Browsing by Author "Costa, Joana R."
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- Delivery systems for antimicrobial peptides and proteins: towards optimization of bioavailability and targetingPublication . Costa, Joana R.; Sarmento, Bruno; Silva, Nádia C.; Pintado, ManuelaAntimicrobial peptides (AMPs) and proteins are produced by a wide range of organisms as important elements of their defense mechanisms, forming a large number of antimicrobial compounds that can be used to treat several human infections. The potential for the use of AMPs and antimicrobial proteins in therapeutics is growing, but their application is often limited, due to their poor physical and/or chemical properties. In recent years, several drug delivery systems have been proposed to carry such molecules, in an attempt to overcome the difficulties regarding their properties. However, no review has yet systematized the most relevant information on this subject. Therefore, this review summarizes the work that has been conducted to develop delivery systems for the transport and protection of AMPs and antimicrobial proteins, including their description and potential applications, while highlighting the opportunities for future research in this field.
- Enzymatic production of xylooligosaccharides from Brazilian Syrah grape pomace flour: a green alternative to conventional methods for adding value to agricultural by-productsPublication . Costa, Joana R.; Tonon, Renata V.; Gottschalk, Leda M. F.; Santiago, Manuela C. P. A.; Mellinger-Silva, Caroline; Pastrana, Lorenzo; Pintado, Maria M; Cabral, Lourdes M. C.BACKGROUND: The aim of this work was to determine the most favorable conditions for the production of xylooligosaccharides (XOS) from Brazilian Syrah grape pomace. Chemical processes were performed using a rotatable central composite design, where the concentration of sulfuric acid or concentration of sodium hydroxide and grape pomace flour: solvent mass ratio were the dependent variables. Enzymatic production was also evaluated using xylanase produced by Aspergillus niger 3T5B8 and Viscozyme® enzymatic commercial cocktail. RESULTS: Chemical extraction allowed to recover 21.8 to 74.6% and 5.2 to 96.3% of total XOS for acid and alkaline processes, respectively. Enzymatic production using xylanase extracted up to 88.68 ± 0.12% of total XOS and up to 84.09 ± 2.40% with Viscozyme®. CONCLUSION: The present study demonstrated different feasible methods to produce high added value molecules, the xylooligosaccharides, from Syrah grape pomace flour, valorizing this major by‐product. The use of enzymatic cocktails demonstrated to be an alternative to the conventional methods, allowing to obtain an eco‐friendly and sustainable grape pomace extract.
- Fire-resistant bio-based polyurethane foams designed with two by-products derived from sugarcane fermentation processPublication . Capêto, Ana Paula; Amorim, Manuela; Sousa, Sérgio; Costa, Joana R.; Uribe, Braian; Guimarães, Ana Sofia; Pintado, Manuela; Oliveira, Ana L. S.There is a growing interest in replacing conventional fossil-based polymers and composites with waste-based materials and fillers for environmental sustainability. This study designed water-blown polyurethane rigid foams using two by-products from the Amyris fermentation process of producing β-farnesene. The distillation residue (FDR) served as the main polyol component in the foam’s formulation (PF), supplemented with 4.5% sugarcane bagasse ash (SCBA) as a fire-retardant filler (PFA). The study assessed the impact on foam properties. Based on the analysis of all compiled data (foam structure, mechanical, and thermal properties), it can be inferred that ash particles acted as nucleating points in the reaction media, leading to a reduction in foam density (from 134 to 105 kg/m3), cell size (from 496 to 480 nm), and thermal conductivity. The absence of chemical interaction between the ash filler and the polyurethane matrix indicates that the ash acts as a filler with a plasticizing effect, enhancing the polymer chain mobility. As a result, the glass transition temperature of the foam decreases (from 74 to 71.8 ºC), and the decomposition onset temperature is delayed. Although, the incorporation of 4.5% SCBA (grain size below 250 μm) was ineffective in the increment of the compressive strength, that small amount was enough to increase the foam’s specific strength from 1009 to 1149 m2/s2 suggesting that other factors (e.g. polyol feedstock, grain size, ash packing, etc.) are yet to be accounted. The flammability test results indicate that sugarcane bagasse ash improved the foam performance, reducing burning time from 251 to 90 s, time of extinguishment from 255 to 116 s, and burning length from 132 to 56.7 mm, meeting the fire protection standard UL 94, class HB. Despite the need for further improvement and detailed flammability evaluation, the results support the notion that polyurethane foams from renewable waste by-products offer a sustainable alternative to both edible and fossil-based sources. Additionally, sugarcane bagasse ash can be a suitable silica source for reinforcing composites with reduced flammability, potentially replacing harmful halogenated chemicals used for the same purpose.
- Fortification of coconut water with microencapsulated grape pomace extract towards a novel electrolyte beverage: biological, sensorial and quality aspectsPublication . Costa, Joana R.; Monteiro, Maria João; Tonon, Renata V.; Cabral, Lourdes M.C.; Pastrana, Lorenzo; Pintado, Manuela E.A bioactive grape pomace extract (GPE) rich in polyphenols was encapsulated into alginate (GPE-Alg) or chitosan (GPE-CS) microparticles, later incorporated into coconut water. Biological and sensory properties were evaluated. Storage was performed at 4 ˚C followed by quality assessment. Evaluation of coconut water after gastrointestinal digestion on the growth pathogens and probiotic bacteria showed that the fortification with GPE-Alg and GPE-CS decreased the growth rate of pathogens when compared to non-fortified water, while promoted the growth of different bifidobacteria and lactobacilli strains. Sensory analysis allowed to conclude that the incorporation of GPE-Alg and GPE-CS did not promote significant differences in most of evaluated attributes, including aroma and flavor. The storage at 4 ˚C allowed a reduced degradation rate of total phenolics and anthocyanins for GPE-Alg and GPE-CS fortified beverage, with the half-life time of phenolic acids higher for GPE-Alg beverage and the half-life time of anthocyanins higher for GPE-CS fortified water. This study opens the opportunity in the application of food by-products in the development of novel efficient functional foods and beverages.
- Impact of in vitro gastrointestinal digestion on the chemical composition, bioactive properties, and cytotoxicity of Vitis vinifera L. cv. Syrah grape pomace extractPublication . Costa, Joana R.; Amorim, Manuela; Vilas-Boas, Ana; Tonon, Renata V.; Cabral, Lourdes M. C.; Pastrana, Lorenzo; Pintado, ManuelaGrape pomace (GP) is a major byproduct worldwide, and it is well known for its bioactive compounds, such as fibers and phenolic compounds, that are popular for their impact upon human health, including gastrointestinal health. The objective of this work was to evaluate the chemical composition and biological activities of an enzymatic GP extract, as well as to investigate how gastrointestinal digestion (GID) modulates these properties. GP extract was previously produced using an enzymatic cocktail with xylanase activity and was then exposed to simulated conditions of GID, characterized for its chemical composition, and screened for antimicrobial, prebiotic, and antioxidant activities. The safety of this ingredient after GID was also assessed. GP extract presented high contents of dietary fiber and other carbohydrates, including xylooligosaccharides, in addition to minerals and phenolic compounds. In vitro simulated GID revealed that xylobiose was resistant to gastric conditions, unlike phenolic compounds. The use of 2% (w/v) of this ingredient proved to be a potential carbon source that could be fermented by Lactobacillus and Bifidobacterium spp, even after digestion. The extract also exhibited strong antioxidant and antimicrobial activities against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa; however, after GID, the antioxidant capacity decreased, and the antimicrobial capacity was strongly reduced or lost. Furthermore, the extract safety was also guaranteed on Caco-2 intestinal cells. This novel and green GP extract proved to be composed of relevant bioactive molecules, including xylooligosaccharides, polyphenols, organic acids, and minerals, which provided different biological properties; it has potential applications in the food industry such that it can be used as an ingredient in the development of new functional foods.
- Polymeric nanoparticles as oral delivery systems for a grape pomace extract towards the improvement of biological activitiesPublication . Costa, Joana R.; Xavier, Miguel; Amado, Isabel R.; Gonçalves, Catarina; Castro, Pedro M.; Tonon, Renata V.; Cabral, Lourdes M.C.; Pastrana, Lorenzo; Pintado, Manuela E.Grape pomace (GP) is a major by-product from the wine industry, known for its bioactive compounds and their impact upon gastrointestinal (GI) health. However, bioaccessibility is often poor due to their degradation during digestion. This work aimed to encapsulate bioactive GP extract (GPE) into chitosan (CS) and alginate (Alg) nanoparticles (NPs) to mitigate degradation in the GI tract. Alg and CS NPs were optimized using a rotatable central composite design and NPs were characterized for their size, polydispersity, zeta potential and total phenolics (TP) association efficiency. The best formulations showed sizes ranging 523–853 nm, polydispersity indexes of 0.11–0.36, zeta potential of −15.0–14.9 mV and TP association efficiencies of 68 and 65%. FTIR confirmed that there was no formation of new chemical groups after association of the polymers with GPE. Both formulations improved the bioaccessibility of different phenolics following in vitro GI digestion, leading to in-creased antioxidant and antimicrobial activities. Moreover, the permeability of bioactive compounds through a Caco-2/HT29-MTX co-culture was reduced, suggesting a higher residence time in the intestine. Cy5.5 was used for tracking the CS NPs, which did not affect the metabolic activity of Caco-2 and HT29-MTX cells. Confocal microscopy images confirmed the adsorption of NPs to the cellular layer and suggested a reduction of the tight junction protein occludin when cells were incubated with Cy5.5-CS in solution. This study suggests that encapsulation of GPE can offer protection against along the GI tract and improve its biological activity with significant impact for oral delivery applications, including functional foods.
- Porphyridium cruentum: a factory for the production of a new polysaccharide-based biomaterial for tissue regenerationPublication . Duarte, Marta M.; Suprinovych, Artem; Silva, Inês V.; Ramos, Oscar L.; Costa, Joana R.; Rojo, Luis; Oliveira, Ana L.Marine algae and their metabolites have been widely recognized for their bioactive properties with applications in various industries, such as nutraceutical, cosmetical, and pharmaceutical. In this study, the best strategy for the extraction and processing of the exopolysaccharides (EPS) from Poryphydium cruentum for a laboratory scale was discussed, and the collected, purified EPS fraction was extensively characterized. The results show that impurities and other co-precipitants can be significantly reduced via trichloroacetic acid (TCA) treatment, followed by dialysis, resulting in a more purified EPS fraction with a higher carbohydrate content and solubility ability, at the cost of lower mass yield. The obtained EPS fraction was of a high molecular weight, presented a high crystallinity index, was thermally stable and cytocompatible within the range of tested concentrations. These results show its potential to be used as a new platform for healing and regeneration of chronic wounds.
- Silica microparticles from sugarcane by-products as an encapsulation system for retinoids aimed at topical sustained releasePublication . Costa, Joana R.; Costa, Ana Helena; Azevedo-Silva, João; Tavares-Valente, Diana; Sousa, Sérgio C.; Neto, Tânia; Pintado, Manuela E.; Madureira, Ana RaquelThe encapsulation of retinol within silica microparticles has emerged as a promising opportunity in the realm of cosmetic and pharmaceutical formulations, driven by the need to reinforce the photoprotection and oxidation stability of retinol. This work examines the process of encapsulating retinol into silica microparticles. The association efficiency, microparticle size, molecular structure, morphology, oxidation, and release profile, as well as biocompatibility and skin sensitization, were evaluated. Results showed that 0.03% of retinol and 9% of emulsifier leads to an association efficiency higher than 99% and a particle size with an average of 5.2 µm. FTIR results indicate that there is an association of retinol with the silica microparticles, and some may be on the surface. Microscopy indicates that when association happens, there is less aggregation of the particles. Oxidation occurs in two different phases, the first related to the retinol on the surface and the second to the associated retinol. In addition, a burst release of up to 3 h (30% free retinol, 17% associated retinol) was observed, as well as a sustained release of 44% of retinol up to 24 h. Encapsulation allowed an increase in the minimal skin cytotoxic concentrations of retinol from 0.04 μg/mL to 1.25 mg/mL without skin sensitization. Overall, retinol is protected when associated with silica microparticles, being safe to use in cosmetics and dermatology.
- Sugarcane straw as a source of arabinoxylans: optimization and economic viability of a two-step alkaline extractionPublication . Costa, Joana R.; Pereira, Maria J.; Pedrosa, Sílvia S.; Gullón, Beatriz; Carvalho, Nelson M. de; Pintado, Manuela E.; Madureira, Ana RaquelSugarcane processing produces a significant amount of byproducts in the form of straw and bagasse, which are rich in cellulose, hemicellulose, and lignin. This work aims to provide a valorization approach to sugarcane straw by optimizing a two-step alkaline extraction of arabinoxylans by a response surface methodology to evaluate a potential industrial-scale production. Sugarcane straws were delignified using an alkaline–sulfite pretreatment, followed by alkaline extraction and precipitation of arabinoxylan, a two-step process optimized using a response surface methodology. A KOH concentration of (2.93–17.1%) and temperature (18.8–61.2 °C) were chosen as independent variables, and the arabinoxylan yield (%) as a response variable. The model application shows that KOH concentration, temperature, and the interaction between both independent variables are significant in extracting arabinoxylans from straw. The best-performing condition was further characterized by FTIR, DSC, and chemical and molecular weight evaluation. The straws arabinoxylans presented high purities levels, ca. 69.93%, and an average molecular weight of 231 kDa. The overall estimated production cost of arabinoxylan from straw was 0.239 €/g arabinoxylan. This work demonstrates a two-step alkaline extraction of the arabinoxylans method, as well as their chemical characterization and economic viability analysis, that can be used as a model for industrial scale-up production.
- Sugarcane straw hemicellulose extraction by autohydrolysis for cosmetic applicationsPublication . Pereira, Maria João; Pedrosa, Sílvia S.; Costa, Joana R.; Carvalho, Maria João; Neto, Tânia; Oliveira, Ana L.; Pintado, Manuela; Madureira, Ana RaquelSugarcane is a popular crop whose cultivation generates a wide range of by-products. The aim was to optimize the hydrothermal extraction of hemicellulose from sugarcane straw using response-surface methods with a two-factor composite design and to assess its functional qualities. Three process parameters were subject to optimization: solid/liquid ratio (1:6–1:18), temperature (143–186 °C), and extraction time (20–60 min). A xylooligosaccharide (XOS)-enriched extract was characterized regarding its chemical composition, molecular weight, and antioxidant and antimicrobial potential. The optimized extraction yield was 24.46 g/100 g of straw with a polymerization degree of 17.40. Both hemicellulose and XOS demonstrated notable antioxidant properties, with antioxidant effects of 73% and 85%, respectively. Regarding skin enzyme activity, hemicellulose inhibited elastase by more than 50%, while XOS showed no significant effect. However, both extracts exhibited collagenase (MMP1) inhibition comparable to the positive control. In terms of production feasibility, the estimated costs were 130.5 EUR/kg for hemicellulose and 272.5 EUR/kg for XOS. Overall, the optimized XOS-enriched sugarcane straw extract demonstrated promising anti-aging, antioxidant, and preservative properties, highlighting its potential for cosmetic applications.