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关键词： Microwave heating   Synergy   Physicochemical properties  

摘要： Native starches are unsuitable for most industrial applications. Therefore, they are modified to improve their application in the industry. Starch may be modified using enzymatic, genetic, chemical, and physical methods. Due to the demand for safe foods by consumers, researchers are focusing on the use of cheap, safe and environmentally friendly methods such as the use of physical means for starch modification. Microwave heating of starch is a promising physical method for starch modification due to its advantages such as homogeneous operation throughout the whole sample volume, shorter processing time, greater penetration depth and better product quality. More recently, the use of synergistic methods for starch modification is being encouraged because they confer better functionality on starch than single methods. This review summarizes the present knowledge on the structure and physicochemical properties of starches from different botanical origins modified using microwave heating alone and in combination with other starch modification methods. (c) 2021 Elsevier B.V. All rights reserved.

关键词： Benzene bioisostere   MD   DFT   Bioavailability   Physicochemical properties  

摘要： Hyperlipidemia influences on numerous diseases, such as atherosclerosis, hypertension, and diabetes mellitus, however it still treatable. Atorvastatin is one of the most common statins;yet, it has poor solubility due to the three phenyl rings, which lead to low bioavailability issues. Herein, we used bicyclo [1.1.1] pentane a benzene bioisostere as a replacement for these phenyl groups. In total, seven analogous 1(a), 1(b), 1(c), 2(a), 2(b), 2(c), and 3 were designed and investigated theoretically. Their drug-likeness, physicochemical properties, bioactivity, and pharmacokinetics properties were reported and analyzed. Further DFT calculations at CAM-B3LYP/6-31+g in water were used to report the electronic properties and thermodynamic properties of the suggested analogues. Docking studied were conducted to mimic the interactions of the new derivatives with the active site of HMG-CoA reductase. Since docking results are not reliable, molecular dynamic simulations were carried out on analogous with the best docking score. Finally, binding free energy using MM-GBSA was calculated from the MD trajectories, reveals that compound 1(a) has promising properties as a drug with a docking score of -8.99 kcal/mol and MM-GBSA of -45.35 kcal/mol. (C) 2020 Elsevier B.V. All rights reserved.

关键词： Aprepitant   Physicochemical parameters   Critical micelle concentration   Micellization phenomenon   Thermodynamic properties   Interface behavior  

摘要： Aprepitant(APPT) is a drug used for suppressing nausea and vomiting. Here, an in-depth study was conducted on how the concentration of sodium salt electrolyte (NaCl or Na2SO4) and temperature (293.15-313.15 K with an interval of 5.0 K) affect the thermodynamics of APPT/HS15 micelle system in terms of the interface and micellization behavior. The critical micelle concentration (CMC) was evaluated fromsurface tension measurement. The results show that anions from the two electrolytes disrupted hydration of the surfactant and changed the CMC, dynamic light scattering, and the air-water interface parameters, thereby facilitating the formation of micelles. According to the measured standard Gibbs free energies for micellization and adsorption (Delta G(m) and Delta G(ads), respectively), micellization between APPT and HS15 was spontaneous. The temperature and electrolyte have a synergistic effect on the spontaneous micellization. We also calculated related physical and chemical parameters such as the maximum surface excess concentration (Gamma(max)), themolecular adsorption limit area (A(min)), the effect on surface tension reduction (Pi(cmc)), and the equilibrium surface free energy (Delta G(min)). In the APPT/HS15 system, electrolytes lower the energy requirement for forming micelles and makes the formed micelles more stable. Above all, NaCl and Na2SO4 can stabilize the APPT/HS15 system, which provides a reference for the clinical application of APPT. (C) 2021 Elsevier B.V. All rights reserved.

关键词： Cellulose   Hydrolysis   Glucose   P2O5   Mix-milling  

摘要： Breaking the recalcitrant structure of native crystalline cellulose is an energy demanding rate liming step in the production of glucose from cellulosic biomass. Mix-milling of lignocellulosic substrates (with P2O5) dramatically increased glucose yield. In this work, the changes of physicochemical characteristics (morphology, structure, degree of polymerization (DP), solubility) of cellulose during mix-milling (with P2O5) are correlated with glucose yield in the subsequent chemical hydrolysis process. The mix-milling enables highly efficient breakdown of cellulose I crystalline to smaller amorphous particles with low DP, which is recrystallized into cellulose II structure after water-wetting. As a result, the mix-milled cellulose (MMC) shows higher hydrolysis reactivity than that of single-milled cellulose (SMC). The results showed that small particle size, low DP, higher solubility and cellulose II content are correlated with the hydrolysis reactivity of cellulose.

关键词： Sulfasalazine   Micelles   Vesicles   Drug delivery   Cytotoxicity  

摘要： Sulfasalazine (SSZ) is a sulfa drug that is used to treat various forms of arthritis and is known for its ability to induce apoptosis in T lymphocytes and cancer cells. To enhance its solubility and efficacy, we encapsulated SSZ within a micellar/niosomal formulation. The micellar/niosomal formulation was prepared using an amphiphilic self-assembly method involving squalene (S) and tween 80 (T8) for the first time. The encapsulation and release of SSZ from the nanocarrier was characterized. The percent encapsulation efficiency of SSZ was 99.5 +/- 0.2 %, 90.5 +/- 0.5 %, and 80.5 +/- 0.8 % for the 5:100, 7.5:100, and 10:100 (w/w) ratios of SSZ:total weight of ST8 micellar/niosomal vesicles (ST8MNVs), respectively. A higher loading of 20:100 (w/w) led to SSZ diffusion from the vesicular systems within 24 h. The cytotoxic activity of the SSZ-encapsulated ST8MNVs was evaluated against different cancer cell lines. Encapsulation and the use of the nanoformulations improved the effectiveness of SSZ in promoting apoptosis in MDA-MB-231, MCF-7, and HeLa cell lines, by reducing the IC50 value by at least five folds. The high loading and encapsulation of SSZ within the micellar/niosomal formulation together with its greater water solubility enhanced the bioavailability of the drug, improving its potential for biomedical and therapeutic applications. (C) 2021 Elsevier B.V. All rights reserved.

关键词： X-ray photoelectron spectroscopy   Scanning electron microscopy   Diffuse reflectance infrared Fourier transform spectroscopy   Ceramic-based biomaterial   Hydroxyapatite  

摘要： In the present study structural characteristics and physicochemical properties of tri-component biomaterial (consisting of chitosan, beta-1,3-glucan and hydroxyapatite) seeded with mesenchymal stem cells were investigated with the use of diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). In this study we use non-conventional approach of DRIFT spectroscopy for investigating biomaterial changes under simulated physiological conditions. Particular cell-induced changes were intended to be properly evaluated with analytical methods. Abovementioned techniques allowed to precisely assess the changes on the surface of the biomaterial caused by two kinds of stem cells (ADSCs - Adipose tissue-Derived Stem Cells and BMDSCs - Bone Marrow-Derived Stem Cells) cultured directly on the surface of bioceramic-based biomaterial. The bioactivity and biocompatibility of designed bone biomaterial were demonstrated and hence it seems to be a promising scaffold used in tissue engineering. Designed chitosan, beta-1,3-glucan, and hydroxyapatite biomaterial was proven to be non-toxic, surgically handy with cellular compatibility. The obtained results are interesting and promising in terms of spectroscopic methods suitability for qualitative assessment of material-cell interactions. (C) 2021 Elsevier B.V. All rights reserved.

关键词： Chinese yam   Hydrothermal treatments   Physicochemical properties   In vitro digestibility  

摘要： The objective of this study was to investigate the effects of hydrothermal treatments (heat-moisture treatment (HMT) and annealing (ANN)) on the physicochemical properties and in vitro digestibility of yam starch and yam flour. Hydrothermal treatments decreased the pasting properties of yam starch and yam flour. Compared with yam starch, HMT significantly (p < 0.05) reduced the pasting viscosities of yam flour. Both HMT and ANN caused an increase of the gelatinization temperatures (T-o, T-p, and T-c) and a decrease of enthalpy (Delta H). The increasement in ratio of 1047/1022 cm(-1) and 995/1022 cm(-1) suggested that HMT and ANN resulted in an increase in short-range order. The crystalline pattern of all samples was still A-type, and HMT yam starch exhibited higher crystallinity (26.20%). The most significant inhibition of in vitro digestibility was found in HMT yam flour, with slowly digestible starch and resistant starch contents increasing by 3.73% and 4.40%, respectively. Hydrothermal treatments made the no-starch ingredients in yam flour agglomerate and adhere to starch granules. Confocal laser scanning microscopy showed that the starch being coated or embedded by protein was a possible reason for the differences in physicochemical properties and in vitro digestibility between yam starch and yam flour. (c) 2021 Elsevier B.V. All rights reserved.

关键词： Cell morphology   Fibroblast   Electrospun fibers   PHBV   Zeta potential  

摘要： Biodegradability or materials physicochemical stability are the key biomaterials selection parameters for various medical and tissue engineering applications. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a natural copolymer known from its biocompatibility with great support for cells growth and attachment on films and fibers. In our studies, the physicochemical properties of electrospun PHBV fibers and spin-coated films aged for 1, 4 and 8 weeks were analyzed using bulk (FTIR) and surface chemistry (XPS) methods and water contact angle. Further, we characterized the zeta potential changes after aging, by means of electrokinetic measurements, and cell responses to it, using NIH 3T3 murine fibroblasts. Colorimetric MTS cell viability test allowed the assessment of cell proliferation. Additionally, the morphology of fibroblasts and biointerfaces were studied by confocal laser and electron scanning microscopy (CLSM and SEM). These studies indicated that the activity, attachment and proliferation of fibroblasts is independent of aging of PHBV fibers and films. PHBV films show very stable zeta potential over 8 weeks of aging, opposite to PHBV fibers. Importantly, the flat film of PHBV increases cell proliferation, while the fibrous meshes are an excellent support for their stretching. The results of the study revealed clear advantages of PHBV films and fibrous meshes in cell-material interaction.

关键词： RG-I enriched pectin   Manosonication extraction   Property characterisation  

摘要： The properties of pectin extracted from mandarin citrus peels by manosonication extraction (MSp) were systematically studied and compared with pectin obtained by the conventional maceration method (CMp). The yield of MSp (25.5%) was significantly higher than that of CMp (18.3%), while MSp exhibited two Mw fraction distributions. Monosaccharide analysis demonstrated that MSp had more branched RG-I regions (78.3 mol%) than CMp (36.6 mol%) with a high content of arabinose and galactose. The branched-chain morphological characteristics of samples were directly imaged by atomic force microscopy. MSp exhibited a significantly lower degree of methoxylation than CMp by FT-IR and NMR analysis, but X-ray diffraction analysis showed little difference in the level of crystallinity. Moreover, MSp and CMp showed non-Newtonian behaviour, and the increasing order of apparent viscosities was 1.0 w/v% MSp < 1.0 w/v% CMp < 2.0 w/v% CMp < 2.0 w/v% MSp. Thermal analysis and weight loss measurements indicated MSp exhibited greater thermal stability. The results also indicated that both MSp and CMp significantly enhanced the emulsion activity at high concentrations;the emulsions containing 1.5 w/v% pectin showed no phase separation over 21 days, suggesting that MSp could be a potential effective stabiliser in the food and beverage industry. (c) 2021 Elsevier B.V. All rights reserved.

关键词： Carboxyl-functionalized ionic liquids   Acidity constant   Hydration   Molecular dynamics  

摘要： For the first time, the carboxyl-functionalized ionic liquid 1-carboxyethyl-3-methylimidazolium chloride, [C(2)COOHmim][Cl], was synthesized and characterized. The acidity constant of [C(2)COOHmim](+) was determined experimentally and by computational simulations, and the result was compared with the acidic constant of propanoic acid. Density and viscosity measurements supported with computational simulations of the dilute aqueous solutions of [C(2)COOHmim][Cl] were performed. Based on these measurements, interactions between water and newly synthesized ionic liquid were discussed. The obtained values of viscosity B-coefficient, Hepler's coefficient and results of computational simulations showed that the introduced carboxyl group enhances the hydration and structure making properties of the imidazolium-based ionic liquids. (C) 2021 Elsevier B.V. All rights reserved.