The Antioxidant and Anti-Inflammatory Properties of Wild Bilberry Fruit Extracts Embedded in Mesoporous Silica-Type Supports: A Stability Study.

Polyphenolic extracts from wild bilberries (Vaccinium myrtillus L.) have shown antioxidant and anti-inflammatory effects, but they are prone to degradation when exposed to environmental factors, limiting their use in biomedical applications. To overcome this issue, this study proposed the embedding of wild bilberry fruit ethanolic extracts in pristine mesoporous silica functionalized with organic groups (mercaptopropyl and propionic acid), as well as coated with fucoidan, a biopolymer. Herein, we report a stability study of free and incorporated extracts in mesoporous silica-type supports in high-humidity atmospheres at 40 °C up to 28 days, using HPLC analysis, thermal analysis, and radical scavenging activity determination. Better chemical and thermal stability over time was observed when the extracts were incorporated in mesoporous silica-type supports. After 12 months of storage, higher values of antioxidant activity were determined for the extract embedded in the supports, silica modified with mercaptopropyl groups (MCM-SH), and fucoidan-coated silica (MCM-SH-Fuc) than that of the free extract due to a synergistic activity between the support and extract. All encapsulated extracts demonstrated remarkable effects in reducing NO production in LPS-stimulated RAW 264.7 cells. The treatment with extract embedded in MCM-SH-Fuc in a dose of 10 µg/mL surpassed the effect of free extract in the same concentration. For the extract encapsulated in an MCM-SH support, a lower IC50 value (0.69 µg/mL) towards COX-2 was obtained, comparable with that of Indomethacin (0.6 µg/mL). Also, this sample showed a higher selectivity index (2.71) for COX-2 than the reference anti-inflammatory drug (0.98). The developed formulations with antioxidant and anti-inflammatory properties could be further used in nutraceuticals.

Determination of Fumonisin B1 in maize using molecularly imprinted polymer nanoparticles-based assay.

Fumonisin B1 (FB1) is a carcinogenic mycotoxin produced by Fusarium species contaminating maize. At present, fumonisin determination is performed using costly and demanding chromatography techniques or immunoassays. Recently, a molecularly imprinted polymer nanoparticles (nanoMIPs) - based assay (MINA) has been developed for FB1 detection. Herein, we have applied MINA for the determination of FB1 in naturally contaminated maize samples and results were compared with those obtained with ELISA and a reference HPLC method (AOAC No. 2001.04). The nanoMIPs as a recognition element mimicking antibodies used in ELISA were produced by solid phase synthesis and used in MINA for FB1 determination in 53 maize samples. As a result, 18 maize samples were contaminated with FB1 at levels higher than 0.25 mg/kg. Fumonisin concentrations from samples measured by MINA were well correlated with those using ELISA and HPLC. Therefore, MINA could be used as an alternative technique for FB1 determination in maize.

Raman spectroscopy combined with advanced chemometric methods: A new approach for detergent deformulation.

Deformulation of a commercial surfactant mixture using Raman spectroscopy and advanced chemometric tools have been investigated. Since the use of surfactants is drastically expanding, their fine identification and quantification are required for quality control and regulation. Dilution of the detergent mixtures combined with Raman spectroscopy for signal extraction tools allowed the extraction of the first information concerning the composition of the mixture. The raw materials identified were thus used in an experimental design to obtain a robust model for the determination of detergent composition. The combination of chemometric tools (independent component analysis and Partial Least Square) and spectroscopic methods provided pertinent information for detergent composition. This methodology can easily be transposed to the industrial world.

Biopatterning of antibodies on poly(pyrrole)-nanowires using nanocontact printing: Surface characterization.

A highly performant patterning of antibodies using poly(pyrrole) nanowires (PPy-NWs) was devised on thermoplastic surfaces based on silane derivatives. The PPy-NWs were fabricated employing nanocontact printing and controlled chemical polymerization (nCP-CCP) on poly(ethylene terephthalate), cyclic olefin copolymer, poly(ethylene 2,6-naphthalate), and polyimide. The technique used a commercial compact disk as a template (mold) to produce nanopatterned polydimethylsiloxane stamps. The nanopatterned stamp was then employed to print PPy-NWs. The printing technique permits to control PPy-NW size and shape. The dimensions of the printed PPy-NWs were: 785 ±â€¯1.5 nm (width), 174 ±â€¯2.1 nm (height), and a separation between wires of 540 ±â€¯1.2 nm. The printing process and the surface properties of the PPy-NWs pattern were successfully characterized by scanning electron microscopy and atomic force microscopy. Biopatterning was completed by the chemical immobilization of the specific anti-human interleukin-10 monoclonal antibody on PPy-NW using gluteraldehyde. The biocomposite was tested using qualitative immunocytokine bioassay, which is of great importance for early stage cancer detection. For that purpose, fluorescent imaging was used to certify the immunodetection of the recombinant human interleukin-10. The biopatterning technology provides a simple, low cost and one step procedure. Undoubtedly, this new technology will impact and provide an alternative to the current techniques applied for bioengineering and nanopatterning.

Pectin gelation with chlorhexidine: Physico-chemical studies in dilute solutions.

Low methoxyl pectin is known to gel with divalent cations (e.g. Ca(2+), Zn(2+)). In this study, a new way of pectin gelation in the presence of an active pharmaceutical ingredient, chlorhexidine (CX), was highlighted. Thus chlorhexidine interactions with pectin were investigated and compared with the well-known pectin/Ca(2+) binding model. Gelation mechanisms were studied by several physico-chemical methods such as zeta potential, viscosity, size measurements and binding isotherm was determined by Proton Nuclear Magnetic Resonance Spectroscopy ((1)H NMR). The binding process exhibited similar first two steps for both divalent ions: a stoichiometric monocomplexation of the polymer followed by a dimerization step. However, stronger interactions were observed between pectin and chlorhexidine. Moreover, the dimerization step occurred under stoichiometric conditions with chlorhexidine whereas non-stoichiometric conditions were involved with calcium ions. In the case of chlorhexidine, an additional intermolecular binding occurred in a third step.

Determination of testosterone and its photodegradation products in surface waters using solid-phase extraction followed by LC-MS/MS analysis.

The formation of several by-products from the photodegradation of testosterone was previously observed under laboratory conditions. The objectives of the manuscript were to complete the identification of testosterone's photoproducts and to develop an analytical method for the detection of testosterone as well as its three main photoproducts in natural sunlit surface waters. To accomplish these tasks, an efficient extraction method was developed based on solid-phase extraction, followed by the use of liquid chromatography coupled to tandem mass spectrometry, a selective and sensitive detection method. This analytical procedure has the capability of detecting target analytes in the ng/L range, with recoveries above 80 %. The methodology was successfully applied to the analysis of testosterone and its photoproducts in several surface waters.

Light induced degradation of testosterone in waters.

The degradation of testosterone under simulated irradiations was studied in phosphate buffers and in natural waters at various excitation wavelengths. The quantum yield of photolysis was significantly lower at 313 nm (2.4 x 10(-3)) than at 254 nm (0.225). The formation of several photoproducts was observed, some of them being rapidly transformed in turn while others show higher stability towards subsequent irradiations. The nature of the main products was tentatively identified, both deduced from their spectral and spectrometric data and by comparison with synthesised standard compounds. Among the obtained photoproducts, the main one is possibly a spiro-compound, hydroxylated derivative of testosterone originating from the photohydratation of the enone group. The photodegradation pathway includes also photorearrangements. One of them leads to (1,5,10)-cyclopropyl-17beta-hydroxyandrostane-2-one. The pH of the water does not seem to affect the rate of phototransformation and the nature of the by-products.