One of the reasons why ionic liquids have received growing interest from researchers is their environmentally interesting characteristics, such as their negligible vapour pressure and their good ...chemical and thermal properties. In particular, dicationic ionic liquids whose thermal and electrochemical stability is higher than that of monocationic ionic liquids have begun to gain attention during recent years. In this work, monocationic and dicationic ionic liquids were synthesized, characterized and tested for their toxicity, which was assessed using the luminescent bacterium Vibrio fischeri. The results revealed that the toxicity of the ionic liquids mainly depends on the head groups and linkage chain length of their cationic structure. Introduction of a new cationic head decreased the EC50 (concentration which leads to 50% reduction in bioluminescence of the bacteria) of the ionic liquids. The results present a promising picture of dicationic ionic liquids as alternatives with lower environmental impact than their monocationic counterparts and underline the significance of designing particular structures for ionic liquids.
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•Measurement of the toxicity on Vibrio fischeri of twenty-six ILs by Microtox® test.•Dicationic ILs have lower environmental impact than their monocationic counterparts.•IL ecotoxicity is mainly influenced by alkyl chain and presence of one or two cations.•The higher is Log Kow of the IL, the higher is its membrane accumulation and toxicity.
Curcumin, extracted from the rhizome of
, has been widely used in medicine for centuries due to its anti-inflammatory, anti-cancer, anti-oxidant and anti-microbial effects. However, its ...bioavailability during treatments is poor because of its low solubility in water, slow dissolution rate and rapid intestinal metabolism. For these reasons, improving the therapeutic efficiency of curcumin using nanocarriers (e.g., biopolymer nanoparticles) has been a research focus, to foster delivery of the curcumin inside cells due to their small size and large surface area. Silk fibroin from the
silkworm is a biopolymer characterized by its biocompatibility, biodegradability, amphiphilic chemistry, and excellent mechanical properties in various material formats. These features make silk fibroin nanoparticles useful vehicles for delivering therapeutic drugs, such as curcumin. Curcumin-loaded silk fibroin nanoparticles were synthesized using two procedures (physical adsorption and coprecipitation) more scalable than methods previously described using ionic liquids. The results showed that nanoparticle formulations were 155 to 170 nm in diameter with a zeta potential of approximately -45 mV. The curcumin-loaded silk fibroin nanoparticles obtained by both processing methods were cytotoxic to carcinogenic cells, while not decreasing viability of healthy cells. In the case of tumor cells, curcumin-loaded silk fibroin nanoparticles presented higher efficacy in cytotoxicity against neuroblastoma cells than hepatocarcinoma cells. In conclusion, curcumin-loaded silk fibroin nanoparticles constitute a biodegradable and biocompatible delivery system with the potential to treat tumors by local, long-term sustained drug delivery.
The density and refractive index of ionic liquids (ILs) + water binary mixtures were determined as a function of temperature (from 293.15 to 343.15 K) at atmospheric pressure over the whole ...composition range in which the mixtures were miscible. To carry out a systematic study, all of the ILs selected are imidazolium-based ILs with a different number of carbons in the alkyl chain of the cation and also different anions (tetrafluoroborate, triflate, and octylsulfate). Specifically, the studied ILs were 1-ethyl-3-methylimidazolium tetrafluoroborate emimBF4, 1-butyl-3-methylimidazolium tetrafluoroborate bmimBF4, 1-hexyl-3-methylimidazolium tetrafluoroborate hmimBF4, 1-methyl-3-octylimidazolium tetrafluoroborate omimBF4, 1-ethyl-3-methylimidazolium triflate emimTfO, 1-butyl-3-methylimidazolium triflate bmimTfO, and 1-butyl-3-methylimidazolium octylsulfate bmimOcSO4. The excess molar volumes and the deviation in the molar refraction of the binary mixtures were calculated for a better understanding of the interactions that take place between the components and were successfully correlated by the Redlich–Kister empirical correlations. The Bahe–Varela model, which has a more physical meaning, was also used to successfully correlate the excess molar volume values. Volumetric properties, such as apparent molar volumes, partial molar volumes, isobaric thermal expansion coefficients, partial molar volumes at infinite dilution and excess partial molar volumes at infinite dilution were also calculated in order to obtain information about the influence of composition and temperature on the thermodynamic behavior of the selected ILs and water in the mixture. The results are discussed in order to understand the formation of hydrogen bonds between components of the mixture and the possible packing effects that take place in the mixing process. The density and refractive index experimental data were correlated by the Lorentz–Lorenz, Wiener, Dale–Gladstone, and Eykman equations to determine the relationship between both parameters, and good agreement between the experimental and calculated refractive index values was obtained.
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•High pressure phase equilibria of CO2 + organic compound binary systems were measured.•The compounds were 2-pentanol, butyric acid, vinyl butyrate and 2-pentyl butyrate.•Phase ...equilibrium measurements were carried out at 313.153 K, 323.15 K, and 333.15 K.•The experimental apparatus used was validated with the (CO2 + acetone) binary system.•Experimental data were successfully correlated by thermodynamic models (PR and SRK).
High pressure phase equilibrium for four binary systems, (CO2 + 2-pentanol, CO2 + vinyl butyrate, CO2 + 2-pentyl butyrate and CO2 + butyric acid), were measured at three temperatures of (313.15, 323.15 and 333.15) K and pressures up to 11 MPa. These four organic compounds are those involved in the kinetic resolution of rac-2-pentanol and their phase equilibria play a significant role in the separation processes of the reaction compounds. Phase behaviour measurements were taken using a synthetic method in a variable volume high-pressure cell. It was checked that the solubility of CO2 in the four systems decreases with increases in temperature at a constant pressure and all systems present type-I phase behaviour within scope of this work. Modifications of Henry's Law and Peng-Robinson and Soave-Redlich-Kwong equations of state combined with the Quadratic mixing rule were used to correlate experimental equilibrium data to determine the phase behaviour of these systems.
Acute myeloid leukemia (AML) is the second most common form of leukemia and the most frequent cause of leukemia-related deaths in the United States. The incidence of AML increases with advancing age ...and the prognosis for patients with AML worsens substantially with increasing age. Many older patients are ineligible for intensive treatment and require other therapeutic approaches to optimize clinical outcome. To address this treatment gap, novel agents with varying mechanisms of action targeting different cellular processes are currently in development. Hypomethylating agents (azacitidine, decitabine, SGI-110), histone deacetylase inhibitors (vorinostat, pracinostat, panobinostat), FMS-like tyrosine kinase receptor-3 inhibitors (quizartinib, sorafenib, midostaurin, crenolanib), cytotoxic agents (clofarabine, sapacitabine, vosaroxin), cell cycle inhibitors (barasertib, volasertib, rigosertib) and monoclonal antibodies (gentuzumab ozogamicin, lintuzumab-Ac225) represent some of these promising new treatments. This review provides an overview of novel agents that have either completed or are currently in ongoing phase III trials in patients with previously untreated AML for whom intensive treatment is not an option. Other potential drugs in earlier stages of development will also be addressed in this review.
This paper focuses on the use of ionic liquids (1-butyl-3-methylimidazolium methylsulphate, bmim+MeSO4−, and 1-ethyl-3-methylimidazolium acetate, emim+Ac−) to extract organic compounds involved in ...the racemic resolution of rac-2-pentanol (rac-2-pentanol, vinyl butyrate, rac-2-pentyl butyrate or butyric acid) from a mixture of one of these organic compounds with n-hexane. Liquid–liquid equilibrium data were experimentally obtained for seven ternary systems comprising an ionic liquid+rac-2-pentanol, vinyl butyrate, rac-2-pentyl butyrate or butyric acid+n-hexane at T=303.15K and atmospheric pressure. Binodal curves were measured applying the well-known procedure based on the observance of the cloud point while the compositions of the tie lines were calculated from refractive index and density measurements (the phase rich in the ionic liquid) and by gas cromatography (the phase rich in n-hexane). Selectivity values and the solute distribution ratio were utilized to test the possibility of the use of these ionic liquids as extractive solvents of the organic compounds implicated in the kinetic separation of the R- and S-enantiomers of rac-2-pentanol. The liquid-liquid equilibrium data of the ternary systems examined here have not previously been described in the literature.
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•LLE data of ternary systems involving ILs were determined at 303.15K and 0.1MPa.•bmim+MeSO4− and emim+Ac− can extract 2-pentanol and butyric acid from hexane.•Extraction efficiency is determined by the hydrophobicity of the compound and the IL.
Thermoplastic starch (TPS) films are considered one of the most promising alternatives for replacing synthetic polymers in the packaging field due to the starch biodegradability, low cost, and ...abundant availability. However, starch granule composition, expressed in terms of amylose content and phosphate monoesters, and molecular weight of starch clearly affects some film properties. In this contribution, biodegradable TPS films made from potato, corn, wheat, and rice starch were prepared using the casting technique. The effect of the grain structure of each starch on microstructure, transparency, hydration properties, crystallinity, and mechanical properties of the films, was evaluated. Potato starch films were the most transparent and corn starch films the most opaque. All the films had homogeneous internal structures-highly amorphous and with no pores, both of which point to a good starch gelatinization process. The maximum tensile strength (4.48-8.14 MPa), elongation at break (35.41-100.34%), and Young's modulus (116.42-294.98 MPa) of the TPS films were clearly influenced by the amylose content, molecular weight, and crystallinity of the film. In this respect, wheat and corn starch films, are the most resistant and least stretchable, while rice starch films are the most extensible but least resistant. These findings show that all the studied starches can be considered suitable for manufacturing resistant and flexible films with similar properties to those of synthetic low-density polyethylene (LDPE), by a simple and environmentally-friendly process.
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