Supercritical CO2 Assisted Impregnation of Ibuprofen on Medium-Chain-Length Polyhydroxyalkanoates (mcl-PHA)

In this work, we propose the utilization of scCO₂ to impregnate ibuprofen into the mcl-PHA matrix produced by Pseudomonas chlororaphis subs. aurantiaca (DSM 19603). The biopolymer has adhesive properties, is biocompatible and has a melting temperature of 45 °C. Several conditions, namely, pressure (15 and 20 MPa) and impregnation time (30 min, 1 h and 3 h) were tested. The highest ibuprofen content (90.8 ± 6.5 mg of ibuprofen/g_PHA) was obtained at 20 MPa and 40 °C, for 1 h, with an impregnation rate of 89 mg/(g·h). The processed mcl-PHA samples suffered a plasticization, as shown by the decrease of 6.5 °C in the T_g, at 20 MPa. The polymer’s crystallinity was also affected concomitantly with the matrices’ ibuprofen content. For all the impregnation conditions tested the release of ibuprofen from the biopolymer followed a type II release profile. This study has demonstrated that the mcl-PHA produced by P. chlororaphis has a great potential for the development of novel topical drug delivery systems.     

Quality Evaluation of Light- and Dark-Colored Hungarian Honeys,Focusing on Botanical Origin,Antioxidant Capacity and Mineral Content

Melissopalynology, antioxidant capacity and mineral and toxic element contents were analyzed in eight types of Hungarian honeys. Based on color, two groups were distinguished: light honeys comprised acacia, amorpha, phacelia and linden honeys; while dark honeys included sunflower, chestnut, fennel and sage honeys, with 100 to 300 and 700 to 1500 mAU, respectively. The unifloral origin of each sample was supported using pollen analysis. The absorbance of honey correlated positively with antioxidant capacity determined by three different methods (TRC, DPPH, ORAC), and also with mineral content. The exception was the light amber linden honey with significantly higher K content and antiradical activity than other light honeys. The Mn, Zn and Fe contents were the highest in chestnut, sunflower and fennel honeys, respectively. The black meadow sage honey performed best regarding the content of other elements and antioxidant activity. The concentrations of several toxic elements were below the detection limit in the samples, indicating their good quality. The principal component analysis (PCA) revealed correlations between different antioxidant assays and minerals, and furthermore, confirmed the botanical authentication of the honeys based on the studied parameters. To our best knowledge, the present study is the first to provide a complex analysis of quality parameters of eight unifloral Hungarian honeys.     

Ultrasound-Assisted Microencapsulation of Soybean Oil and Vitamin D Using Bare Glycogen Nanoparticles

Ultrasonically synthesized core-shell microcapsules can be made of synthetic polymers or natural biopolymers, such as proteins and polysaccharides, and have found applications in food, drug delivery and cosmetics. This study reports on the ultrasonic synthesis of microcapsules using unmodified (natural) and biodegradable glycogen nanoparticles derived from various sources, such as rabbit and bovine liver, oyster and sweet corn, for the encapsulation of soybean oil and vitamin D. Depending on their source, glycogen nanoparticles exhibited differences in size and ‘bound’ proteins. We optimized various synthetic parameters, such as ultrasonic power, time and concentration of glycogens and the oil phase to obtain stable core-shell microcapsules. Particularly, under ultrasound-induced emulsification conditions (sonication time 45 s and sonication power 160 W), native glycogens formed microcapsules with diameter between 0.3 μm and 8 μm. It was found that the size of glycogen as well as the protein component play an important role in stabilizing the Pickering emulsion and the microcapsules shell. This study highlights that native glycogen nanoparticles without any further tedious chemical modification steps can be successfully used for the encapsulation of nutrients.     

Development and Validation of QuEChERS Followed by UHPLC-ToF-MS Method for Determination of Multi-Mycotoxins in Pistachio Nuts

Pistachios are one of the types of tree nut fruits with the highest mycotoxin contamination, especially of aflatoxins, worldwide. This study developed a Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method that was followed by Ultra-High Performance Liquid Chromatography combined with Time-of-Flight Mass Spectrometry (UHPLC–ToF-MS) for the determination of mycotoxins in pistachios. Different approaches to dispersive solid phase extraction as a clean-up method for high lipid matrices were evaluated. For this, classic sorbents such as C18 (octadecyl-modified silica) and PSA (primary secondary amine), and new classes of sorbents, namely EMR-Lipid (enhanced matrix removal-lipid) and Z-Sep (modified silica gel with zirconium oxide), were used. The QuEChERS method, followed by Z-Sep d-SPE clean-up, provided the best analytical performance for aflatoxins (AFB1, AFB2, AFG1 and AFG2), ochratoxin A (OTA), zearalenone (ZEA), toxin T2 (T2) and toxin HT-2 (HT2) in pistachios. The method was validated in terms of linearity, sensitivity, repeatability, interday precision and recovery; it achieved good results according to criteria imposed by Commission Regulation (EC) no. 401/2006. The method was applied to real samples and the results show that pistachios that are available in Portuguese markets are safe from mycotoxins that are of concern to human health.     

Cyclodextrin Polymers as Delivery Systems for Targeted Anti-Cancer Chemotherapy

In the few last years, nanosystems have emerged as a potential therapeutic approach to improve the efficacy and selectivity of many drugs. Cyclodextrins (CyDs) and their nanoparticles have been widely investigated as drug delivery systems. The covalent functionalization of CyD polymer nanoparticles with targeting molecules can improve the therapeutic potential of this family of nanosystems. In this study, we investigated cross-linked γ- and β-cyclodextrin polymers as carriers for doxorubicin (ox) and oxaliplatin (Oxa). We also functionalized γ-CyD polymer bearing COOH functionalities with arginine-glycine-aspartic or arginine moieties for targeting the integrin receptors of cancer cells. We tested the Dox and Oxa anti-proliferative activity in the presence of the precursor polymer with COOH functionalities and its derivatives in A549 (lung, carcinoma) and HepG2 (liver, carcinoma) cell lines. We found that CyD polymers can significantly improve the antiproliferative activity of Dox in HepG2 cell lines only, whereas the cytotoxic activity of Oxa resulted as enhanced in both cell lines. The peptide or amino acid functionalized CyD polymers, loaded with Dox, did not show any additional effect compared to the precursor polymer. Finally, studies of Dox uptake showed that the higher antiproliferative activity of complexes correlates with the higher accumulation of Dox inside the cells. The results show that CyD polymers could be used as carriers for repositioning classical anticancer drugs such as Dox or Oxa to increase their antitumor activity.     

Prediction of the behaviour of organic pollutants using cloud point extraction

A preconcentration study based on the cloud point phenomenon was carried out for a set of triazine herbicides, three of them chloro-substituted and three of them methylthio-substituted. Concentration factors and recoveries were calculated as function of the percentage of the non-ionic surfactant Triton X-114 employed. From these values, obtained from a cloud point extraction (CPE) procedure, the distribution coefficient between the Triton X-114 micelles and water, Kc, prior to CPE was calculated for each triazine and related to the corresponding octanol-water partition coefficient, Kow. In order to confirm the results obtained with the triazine herbicides, two sets of data from chemically different organic pollutants--organophosporous and chlorophenols--obtained from the literature were assessed, concluding that they display a similar behaviour to that of the triazine herbicides. This can be used to predict the CPE behaviour of other organic pollutants from their octanol-water partition coefficients. The Kc values were compared with the analyte concentration ratio in the surfactant-rich phase and aqueous phase (Ksa) with a view to obtaining a link between the analyte behaviour prior to and after cloud point extraction procedures.     

Characterization of Nested Hollow Inorganic Fullerene-like Tungsten Disulfide Nanoparticles Prepared by Solid-Gas Reaction

Non-carbon inorganic fullerene-like(IF) nanoscale materials have recently attracted intense interest due to their nested hollow and nanotube structures,In this letter,IF-WS2 nanoparticles prepared by solid-gas reaction were characterized by X-ray diffraction,Scanning electron microscopy and transmission electron microscopy.The results show that the IF-WS2 nanoparticles have a nested hollow closed spherical structure with diameter of 100-150mm.     

Characterization of Collagen/Lipid Nanoparticle–Curcumin Cryostructurates for Wound Healing Applications

Curcumin‐loaded collagen cryostructurates have been devised for wound healing applications. Curcumin displays strong antioxidant, antiseptic, and anti‐inflammatory properties, while collagen is acknowledged for promoting cell adhesion, migration and differentiation. However, when curcumin is loaded directly into collagen hydrogels, it forms large molecular aggregates and clogs the matrix pores. A double‐encapsulation strategy is therefore developed by loading curcumin into lipid nanoparticles (LNP), and embedding these particles inside collagen scaffolds. The resulting collagen/LNP cryostructurates have an optimal fibrous structure with ≈100 µm average pore size for sustaining cell migration. Results show that collagen is structurally unaltered and that nanoparticles are homogeneously distributed amidst collagen fibers. Hydrogels soaked in saline buffer release about 20 to 30% of their nanoparticles content within 24 h, while achieved 100% release after 25 days. When exposed to NIH 3T3 fibroblasts, these hydrogels provide a satisfactory scaffold for cell interaction as early as 4 h after seeding, with no cytotoxic counter effect. These positive features make the collagen/lipid cryostructurates a promising material for further use in wound healing.     

Organic-Free Interzeolite Transformation in the Absence of Common Building Units

Zeolite crystals can be used as seeds or aluminosilicate sources in syntheses to control polymorphs and/or reduce the quantity of organics used as structure-directing agents. A frequently invoked hypothesis for interzeolite transformations is that zeolites share some underlying similarity in structure, most notably in cases pertaining to organic-free syntheses. Herein, we show for the first time that ZSM-5 (MFI) can be directly obtained from USY (FAU) through an interzeolite transformation between parent–daughter structures lacking common building units in the absence of a structure-directing agent and seeds. We show that interzeolite transformation leads to a crystalline product with fewer defects. Our findings also reveal that ZSM-5 is a metastable intermediate that undergoes further transformation to mordenite (MOR) and quartz. The MFI-to-MOR transition is counter to reported trends for which transformations lead to structures with reduced molar volume. Herein, we propose mechanistic arguments that suggest the driving force for interzeolite transformation is more complex than guidelines posited in the literature.     

Comparative study of separation and determination of triazines by micellar electrokinetic capillary chromatography and nonaqueous capillary electrophoresis: application to residue analysis in natural waters

The separation and determination of a mixture of chloro- and methylthiotriazines in water samples by both micellar electrokinetic capillary chromatography (MEKC) and nonaqueous capillary zone electrophoresis (NA-CZE) were compared. The characteristics of both methods proved to be very similar in terms of separation efficiency and analysis times, but application of these methods for the analysis of triazines in natural waters, with a prior preconcentration step, revealed significant differences. A preconcentration step by solid-phase extraction (SPE) with Oasis HLB cartridges was accomplished for the determination of triazines at sub-ppb levels in drinking and river waters; when NA-CZE was used after this SPE step, electropherograms with fewer interferences and more stable baselines were obtained than when separation was carried out using MEKC. Another aspect related to the application to real samples was the lack of precision encountered upon evaluating the electrophoretic signals generated when using SPE coupled with NA-CZE. Here, we demonstrate the importance of choosing an appropriate internal standard for analyte quantification. It is recommended that a triazine belonging to the same family as that of the triazine to be determined should be used as internal standard.