Novel strategy for encapsulation and targeted delivery of poorly water-soluble active substances

Carriers for targeted delivery and controlled release of poorly water-soluble active substances (PWSAS) are facing three challenges: (a) the encapsulation issues, (b) limitations of PWSAS water solubility, and (c) burst drug release which can be pharmacologically dangerous and economically inefficient. The present study brings a novel strategy for encapsulation and controlled release of PWSAS—caffeine in concentrations which are higher than its maximal water solubility without the possibility of burst effect. The modification of hydrophilic carrier based on poly(methacylic acid) was done using casein and liposomes. To further increase the maximal caffeine loading inside the carrier nicotinamide was used. The release study of the encapsulated PWSAS was elaborated with respect to morphology of the carriers and interactions that could be established between its structural components. The carriers swelling and the release of caffeine and nicotinamide were also investigated depending on caffeine concentration, the presence of different liposomal formulations and the volume ratio of liposomal formulation, in three media with different pH simulating the path of the carrier through the human gastrointestinal tract. The synthesized carriers are promising candidates for encapsulation of PWSAS in concentrations which are higher than its maximal water solubility and for the targeted delivery of those dosages.     

Validation of a Gas Chromatography-Mass Spectrometry Method for the Measurement of the Redox State Metabolic Ratios Lactate/Pyruvate and β-Hydroxybutyrate/Acetoacetate in Biological Samples

The metabolic ratios lactate/pyruvate and β-hydroxybutyrate/acetoacetate are considered valuable tools to evaluate the in vivo redox cellular state by estimating the free NAD+/NADH in cytoplasm and mitochondria, respectively. The aim of the current study was to validate a gas-chromatography mass spectrometry method for simultaneous determination of the four metabolites in plasma and liver tissue. The procedure included an o-phenylenediamine microwave-assisted derivatization, followed by liquid-liquid extraction with ethyl acetate and silylation with bis(trimethylsilyl)trifluoroacetamide:trimethylchlorosilane 99:1. The calibration curves presented acceptable linearity, with a limit of quantification of 0.001 mM for pyruvate, β-hydroxybutyrate and acetoacetate and of 0.01 mM for lactate. The intra-day and inter-day accuracy and precision were within the European Medicines Agency’s Guideline specifications. No significant differences were observed in the slope coefficient of three-point standard metabolite-spiked curves in plasma or liver and water, and acceptable recoveries were obtained in the metabolite-spiked samples. Applicability of the method was tested in precision-cut liver rat slices and also in HepG2 cells incubated under different experimental conditions challenging the redox state. In conclusion, the validated method presented good sensitivity, specificity and reproducibility in the quantification of lactate/pyruvate and β-hydroxybutyrate/acetate metabolites and may be useful in the evaluation of in vivo redox states.     

碳纳米管修饰电极的制备及其对NADH的电催化氧化

采用丝网印刷技术,制备出羧基化多壁碳纳米管修饰的丝网印刷碳电极,并采用循环伏安法研究了该电极对还原型烟酰胺腺嘌呤二核苷酸(NADH)的电催化氧化性能.结果表明,与未修饰丝网印刷碳电极相比,多壁碳纳米管修饰丝网印刷碳电极显著降低了NADH的氧化峰电位,消除了反应产物对电极的污染及其它电化学反应对测量的干扰.将修饰电极与流...     

烟酰胺配合物的合成及晶体形态的电镜观察

为了进一步了解烟酰胺配体的配位特征和结构特点，对配合物Mn(Nica)2Cl2,Fe(Nica)2Cl2,Co(Nica)2Cl2,Ni(Nica)2Cl2,Cu(Nica)2Cl2和Zn(Nica)2Cl2进行了合成和红外光谱、透射电镜、扫描电镜的表征，烟酰胺以吡啶氮与金属离子配位，Mn(Ⅱ），Fe(Ⅱ),Co(Ⅱ)，Ni(Ⅱ）配合物为六方晶体结构，Cu(Ⅱ）配合物为金刚石立方晶体结构。     

Antimicrobial activity of Elettaria cardamomum: Toxicity,biochemical and histological studies

Elettaria cardamomum is one of the most broadly used spices in Moroccan gastronomy. Its antimicrobial activity against both Gram-positive and Gram-negative bacterial species was demonstrated. Likewise, its toxicity was investigated on Swiss albinos mice. Daily, mice were treated orally with 0.003 and 0.3 mg during 7 days. Plasmatic markers and antioxidant defence systems were assessed and histological alterations were evaluated. A significant increase in creatine phosphokinase level was observed. The microscopic evaluation shows that E. cardamomum induce morphological perturbation in mice’s heart. The results show also an inhibitory effect of glyceraldehyde 3-phosphate dehydrogenase and an important increase in the level of thiobarbituric acid reactive substances, succinate dehydrogenase and catalase activities. Results show that E. cardamomum induces toxicity at 0.3 mg/g mouse and affect energy metabolism and oxidative stress.     

Identification of phenolic compounds isolated from pigmented rices and their aldose reductase inhibitory activities

Two anthocyanins (cyanidin-3-O-β-glucoside and peonidin-3-O-β-glucoside) and other phenolic (ferulic acid) were, respectively isolated from black and pigmented brown rices (Oryza sativa L. japonica) and their complete structures were determined by spectroscopic analyses (H NMR, C NMR and MALDI MASS). The HPLC profile of anthocyanins extracted from black rice showed cyanidin-3-O-β-glucoside as the first peak (85%) and peonidin 3-O-β-d-glucoside as the second (15%), while that of pigmented brown rice showed ferulic acid as the first peak (85.7%) and tocols as the second (14.3%). Several tocols were isolated and identified from the unsaponifiable fractions of both rices having some difference on their structures and amounts. The aldose reductase inhibitory activity of isolated compounds was in the following decreasing order: cyanidin-3-glucoside > quercetin > ferulic acid > peonidin-3-glucoside > tocopherol.     

Growth of microalgae using CO2 enriched air for biodiesel production in supercritical CO2

The optimum conditions for lipids productivity and CO₂ fixation of two freshwater strains, namely Chlorella sp. and Pseudochlorococcum sp. and a marine strain; namely Nannochlorpsis sp. have been determined in this work. The species were grown autotrophically under aeration with different CO₂ concentrations, ranging from 0.04 to 2% (v/v). The growth was tested in nitrogen sufficient and deficient media at different salinities (0.49–680 mM) and temperatures of 27 and 31 °C. The optimum CO₂ enrichment was found to be 1% (v/v) in both media. Nitrogen starvation resulted in an increase in lipid contents, but at lower growth rate, which resulted in a lower overall lipid productivity. The experimental data were used to determine the kinetic parameters of Haldane model. The Chlorella sp. grew well at salinity levels of up to 460 mM. The highest CO₂ biofixation rate was observed when Chlorella sp. was grown at 27 °C in seawater (230 mM NaCl).Lipids were extracted from harvested marine strain, Nannochlorpsis sp., and enzymatically transesterified to produce biodiesel in supercritical CO₂ (SC–CO₂) medium. It was found that the conversion of biodiesel produced from microalgae lipids was 35% higher than that achieved using lamb fat in a similar system.     

基于计算机模拟探究鱼类烟酰胺腺嘌呤二核苷酸脱氢酶源活性肽抗运动疲劳的功效

为了研究鱼类烟酰胺腺嘌呤二核苷酸脱氢酶（Nicotinamide Adenine Dinucleotide Dehydrogenase,NADH Dehydrogenase）源活性肽抗运动疲劳的功效,该研究利用计算机模拟水解5种我国常见鱼类中的NADH Dehydrogenase蛋白亚基,将模拟水解得到的寡肽与乳酸脱氢酶（Lactate Dehydrogenase,LDH）、肌酸激酶（Creatine Kinase,CK）分别进行分子对接,确定与LDH和CK具有超高亲和力的寡肽（对接分数≤-160）,并利用Pymol、Ligplot+软件分析寡肽与LDH和CK分子间相互作用机制。结果显示,5种鱼类的7种不同NADH Dehydrogenase蛋白亚基经计算机模拟水解和分子对接后共获得72个超高亲和力寡肽,其中,与LDH、CK均具有超高亲和力的寡肽共36种,对接分数最高且出现次数最多的寡肽是PTIW（-198.762、-204.400）。研究结果为提升鱼类蛋白质的高值化利用以及开发抗疲劳功能食品提供理论参考。     

Polymer-Based Module for NAD+ Regeneration with Visible Light

The regeneration of enzymatic cofactors by cell-free synthetic modules is a key step towards producing a purely synthetic cell. Herein, we demonstrate the regeneration of the enzyme cofactor NAD⁺ by photo-oxidation of NADH under visible-light irradiation by using metal-free conjugated polymer nanoparticles. Encapsulation of the light-active nanoparticles in the lumen of polymeric vesicles produced a fully organic module able to regenerate NAD⁺ in an enzyme-free system. The polymer compartment conferred physical and chemical autonomy to the module, allowing the regeneration of NAD⁺ to occur efficiently, even in harsh chemical environments. Moreover, we show that regeneration of NAD⁺ by the photocatalyst nanoparticles can oxidize a model substrate, in conjunction with the enzyme glycerol dehydrogenase. To ensure the longevity of the enzyme, we immobilized it within a protective silica matrix; this yielded enzymatic silica nanoparticles with enhanced long-term performance and compatibility with the NAD⁺-regeneration system.