Sol–gel synthesis and thermal behavior of bioactive ferrous citrate–silica hybrid materials

Imbalance of the iron level in the body causes several diseases. In particular, the low level of iron, during pregnancy, is responsible for the iron deficiency anemia, and even of neurodegenerative diseases. Although the treatment of iron deficiency anemia with oral iron supplements has been known, this problem still afflicts many people. The aim of this work was the development of a system able to release ferrous ions in a controlled manner. Controlled drug release for medical applications, indeed, appears to be a very interesting alternative to a systemic therapy because it is assurance of treatment continuity and drug stability and optimizes drug absorption. For this purpose, ferrous citrate (Fe(II)C) was synthesized by a redox reaction between iron powder and citric acid. Fourier transform infrared spectroscopy (FTIR), 1,10-phenanthroline and sodium thiocyanate colorimetric assays confirmed that only Fe(II)C was obtained by redox reaction. Afterward, obtained Fe(II)C was embedded within a SiO2 matrix in different mass percentage, by means of a sol–gel route. FTIR spectroscopy and simultaneous thermogravimetry/first-order derivative of thermogravimetry were used to confirm the Fe(II)C presence in the silica matrix and to investigate the thermal behavior of the sol–gel materials, respectively. The bioactivity test carried out by soaking the synthesized drug delivery systems in a simulated body fluid showed that the biological properties of the silica matrix are not modified by the presence of Fe(II)C

Grape pomace polyphenols improve insulin response to a standard meal in healthy individuals: A pilot study

Dietary polyphenols have beneficial effects on glucose/lipid metabolism in subjects at high risk to develop type 2 diabetes; however, the underlying mechanisms are not clear. We aimed to evaluate: 1) the acute effects of the consumption of a drink rich in polyphenols from red grape pomace (RGPD) on glucose/insulin and triglyceride responses to a standard meal in healthy individuals, and, 2) the relationship between plasma levels of phenolic metabolites and metabolic parameters

Surface Characterization of Composite Catalysts Prepared by Sol-Gel Route

The aim of this work is to synthesize Nb-V oxide catalysts by sol gel route starting from metal alkoxides using different H2O/V ratios. Dried samples are characterized by X-ray diffraction (XRD), atomic absorption, and Brunauer-Emmett-Teller (BET) analysis. Calcination of dried materials up to 600°C in flowing air has been followed with Thermogravimetry-Fourier-transform infrared spectroscopy (TG-FTIR) spectroscopic analysis. The catalytic properties of calcined materials are tested in the oxidative dehydrogenation of ethane at 600°C. An improvement of the catalytic performances of vanadium for the gel prepared with the higher H2O/V ratio is found with respect to those of the supported catalyst due to the better interaction between vanadium and niobium

Diastereo- and enantioselective direct aldol reactions in aqueous medium: A new highly efficient proline-sugar chimeric catalyst

A new synthetic catalyst, capable of acting like an enzyme in the accomplishment of direct aldol reactions, is presented. Excellent results, in terms of chemical yields and diastereo-/enantiomeric ratios, are reported for the catalyzed additions of cyclohexanone to variously substituted benzaldehydes. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Synthesis by sol-gel technique and Antibacterial activity of bioactive hydrid SiO2 inorganic matrix by different structures of Ferrous citrate (Fe(II)C): comparative study

Abstract. The aim of this work was to characterize and compare three different structures of Ferrous citrate (Fe(II)C), amorphous, semi-crystalline and crystalline incorporated into a SiO2 inorganic matrix by sol-gel technique. On this system thus obtained, colorimetric assay was carried out to confirm the only presence of Fe2+; Fourier transform infrared spectroscopy (FTIR) confirmed not only the Fe(II)C presence in the silica matrix but also showed us the interactions among different components in the hybrid materials. The bioactivity of the synthesized hybrid materials was evaluated by the formation of a layer of hydroxyapatite on the surface of samples soaked in SBF using FTIR spectroscopy. Finally, the antibacterial properties of the hybrid materials were investigated

Waste recovery and circular economy: a resource from orange peels deriving from production of orange juice

In the perspective of bio-sustainable development and renewable resource technologies, by-products and waste from agro-industrial sector represent a relatively cheap source of material suitable for several aims, which would reduce both the amount of waste and the related costs of disposal, while producing added-value nutritional products. The processing waste of oranges find various fields of application, in fact in addition to their use in agriculture as a fertilizer, orange peels can be used to produce candied fruit. Moreover, in a very recent application with the aim to recover these industrial residues, a chemical process that allows the processing of orange peel waste has been developed. This process is useful for obtaining a purified cellulose suitable for spinning, thus creating a truly innovative and sustainable fabric (Orange Fiber). In this work, the orange peels obtained from industrial processing waste were subjected to a first hydroalcoholic extraction which allowed to obtain an extract rich in essential oils that could be used in the food sector to produce liqueurs and/or aromas, but also in the cosmetic or pharmacological sectors. Subsequently, the peels after hydroalcoholic extraction were dried and this residue represents a valuable product rich in dietetic fiber useful in nutraceutical and pharmaceutical fields. Moreover, the same product could be used as fertilizer in agriculture. In lights of this, citrus fruit processing waste can be considerate as a sustainable and renewable energy source

Extraction and purification of phycocyanin from Arthrophira platensis microalgae using a green solid-liquid extraction technology (RSLDE)

Abstract. Spirulina is a blue alga belonging to the class of Cyanobacteria. This alga is characterized by a high content of phycocyanin, a blue photosynthetic pigment belonging to the phycobiliprotein family. Phycocyanin has a lot of industrial applications, in fact, it is used as a natural dye both in the cosmetic industry and in the food and textile sectors. It is also used in the biomedical field as a fluorescent marker. Anti-inflammatory, nephroprotective and hepatoprotective properties are also reported, probably related to its antioxidant activity. However, the extraction of phycobiliproteins from cyanobacteria is a very complicated procedure due to the extreme resistance of the wall of the cellular aggregates that make up spirulina. In literature, several procedures have been used to cause rupture of cell envelopes, through cycles of freezing/thawing, sonication and rupture of the cell wall with lysozyme. However, all these methods for cell breakdown do not guarantee a high quality of the extract, due to the complexity of the mixture obtained. In order to improve the yield of recovery of phycocyanin and to reduce the extraction process time, in this work, in combination with some experimental procedures for rupture of the membrane, a green extraction technique was used, the rapid solid liquid dynamic extraction (RSLDE). This technique can generate a pressure and a consequent depression on the matrix to be extracted. The extract obtained was immediately frozen at -20°C and then lyophilized. Analyzes such as UV-VIS spectrophotometric analysis and acrylamide gel electrophoresis were performed on the sample of lyophilizate to evaluate the efficiency of the extraction and purity of phycocyanin

Various applications of processing of olive leaves waste extracted with RSLDE: a green technology

There is no waste in nature. Everything that is produced has a purpose and everything that becomes waste can be transformed into a new resource, triggering a virtuous circuit that feeds itself. The circular economy of waste means a system in which the production-consumption-disposal process is overcome to replace it with a circular model, where the final waste product is re-introduced into the circulation as a secondary raw material. The logic to follow is that after consumption and before any disposal, it is necessary to activate virtuous processes such as reduce, reuse and recycling. This work focuses on the possible uses of a vegetable waste matrix, such as olive leaves. The olive tree (Olea europaea) is a fruit tree, cultivated for more than 3,500 years for its fruits and edible oil. However, just like oil, olive leaf contains a high amount of polyphenols, in particular oleuropein, one of the most powerful natural antioxidants known and hydroxytyrosol, which also has powerful antiseptic properties. Therefore, olive leaf extracts, thanks to the presence of oleuropein associated with hydroxytyrosol, represent a powerful natural antioxidant, a valid ally of the cardiovascular system. In addition, olive leaves are an excellent regulator of the digestive system: they regulate intestinal transit and above all eliminate fungi and other unwanted parasites from our body. Starting from these premises, in this work, a green extraction technique such as rapid solid liquid dynamic extraction (RSLDE) is compared with conventional maceration to obtain an olive leaf extract rich in antioxidants to be used in various sectors

Production of polycaprolactone foams incorporating Hibiscus sabdariffa extract

Hibiscus sabdariffa is a plant characterized by a high content of antioxidant molecules; its aqueous extract (karkadé) offers considerable potential benefits during the healing process. Since most antioxidant molecules are sensitive to thermo-oxidative degradation during extraction and encapsulation processes, this study proposes a novel application to preserve karkadé inhibition power, by entrapping it in poly-ε-caprolactone (PCL) foams. Karkadé was obtained using Rapid Solid-Liquid Dynamic Extraction, processed at 20 °C and below 10 bar. The concentration of karkadé solid residue was 195.0 ± 4.6 g/L, while the reduction of the antioxidant inhibition power was 26.0 ± 1.4 % after 450 min of extraction, much greater than native karkadé extracted using other techniques (>60 %). Entrapment of karkadé occurred during the preparation of 3 mg/mL PCL in an acetone solution, which solidified upon solvent evaporation at 20 °C, obtaining a disk. Then, the disk was foamed using CO2 as physical blowing agent at optimized parameters (45 °C, 100 bar, and sorption for 60 min). Foam density of 180 kg/m3, cell number density of 4.1E06 cell/cm3, and an average pore dimension of 56 ± 28 μm were obtained, with karkadé entrapment efficiency up to 97 %. This study focused on manipulating PCL foam cells density and diameter, to influence release time of karkadé extract into an aqueous receiving medium. Different cells diameters and number density were achieved by varying sorption time of CO2 in PCL, set at 30, 60, and 90 min, respectively. Sorption time of 60 min was demonstrated to be sufficient for creating a uniform porous structure, while a 30 min sorption time resulted in a delayed release rate. Foams were soaked in cell culture medium, which was then put in contact with human keratinocytes, thus demonstrating their biocompatibility up to 9 days

Characterization of Volatile Organic Compounds (VOC) in wet-white and metal-free leathers

Content: As it is known in the tanning sector, in recent times, the so-called wet-white and/or metal-free concepts have had a certain increase. For example, in the automotive sector, the wet-white tanning system, carried out with glutaraldehyde and tannins, has been widely diffused. In fact, car manufacturers offer, for interior furnishings, leather not only for high-end cars but increasingly also in the lower segments. The components on which the leather upholstery is applied are mainly steering wheel, seats, dashboard and panels. Therefore, the use of leather also in this context must be able to meet both the aesthetic/performance criteria and the environmental ones; environmental criteria should also consider the air quality of the interior of a motor vehicle. In practice, the interior furniture consisting of finished leather must be able to release a few volatile substances and, at the same time, provide a typical smell of leather. Considering, therefore, the diffusion of alternative chrome tanning systems for the different uses, in this work, wet-white (glutaraldehyde and tannins) will be investigated, both from the point of view of the performance characteristics and from the ecotoxicological ones. and leathers deriving from the latest generation of metal-free tanning. For the characterization of Volatile Organic Compounds (VOC) the GC-MS will be used coupled with the 'Purge and Trap' technique with the aim of obtaining information on the new substances used in the wetwhite / metal free production process and then avoiding undesired effects during use (eg bad smell, SVHC substances, etc.) Take-Away: metal-free automotive VO