The development of green technologies and bioprocesses such as solid-state fermentation (SSF) is important for the processing of macroalgae biomass and to reduce the negative effect of
spp. on marine ...ecosystems, as well as the production of compounds with high added value such as fungal proteins. In the present study,
spp. biomass was subjected to hydrothermal pretreatments at different operating temperatures (150, 170, and 190 °C) and pressures (3.75, 6.91, and 11.54 bar) for 50 min, obtaining a glucan-rich substrate (17.99, 23.86, and 25.38 g/100 g d.w., respectively). The results indicate that
pretreated at a pretreatment temperature of 170 °C was suitable for fungal growth. SSF was performed in packed-bed bioreactors, obtaining the highest protein content at 96 h (6.6%) and the lowest content at 72 h (4.6%). In contrast, it was observed that the production of fungal proteins is related to the concentration of sugars. Furthermore, fermentation results in a reduction in antinutritional elements, such as heavy metals (As, Cd, Pb, Hg, and Sn), and there is a decrease in ash content during fermentation kinetics. Finally, this work shows that
can assimilate nutrients found in the pretreated
spp. to produce fungal proteins as a strategy for the food industry.
The biological production of H2 represents a renewable and eco-friendly energy alternative compared to fossil fuels. However, its production from lignocellulose involves the use of expensive ...enzymatic complexes. In the present work, the production of H2 from pretreated agave biomass was evaluated by means of a Consolidated Bioprocess (CBP). This strategy was carried through the interaction of cellulose-degrading microorganisms obtained from bovine ruminal fluid (BRF) capable of enhancing H2 production by Clostridium acetobutylicum. The results obtained show the capacity of BRF to hydrolyze the acid pretreated agave, improving the production of H2 in the experiments where the inoculum of Clostridium was greater. According to the results, production of H2 is significantly affected by the increase of the solids loading, obtaining a maximum H2 production at a 10% of solids loading, pH 5.5 and 35 °C, representing a yield of 150 L of H2 per Kg of biomass in 264 h.
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•BRF was used to hydrolyze pretreated agave and replace the enzymatic complexes.•The acid pretreatment increased significantly the enzymatic digestibility (94.3%).•DRX and SEM showed important structural changes in agave pretreated with acid.•BRF was able to release concentrations greater than 40 g/L of glucose.•The interaction of BRF and C. acetobutylicum favored H2 production.
Goethite-titania (α-FeOOH-TiO
) composites were prepared by co-precipitation and mechanical milling. The structural, morphological and optical properties of as-synthesized composites were ...characterized by X-ray powder diffraction, scanning electron microscopy and UV-Vis diffuse reflectance spectroscopy, respectively. α-FeOOH-TiO
composites and TiO
-P25, as reference, were evaluated as photocatalysts for the disinfection of
under UV or visible light in a stirred tank reactor. α-FeOOH-TiO
exhibited better photocatalytic activity in the visible region than TiO
-P25. The mechanical activation increased the absorption in the visible range of TiO
-P25 and the photocatalytic activity of α-FeOOH-TiO
. In the experiments with UV light and α-FeOOH-TiO
, mechanically activated, a 5.4 log-reduction of bacteria was achieved after 240 min of treatment. Using visible light the α-FeOOH-TiO
and the TiO
-P25 showed a 3.1 and a 0.7 log-reductions at 240 min, respectively. The disinfection mechanism was studied by ROS detection and scavenger experiments, demonstrating that the main ROS produced in the disinfection process were superoxide radical anion, singlet oxygen and hydroxyl radical.
In this work, hydrogels based on semi‐interpenetrating polymeric networks (semi‐IPN) based on collagen‐polyurethane‐alginate were studied physicochemically and from different approaches for ...biomedical application. It was determined that the matrices in the hydrogel state are crosslinked by the formation of urea and amide bonds between the biopolymer chains and the polyurethane crosslinker. The increment in alginate content (0–40 wt%) significantly increases the swelling capacity, generating semi‐crystalline granular structures with improved storage modulus and resistance to thermal, hydrolytic, and proteolytic degradation. The in vitro bioactivity results indicated that the composition of these novel hydrogels stimulates the metabolic activity of monocytes and fibroblasts, benefiting their proliferation; while in cancer cell lines, it was determined that the composition of these biomaterials decreases the metabolic activity of breast cancer cells after 48 h of stimulation, and for colon cancer cells their metabolic activity decreases after 72 h of contact for the hydrogel with 40 wt% alginate. The matrices show a behavior of multidose release of ketorolac, and a higher concentration of analgesic is released in the semi‐IPN matrix. The inhibition capacity of Escherichia coli is higher if the polysaccharide concentration is low (10 wt%). The in vitro wound closure test (scratch test) results indicate that the hydrogel with 20 wt% alginate shows an improvement in wound closure at 15 days of contact. Finally, the bioactivity of mineralization was evaluated to demonstrate that these hydrogels can induce the formation of carbonated apatite on their surface. The engineered hydrogels show biomedical multifunctionality and they could be applied in soft and hard tissue healing strategies, anticancer therapies, and drug release devices.
Diabetic foot ulcers are a serious complication of uncontrolled diabetes, emphasizing the need to develop wound healing strategies that are not only effective but also biocompatible, biodegradable, ...and safe. We aimed to create biomatrices composed of semi‐interpenetrated polymer networks of collagen, polyurethane, and dextran, to enhance the wound healing process. The hydrogels were extensively characterized by various analytical techniques, including analysis of their structure, crystallinity, thermal properties, gelation process, reticulation, degradation, cell proliferation, and healing properties, among others. Semi‐interpenetrated hydrogels containing dextran at levels of 10%, 20%, and 30% exhibited porous interconnections between collagen fibers and entrapped dextran granules, with a remarkable crosslinking index of up to 94% promoted by hydrogen bonds. These hydrogels showed significant improvements in mechanical properties, swelling, and resistance to proteolytic and hydrolytic degradation. After 24 h, there was a significant increase in the viability of several cell types, including RAW 264.7 cells, human peripheral blood mononuclear cells, and dermal fibroblasts. In addition, these hydrogels demonstrated an increased release of interleukin‐10 and transforming growth factor‐beta1 while inhibiting the release of monocyte chemotactic protein‐1 and tumor necrosis factor‐alpha after 72 h. Furthermore, these hydrogels accelerated the wound healing process in diabetic rats after topical application. Notably, the biomaterial with 20% dextran (D20) facilitated wound closure in only 21 days. These results highlight the potential of the D20 hydrogel, which exhibits physicochemical and biological properties that enhance wound healing by inhibiting inflammation and fibrillogenesis while remaining safe for application to the skin.
Synthesis, characterization and biological evaluation of collagen‐polyurethane‐dextran hydrogels.
Se sintetizaron muestras de silicatos de calcio, a partir de diferentes concentraciones de tetraetilortosilicato (TEOS) y mediante la metodología Pechini, asistida con intercambio iónico a base de ...alginato de sodio y cloruro de calcio, seguido de un tratamiento térmico a 800°C por 2h. Las muestras A, B y C, que se obtuvieron utilizando 1,7×10−3M, 3,4×10−3M y 5,1×10−3M de TEOS, respectivamente, y sin tratamiento térmico, se caracterizaron por análisis termogravimétrico (TGA) y espectroscopia infrarroja con reflectancia total atenuada (FTIR-ATR). Por otra parte, las muestras A800, B800 y C800, que se obtuvieron usando un tratamiento térmico a 800°C por 2h, se caracterizaron por FTIR-ATR, área superficial específica por la técnica de adsorción de gas nitrógeno (BET), difracción de rayos X (DRX) y por microscopia electrónica de barrido. Por espectroscopia FTIR-ATR se confirmó la presencia de enlaces Si-O-Si, indicativos de la formación de silicatos y de sílice en las muestras A800, B800 y C800. Los difractogramas indican que la muestra A800 contiene olivino (Ca2SiO4) en fase ortorrómbica y wollastonite-2M (CaSiO3); la muestra B800 presentó, además de las fases anteriores, cuarzo (SiO2) en fase hexagonal, mientras que la muestra C800, obtenida con una mayor cantidad de TEOS, presentó las fases de wollastonita-2M y larnita (Ca2SiO4).
Calcium silicates samples were synthesized using tetraethyl orthosilicate (TEOS) and by Pechini methodology assisted with ion-exchange of sodium alginate, followed by a heat treatment of 800°C by two hours. A, B and C samples were obtained using 1.7×10−3M, 3.4×10−3M and 5.1×10−3M of TEOS, respectively, and without heat treatment; these samples were characterized by thermogravimetric analysis (TGA) and infrared spectroscopy with attenuated total reflectance (FTIR-ATR). Furthermore, samples A800, B800 and C800 obtained using a heat treatment of 800° by two hours were characterized by FTIR-ATR, absorption technique (BET), X-ray diffraction (XRD) and by scanning electron microscopy. The XRD patterns indicate that sample A800 contains olivine (Ca2SiO4) in orthorhombic phase and wollastonite-2M (CaSiO3); sample B800 showed the earlier phases and quartz (SiO2), whereas sample C800 contains wollastonite phases and larnite-2M (Ca2SiO4).
Maya nut (
) is a novel food with high nutritional value. This research aimed to evaluate the nutritional and antioxidant properties of Maya nut flour (MNF) made from seeds dried by different methods ...(sun-dried and using hot air at 45 °C and 60 °C) to explore its incorporation into cookies and evaluate its nutritional and functional properties. The naturally sun-dried flour (NF) had the highest content of ash (3.64 ± 0.11 g/100 g), protein (6.35 ± 0.44 g/100 g), crude fiber (6.75 ± 0.29 g/100 g), and functional properties (water and oil absorption). The color of the flour was affected by the different drying methods. While the drying methods influenced the total polyphenolic content (TPC) and antioxidant activity (AA) of MNF, they did not affect the morphology of the native starch or generated important molecular-structural changes. The substitution of 60% of wheat flour with NF in the cookie's formula increased the protein and fiber content, whereas 20% substitution increased its AA. MNF is a source of protein, dietary fiber, micronutrients, and functional compounds that can enrich cookie formulations.
Enzymatic saccharification of pretreated lignocellulosic biomass is a key step in the biochemical biorefineries. To be economically practical for large-scale use, the process must be run at high ...solids loadings, notably biomass concentrations of more than 15 % (w/v). However, as the solids loading increases, biomass develops a high-viscosity slurry that is severely mass transfer constrained and more difficult to mix, which restricts the addition of even more solids. Using a commercial enzyme mixture of cellulases and hemicellulases, high solid loading hydrolysis of hydrothermally and CO2-H2O pretreated agave bagasse was carried out in a continuous stirred tank bioreactor (CSTBR) and horizontal bioreactor (HB) to generate high glucose concentrations. With complete saccharification of 100 %, operation at the CSTBR at 20 % (w/v) solid loading yielded 119.9 g/L of glucose concentration, while operating at the HB at the same level of substrate loading was able to produce 134.4 g/L of glucose concentration. CO2-H2O pretreated biomass produced 123.6 g/L of glucose at the same loading on operation with a HB. The hydrolysis was greatly enhanced by the enzyme mixture. The current glucose conversion outcomes of hydrothermally processed biomass were unquestionably greater, with an energy efficiency 2.291 gsugar/MJ. The results of the present study conclusively show the concentration of glucose working at high solid loading by analyzing the energy consumption to improve the mechanical phenomenon at the stage of pretreatment hydrolysis. For the development of biorefineries, the design and development of this process will enable the establishment of ideal operating conditions and energy efficiency.
•Hydrothermal process produces a cellulose rich solid with high susceptibility to enzymatic hydrolysis.•CO2-H2O pretreatment is a promising process for biomass fractionation.•Horizontal bioreactors improve glucose production at high solid loadings.
The objective of this study was to evaluate the insecticidal activity of the polyphenolic compounds found in neem on S. frugiperda larvae. Three neem extracts (1:12 (m/v) with 70% ethanol, 1:12 (m/v) ...with 0% ethanol (only water), and 1:4 (m/v) with 0% ethanol) were employed. Subsequently, the extraction of phytochemical compounds of each extract was performed using ultrasound and microwave technologies simultaneously. The compound characterization was performed by HPLC-mass. In addition, the insecticidal evaluation of the neem extract was performed against S. frugiperda of the second-stage larvae. The extracts were applied by spraying the larvae according to each bioassay. Results showed that the extract obtained with a 1:12 (m/v) relationship and 70% ethanol was effective for the control of S. frugiperda larvae. In this extract, the predominant organic compound families were: methoxyflavones, flavonols, hydroxycoumarins, anthocyanins, methoxycinnamic acid, and alkylflavones. Phytochemical compounds obtained from neem seeds with environmentally friendly solvents and alternative technologies (ultrasound and microwave) have potent insecticidal activity against S. frugiperda larvae.
La presente recopilación bibliográfica muestra cómo son utilizados distintos nanomateriales para el tratamiento del cáncer por hipertermia, entre los cuales, los más empleados son los materiales que ...poseen propiedades magnéticas. Debido a su comportamiento superparamagnético, pueden ser expuestos a un campo magnético que a su vez produce un aumento de la temperatura hasta un máximo de 46 °C. Esta temperatura causa la eliminación de la mayoría de las células tumorales; este procedimiento se conoce como hipertermia magnética. El problema por resolver desde el punto de vista de la síntesis es encontrar un método simple que permita un control del tamaño de la partícula para obtener las propiedades de biocompatibilidad deseadas. Se concluye que la obtención de materiales para posibles aplicaciones de hipertermia se da por diversos métodos; entre los que destacan sol-gel, coprecipitación química, descomposición térmica, entre otros. Esta última es la mejor opción, ya que permite un mayor control del tamaño de la partícula. Además, es posible mejorar las propiedades de biocompatibilidad o magnéticas deseadas mediante recubrimientos superficiales o dopajes.
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