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Item type:Publication, Access status: with files , Properties of agar aerogels: effect of concentration and ageing time(Elsevier, 2026-06-01); ; ; ; Agar, a polysaccharide derived from red algae, is a renewable, edible, and biocompatible hydrocolloid with excellent gelling properties. Although widely used in the food industry and microbiology, its potential for advanced material design, particularly as an aerogel, has not yet been sufficiently explored. In this study, agar aerogels were produced via the sol-gel process and supercritical CO2 drying. The effects of polysaccharide concentration (2%, 6%, and 10% w/v) and ageing time (24 h and 10 days) on the structural, textural and compressive mechanical properties were systematically investigated for the first time. All aerogels were highly porous, with specific surface areas reaching a maximum of 375 m2/g at a moderate agar concentration (6% w/v). Prolonged ageing generally improved the textural and morphological properties but reduced the compression strength and swelling capacity. All samples showed excellent water uptake and remained stable in aqueous environments for four weeks. These results demonstrate that both concentration and ageing time significantly affect the final performance of the agar aerogels. Their properties can be easily adjusted by processing parameters, offering great potential for biomedical, food-related, or environmental applications.Publicationtype: Journal Article28 42 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Starch aerogels as nutraceutical carriers: Experimental and computational strategies for designing a delivery systemThe exceptional properties of aerogels explain their growing applicability in different research areas. In the case of nutraceutical delivery, they hold the potential to improve the common challenges of poor bioavailability and low stability of the bioactive ingredients, thereby enhancing intestinal delivery. Starch aerogels offer additional attractive features: biocompatibility, potential cost reduction, and abundance of raw materials. This review explores the development of starch aerogels as carriers for nutraceutical delivery, and how it can be rationalized with molecular simulation. The fundamentals of starch aerogels and the existing literature on the carriers are explored, including synthesis procedure, morphology, nutraceutical loading, and characterization of the resulting delivery system. Molecular simulation is identified as a key tool for examining properties and interactions occurring at the nano- and sub-nanoscale. The current gaps in the field are critically discussed, and trending topics for future research are identified. A computational-assisted design combined with a systematic approach to production routes is needed to further develop the field of starch aerogels for nutraceutical delivery, in addition to assessing toxicity, stability during storage, and scale-up viability.Publicationtype: Review Article40 24 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Pectin-based aerogel particles for drug delivery: Effect of pectin composition on aerogel structure and release properties(Elsevier, 2023-01-21); ; ; ; In this work, nanostructured pectin aerogels were prepared via a sol-gel process and subsequent drying under supercritical conditions. To this end, three commercially available citrus pectins and an in-house produced and enzymatically modified watermelon rind pectin (WRP) were compared. Then, the effect of pectin's structure and composition on the aerogel properties were analysed and its potential application as a delivery system was explored by impregnating them with vanillin. Results showed that the molecular weight, degree of esterification and branching degree of the pectin samples played a main role in the production of hydrogels and subsequent aerogels. The developed aerogel particles showed high specific surface areas (468–584 m2/g) and low bulk density (0.025–0.10 g/cm3). The shrinkage effect during aerogel formation was significantly affected by the pectin concentration and structure, while vanillin loading in aerogels and its release profile was also seen to be influenced by the affinity between pectin and vanillin. Furthermore, the results highlight the interest of WRP as a carrier of active compounds which might have potential application in food and biomedical areas, among others.Publicationtype: Journal ArticleScopus© Citations 19 86 414 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Pectin-based nanocomposite aerogels for potential insulated food packaging applicationEnvironmental-friendly pectin-TiO2 nanocomposite aerogels were prepared via sol-gel process and subsequent drying under supercritical conditions. The first step includes dissolution of pectin in water, addition of proper amount of TiO2 colloid and crosslinking reaction induced in the presence of tert-butanol and zinc ions. Then, the gels are subjected to the solvent exchange and supercritical CO2 drying. The influence of TiO2 nanoparticles on the textural, mechanical, thermal and antibacterial properties of aerogels was investigated. Results indicate that in the presence of TiO2 nanoparticles (NPs) mechanical, thermal and antimicrobial properties of pectin-based aerogels are improved in comparison to the control pectin aerogels. It should be emphasized that the thermal conductivity of pectin-based aerogels (0.022-0.025 W m-1 K-1) is lower than the thermal conductivity of air. Generally, the results propose that the pectin-TiO2 nanocomposite aerogels, as bio-based material, might have potential application for the storage of temperature-sensitive food.Publicationtype: Journal Article194 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , A redox strategy to tailor the release properties of Fe(III)-alginate aerogels for oral drug delivery(2018-05-15); ; ; ; Iron(III)-crosslinked alginate aerogel beads (d = 3-5 mm) were prepared and loaded with ibuprofen by using the technique of adsorptive deposition from supercritical CO2. Additional formulations were prepared where the aerogels were co-impregnated by ibuprofen and ascorbic acid. The release of ibuprofen from the Fe(III)-alginate is much faster in pH = 7.4 (PBS) than in pH = 2.0 (HCl), which can be explained by the faster dissolution and higher swelling of the alginate matrix in PBS. By decreasing the size of the beads and using a higher G content alginate the release rate could be slightly increased. A marked acceleration of drug release was achieved in both HCl and PBS by incorporating ascorbic acid into the Fe(III)-alginate aerogel preparations. The explanation is that in aqueous media ascorbic acid in situ reduces the crosslinking Fe(III) to Fe(II). The latter does not interact strongly with alginate, which promotes the hydration of the chains, thus the erosion and dissolution of the carrier matrix.Publicationtype: Journal Article140 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , An injectable alginate-based hydrogel for microfluidic applications(Elsevier, 2017-01-09); ; ; ; The objective of this study was to develop an injectable alginate based formulation for immobilizing enzymes into microfluidic systems. The gelation was induced upon lowering the pH by addition of D-glucono-δ-lactone (GDL) and release of Ca+ ions from solid CaCO3. The effects of GDL concentration on enzymatic activity and gelation time were investigated. The results indicated that increasing the GDL concentration increased both surface area and enzymatic activity. Also, chitosan was added to the formulation at different ratios to enhance the stability of enzyme during immobilization. For microfluidic application, 100 μl spiral coil single channel microchip was fabricated and alginate GDL mixture containing β-glucosidase was injected to the microchannel prior to gelation. Enzymatic conversion was performed by pumping substrate (pNPG) through the microchannel. The results indicated that the entire substrate was converted continuously during 24 h without any leakage or deactivation of immobilized enzyme.Publicationtype: Journal Article155 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Polysaccharide-based aerogel microspheres for oral drug delivery(Elsevier, 2014-10-13); ; ; ; Polysaccharide-based aerogels in the form of microspheres were investigated as carriers of poorly water soluble drugs for oral administration. These bio-based carriers may combine the biocompatibility of polysaccharides and the enhanced drug loading capacity of dry aerogels. Aerogel microspheres from starch, pectin and alginate were loaded with ketoprofen (anti-inflammatory drug) and benzoic acid (used in the management of urea cycle disorders) via supercritical CO2-assisted adsorption. Amount of drug loaded depended on the aerogel matrix structure and composition and reached values up to 1.0 × 10-3 and 1.7 × 10-3 g/m2 for ketoprofen and benzoic acid in starch microspheres. After impregnation, drugs were in the amorphous state in the aerogel microspheres. Release behavior was evaluated in different pH media (pH 1.2 and 6.8). Controlled drug release from pectin and alginate aerogel microspheres fitted Gallagher-Corrigan release model (R2 > 0.99 in both cases), with different relative contribution of erosion and diffusion mechanisms depending on the matrix composition. Release from starch aerogel microspheres was driven by dissolution, fitting the first-order kinetics due to the rigid starch aerogel structure, and showed different release rate constant (k1) depending on the drug (0.075 and 0.160 min-1 for ketoprofen and benzoic acid, respectively). Overall, the results point out the possibilities of tuning drug loading and release by carefully choosing the polysaccharide used to prepare the aerogels.Publicationtype: Journal Article65 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Preparation of tailor-made starch-based aerogel microspheres by the emulsion-gelation methodThe inherent biocompatibility and biodegradability of starch, a natural polysaccharide-based product, allows its use in the form of microspheres as a chemical carrier for life science applications. However, current methods of preparation of starch microspheres utilize chemical crosslinkers and drying methods (air drying, freeze drying) that leads to problems of degradability of the matrix and low specific surface areas and chemical loading capacities. In this work, corn starch aerogel microspheres, a special class of nanoporous materials, were prepared by the combination of an emulsion-gelation method and supercritical drying without the use of chemical crosslinkers. Effects of gelation temperature (368, 393 and 413 K), oil-to-aqueous starch solution ratio (1:1, 2:1, 3:1) and surfactant content (3, 6 and 10% (w/w)) on the textural and morphological properties of the aerogel material were studied. The obtained starch aerogels were characterized using nitrogen adsorption-desorption measurements, helium pycnometry, CHN elemental analyses, thermogravimetry and scanning electron microscopy. Spherical starch aerogel microspheres with tailor-made specific surface areas (34-120 m 2 g -1 range) and particle sizes (215-1226 μm diameter range) were obtained. Aerogel textural properties were mainly influenced by the gelation temperature used, whereas the particle morphology depended on the three processing parameters studied. High specific chemical loading capacity (1.1 × 10 -3 g m -2) of the aerogel microspheres was obtained using ketoprofen as a model compound.Publicationtype: Journal Article24 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Polysaccharide-based aerogels - Promising biodegradable carriers for drug delivery systemsPolysaccharides are regarded as key ingredients for the production of bio-based materials in life sciences (e.g., food, cosmetics, medical devices, pharmaceutics). The biodegradability and biocompatibility of these biopolymers, coupled to the large variety of chemical functionalities they encompass, make them promising carriers for drug delivery systems. Aerogels are a special class of nanoporous materials with growing interest in biomedical and pharmaceutical applications due to their open pore structure and high surface area. Polysaccharide-based aerogels result in highly porous (ε = 90-99%), lightweight (ρ = 0.07-0.46 g/cm3) drug carriers with high surface area (Sa = 70-680 m2/g), able to provide enhanced drug bioavailability and drug loading capacity. This review focuses on the state-of-the-art of the production of polysaccharide-based aerogels with emphasis on the influence of processing parameters on the resulting end material properties. Case studies on polysaccharide-based aerogels from several sources and own results as well as their behavior regarding drug loading capacity and release are described.Publicationtype: Journal Article46 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Dynamic rheological and physicochemical properties of annealed starches from two cultivars of cassavaStarch from tubers of "sweet" (low cyanide) and "bitter" (high cyanide) cassava (Manihot esculentum Crantz) crops was isolated and subjected to annealing treatment at 50 °C for 24,96,144 and 192 h in 1:5 starch to water ratio. Annealing generally reduced the swelling power and solubility of the starches. Storage modulus (G′) and loss modulus (G″) increased with decrease in complex viscosity (Eta*) as a function of angular frequency (ω). The magnitudes of G′ reported were greater than those of G″ revealing frequency dependency except sweet starch cultivar annealed at 192 h. The tan δ (ratio of G″/G′) of annealed starches were within the ranges of 0.31-0.39 and 0.23-0.45 for sweet and bitter cultivars, respectively. The tan δ values of the starches were lower than one, indicating that the samples are elastic in nature than viscous. The X-ray patterns of the A-type starches were not altered on annealing denoting that the double helices in the amorphous region were not disrupted. Annealing as revealed by scanning electron micrographs changed the structure of the sweet cultivar, while there was no change in the size and shape of the bitter cultivar.Publicationtype: Journal Article10