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Item type:Publication, Access status: without files , Tailoring polysaccharide-based aerogels for potential food applications: Structural and hydration characterization by NMR relaxometry and diffusometryPolysaccharide-based aerogels are promising candidates for food-related applications due to their high surface area, adjustable porosity, biocompatibility, and biodegradability. The present study investigated chitosan, sodium alginate, and xanthan gum aerogels obtained by supercritical CO2 drying. Each polysaccharide exhibited unique structural and physicochemical behavior depending on polymer concentration, which influenced the final aerogel properties such as bulk density, pore size, surface area, and water absorption. NMR relaxometry and diffusometry were employed for a detailed characterization of pore structure, hydration behavior, and molecular mobility. Results revealed that, in contrast to alginate aerogels, lower polymer concentrations in chitosan led to more open networks with larger pores and higher surface areas, making them more suitable for applications such as filtration, adsorption, or active compound delivery. On the other hand, xanthan gum aerogels formed denser, more crosslinked structures, yielding high water absorption rate suitable for controlled release or encapsulation purposes. A hybrid chitosan/alginate aerogel successfully combined the advantageous properties of both components, resulting in low-density materials with enhanced porosity and mechanical integrity. The difference in aerogel structures obtained by different polysaccharides highlights the possibility of tailoring aerogel properties for specific food applications, from active packaging to edible carriers or moisture regulators. Given the need for safer, biodegradable, and versatile materials in the food industry, this study highlights the importance of designing aerogels based on the material type and offers a practical guide for producing them using scalable and safe methods.Publicationtype: Journal Article55 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , In vivo tests of a novel wound dressing based on agar aerogelAerogels, especially bio-based ones, present a promising option for wound dressing; specifically, because of their low toxicity, high stability, bio-compatibility, and good biological performance. In this study, agar aerogel was prepared and evaluated as novel wound dressing material in an in vivo rat study. Agar hydrogel was prepared by thermal gelation, after that the water inside the gel was exchanged with ethanol, and finally the alcogel was dried by supercritical CO2. The textural and rheological properties of the prepared aerogel were characterized, showing that the prepared agar aerogels possess high porosity (97–98 %), high surface area (250–330 m2g−1) as well as good mechanical properties and easiness of removal from the wound site. The results of the in vivo experiments macroscopically demonstrate the tissue compatibility of the aerogels in dorsal interscapular injured rat tissue and a shorter wound healing time comparable to that of gauze-treated animals. The histological analysis underpins the reorganisation and healing of the tissue for the injured skin of rats treated with agar aerogel wound dressing within the studied time frame.Publicationtype: Journal ArticleScopus© Citations 6 53 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Application of Aquasolv Lignin in ibuprofen-loaded pharmaceutical formulations obtained via direct compression and wet granulationAS (Aquasolv) Lignin produced via Liquid Hot Water Pretreatment and Enzymatic Hydrolysis has shown potential as an active pharmaceutical ingredient and/or excipient in solid dosage forms. Moreover, lignin is safe to consume and presents antioxidant and antidiabetic capacity, properties that can add to solid dosage forms in pharmaceuticals. This work aimed to evaluate the performance of tablets produced via direct compression and wet granulation when lignin is used in combination with commercial excipients. In order to find optimal tablet performance, different lignin formulations were assessed, and the concentrations were given by extreme vertices mixture design (13 formulations). The blends were composed of AS Lignin, Microcrystalline Cellulose, and Lactose monohydrate and the optimized blend was found to be 14.53 w/w% of disintegrant, 26.57 w/w% of binder and 58.9 w/w% of AS lignin. This proportion was further used to evaluate the performance of lignin-based tablets in drug release, using Ibuprofen as a drug model (50 w/w% and 70 w/w%) and for comparison of direct compression with wet granulation. Direct compressed tablets resulted in higher drug dissolution rates when compared with wet granulation, nevertheless; both tableting techniques showed promising results for lignin. More than 5 formulations tested in this work are compliant with International Pharmacopoeia regulations for solid dosage pharmaceutical forms, thus AS Lignin shows potential to be used as an excipient in pharmaceutical formulations. Industrial relevance: Industrially, AS Lignin appears as promising excipient in the pharmaceutical technologies as well as boost in the biorefining technologies in the following years. Lignin produced is free of sulfur, can be labelled as clean and environmentally-friendly and in this study, was proven this non-cytotoxic AS lignin can be used for excipients and drug carriers. The findings in this paper showed the use of product formulation for life science purposes, thus stressing one of possibilities for lignin valorization in biorefineries.Publicationtype: Journal ArticleScopus© Citations 16 85 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Novel alginate-chitosan aerogel fibres for potential wound healing applicationsAerogels produced from marine polymers, such as chitosan and alginate, are of interest for wound healing applications due to their attractive properties. These properties can be the aerogel's high porosity along with the antimicrobial activity of chitosan or the capacity to provide a moist environment of alginate. The aim of this work was to develop a new route towards hybrid alginate-chitosan aerogel fibres and to evaluate their potential for wound healing applications. The influence of chitosan molecular weight and its content on the fibres characteristics was evaluated. To produce the fibres, the formation of polyelectrolyte complex hydrogels of both polymers was performed by the emulsion-gelation method. Hydrogels were converted in alcogels through a solvent exchange followed by drying with supercritical CO2. Resulting aerogels were observed to be light-weight, fluffy mesoporous fibres with a specific surface area of 162–302 m2/g and specific pore volume of 1.41–2.49 cm3/g. Biocompatibility of the fibres was evaluated, and the result showed that they were non-cytotoxic. Bioactivity of the fibres regarding the ability to close a wound on an in vitro scale and antibacterial activity were also evaluated. Aerogel fibres presented percentages of recovered scratch area of about 75%, higher than the untreated control (~50%) and a clear antibacterial activity against Staphylococcus aureus and Klebsiella pneumoniae. The obtained results suggest that these alginate-chitosan aerogel fibres could be good candidates for wound healing applications.Publicationtype: Journal Article88 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Impregnation of passion fruit bagasse extract in alginate aerogel microparticles(Elsevier, 2020-07-15); ; ; ; Passion fruit bagasse extract (PFBE) is a rich source of polyphenols, including piceatannol. This work produced alginate (1, 2, 3 wt%) aerogel and investigated the impregnation of gallic acid (GA) and PFBE in alginate aerogel microparticles. The microparticles of ca. 100 μm in diameter were obtained by emulsion-gelation method, submitted to solvent exchange, wet impregnation (WI) and supercritical drying. Alginate aerogels derived from 1 wt% solution led to a higher GA loading and, therefore, this formulation was used to impregnate PFBE. The loading of PFBE, total phenolic, and piceatannol contents based on grams of raw aerogel were 0.62 g, 10.77 mg, and 741.85 μg, respectively, which means a loading efficiency of total phenolics and piceatannol of 47.1% and 34.7%. DSC analysis and X-ray diffraction showed that particles behave as amorphous materials and ORAC assay revealed that impregnated aerogel microparticles presented antioxidant capacity. Alginate aerogel microparticles presented as an appropriated material for drug loading, whereas WI and supercritical drying demonstrated to be useful techniques to load PBBE in aerogels.Publicationtype: Journal Article175 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Cytotoxicity and biological capacity of sulfur-free lignins obtained in novel biorefining processLignin is one of the most promising and versatile products obtained in biorefineries due to its diverse therapeutic properties such as antimicrobial, antioxidant and anti-inflammatory activity. However, these properties depend on the source of lignin and the way it was isolated from the biomass. In this study, four different lignins are compared (extracted with Aquasolv (ASL1, ASL2), Organosolv (OSL) and Alkali (ALK) processes) for their cellular antioxidant capacity, anti-diabetic activity, free radical scavenging and cytotoxicity. Alkali and Organosolv lignins showed the highest antioxidant capacity 1159.815 μmol TE g−1 and 1463.415 μmol TE g−1, respectively, in agreement with their highest amount of free –OH groups. Additionally, OSL showed the highest inhibition in the antidiabetic assay followed by ASL1 with values for α–amylase of 3.6 mg/ml and 4.3 mg/ml respectively, and α–glucosidase 1.6 mg/ml and 2.5 mg/ml correspondingly. Nevertheless, cell-based assays revealed that ASL has the lowest cytotoxic effect in Caco-2 cells and, thus, is 10 times less cytotoxic than Alkali and OSL. This work suggests the applicability of ASL for high value applications such as cosmetics or pharmaceuticals. Industrial relevance: Industrially, Liquid Hot Water (LHW) and Organosolv processes may appear as promising biorefining technologies in the following years. Lignin produced is free of sulfur, can be labelled as clean and environmentally-friendly and in this study, was proven that LHW lignin is non cytotoxic. The findings in this paper showed that different sources of lignin can be used in product formulation for life science purposes, thus opening a broad spectrum of possibilities for lignin valorisation in biorefineries.Publicationtype: Journal Article212