth in protein crystallization. As a distinct material, ionic liquids (ILs) have aroused great attention and interest for protein crystallization due to their unique properties. We reviewed the progress of protein crystallization and reported research about protein crystal morphology control by ILs, as crystal growth template, in aqueous solutions. ILs encourage changes in some cases in terms of growth morphology and crystal size. The effect of ILs on lysozyme growth morphology can be attributed to changing interaction among lysozyme molecules in aqueous solutions. This work can provide some initial insight into the preparation of high quality crystal and the development of new crystal form.

Understanding the salting effects on the solubility and transformation kinetics of amino acid solvates in aqueous solutions is important for a rational design of the industrial isolation and purification conditions of amino acid. We report measurements of l-phenylalanine anhydrate and monohydrate solubility as a function of temperature in aqueous NaCl, KCl, Na2SO4, and (NH4)2SO4 solutions with concentrations of 4 g/100 g of H2O in this work. It is found that salts play an important role in determining solubility reduction and solvated behavior, which had not been elucidated. This comparison has provided important insight into the dependence of l-phenylalanine solvates on temperature. The dependence of the l-phenylalanine anhydrate/monohydrate transformation kinetics on temperature in the presence of NaCl, as a typical salt, is discussed. It is noted that NaCl can markedly increase the rate of the transformation of l-phenylalanine between anhydrate and monohydrate compared with pure water. A simple model f...

The solubility of xylitol in ethanol+water solvent mixtures was measured at temperatures ranging from 278.00 K to 323.00 K at atmospheric pressure by using a laser technique. The results of these measurements were correlated by the combined nearly ideal binary solvent CNIBS/Redlich-Kister equation. The experimental solubility and correlation equation in this work can be used as essential data and models in the purification process of xylitol. The variant 2 in the CNIBS/R-K models was confirmed to be more adaptable to predict solubility of xylitol in binary ethanol +water system. Using the experimentally measured solubilities, the thermodynamic properties of dissolution of xylitol, such as Gibbs energy, molar enthalpy of dissolution, and molar entropy of dissolution, were calculated.

Research shows some potential applications for ionic liquids (ILs) with biomaterials. In this work, the ILs 1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim]BF4), 1-butyl-3-methylimidazolium chloride ([C4mim]Cl), 1-butyl-3-methylimidazolium bromide ([C4mim]Br), and 1,3-dimethylimidazolium iodine ([dmim]I) were employed to investigate their effects on the solubility of lysozyme in aqueous solutions at pH 4.5. The results demonstrate that lysozyme solubility increases with the addition concentration of [C4mim]BF4 and [C4mimCl] and is nearly invariable with the increase of the [C4mim]Br concentration. Interestingly, the solubility slowly decreases with the increase of [dmim]I concentration. At constant added IL concentration, the solubility increases with increasing temperature. The effect of ILs on solubility can be attributed to changing interaction among lysozyme molecules. The effect of ILs employed in this work may provide crucial insight into the preparation of high-quality crystals and the develo...

Ionic liquids (ILs) exhibit a variety of properties that make them attractive additives for biomaterials. 1-Butyl-3-methylimidazolium tetrafluoroborate ([C(4)mim]BF(4)), 1-butyl-3-methylimidazolium chloride ([C(4)mim]Cl), 1-butyl-3-methylimidazolium bromide ([C(4)mim]Br), and 1,3-dimethylimidazolium iodine([bmim]I), as additives during lysozyme crystallization, were tested for their effects on the thermal stability and morphology of lysozyme crystals obtained. [C(4)mim]Cl was chosen to evaluate the effect of IL addition concentration on the thermal stability of lysozyme. It is shown that the characteristic peak temperature and endothermic enthalpy values (DeltaH) for denaturation increase with increasing addition concentration. As for the degradation, peak temperatures decrease, whereas endothermic enthalpy values markedly increase with the rise of [C(4)mim]Cl addition concentration. In the case of adding [C(4)mim]BF(4), [C(4)mim]Br, and [bmim]I, similar thermal behaviors of lysozyme crystals were observed. The effect of ILs on thermal behaviors of lysozyme can be attributed to enhancing crystal contacts, changing conformational stability, or interaction among molecules, as evidenced by difference in crystal growth morphology. This study is especially helpful in controlling the thermal stability of lysozyme crystals and in gaining initial insight into potential crystallization conditions for prescreening ILs that stabilize the protein and other macromolecule crystals.

The thermal, phase transition and spectral studies of erythromycin A dihydrate and acetone solvate were performed by Differential Scanning calorimetry (DSC), Thermo Gravimetry (TG-DTA), X-Ray Powder Diffraction (XRPD) and Fourier Transform Infra-Red (FTIR) spectrum. The non-thermal kinetic analysis of erythromycin A dihydrate was carried out by DSC at different heating rates in dynamic nitrogen atmosphere. The result showed that heating rate has substantial influence on the thermal behavior of erythromycin dihydrate. The Arrhenius parameters were estimated according to the Kissinger method. Corresponding to dehydration of dihydrate, melting of dehydrated dihydrate, phase transition from dehydrated dihydrate to anhydrate, and melting of anhydrate, the calculated activation energy were 39.60, 269.85, 261.23, and 582.16 kJmol–1, the pre-exponential factors were 3.46 × 103, 8.06 × 1032, 9.23 × 1030, and 7.29 × 1063 s–1, respectively. Ozawa method was used to compare activation energy values calculated by Kissinger method. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The solubility of erythromycin A dihydrate in pure ethanol, propan-2-ol, methanol, acetone, chloroform, and acetone + water was measured by a synthetic method at temperature ranging from 293.20 K to 323.00 K at atmosphere pressure. The laser monitoring observation technique was used to determine the disappearance of the solid phase in a solid + liquid mixture. The results of these measurements were correlated by a semiempirical Apelblat equation.

The effect of five different impurities, the cations Al3+, Fe2+, and Mg2+ and the anions SO42- and Cl-, on the metastable zone width of phosphoric acid hemihydrate has been investigated using a laser method with a linear cooling rate. The metastable zone width was measured as a function of impurity concentration and cooling rate in the seeded system. The influences of impurity ions on the metastable zone width of phosphoric acid hemihydrate take place by different mechanisms. Mg2+ has enlargement effects on the metastable zone width, whereas Al3+ and Fe2+ have both enlargement or suppression effects under different impurity concentrations. Cl- and SO42- have relative weak effects on the metastable zone width.

The solubility of ammonium thiocyanate in different solvents (acetone, water, methanol, ethanol, ethanol + water mixtures) was measured by a synthetic method at different temperatures and at atmospheric pressure. The laser monitoring observation technique was used to determine the disappearance of the solid phase in a solid + liquid mixture. The results of these measurements were correlated with the modified Apelblat equation.

The solubility of acenaphthene in benzene, 1,3-dimethylbenzene, acetone, 1-propanol, and isobutanol was experimentally measured at temperatures ranging from (283.00 to 323.00) K. The laser monitoring observation technique was used to determine the disappearance of the solid phase in a solid + liquid mixture. The results of these measurements were correlated with the Apelblat equation.

Solubility of fluorene in benzene, chloroform, acetone, 1-propanol, isobutanol, and methylbenzene was experimentally measured at temperatures ranging from (283.00 to 323.00) K. The laser monitoring observation technique was used to determine the disappearance of the solid phase in a solid + liquid mixture. The results of these measurements were correlated with the Apelblat equation, which can be used as a useful model in the purification process of fluorene.