Publications

Abstract The excessive use of biocides has considerable environmental and economic impacts; this is why new technologies have been sought to decrease the concentration levels applied in an effort to reduce the use of these substances. Microencapsulation using cyclodextrins has been widely used in the food and pharmaceutical industries as a way of reducing the concentrations of the active substance necessary to achieve a biological effect and/or eliminate its irritating or toxicological effects. In this study, the inclusion complexation behavior and binding ability of benzothiazolinone (BIT) with different beta-cyclodextrins (beta-CD, HP-beta-CD, and Me-beta-CD) was investigated. The intermolecular interactions were examined through UV and FTIR spectroscopy, DSC, 1D 1H NMR, and 2D ROESY. The highest stability constant was observed for the BIT/Me-beta-CD inclusion complex (299.5 +/- 2.9 M-1). Antibacterial activity was investigated against Staphylococcus aureus and Escherichia coli, and the results revealed that the BIT/Me-beta-CD inclusion complex displays a higher antibacterial activity than BIT. The acute toxicity of the biocide and inclusion complex was also examined using the photobacterium Aliivibrio fischeri. Although BIT exhibited higher toxicity than the inclusion complex, further investigation is needed due to the quorum quenching effect of beta-CDs. The data found suggest that BIT microencapsulation can increase its aqueous solubility and can be used as an effective tool to improve its chemical, biological, and ecotoxicological properties.

Abstract Soybean is a legume with high technological functionality, commonly used by the food industry as an ingredient in different products. However, soybean is an allergenic food whose undeclared presence in processed foods may represent a public health risk. In this work, it was developed an efficient electrochemical immunosensor, targeting the soybean trypsin inhibitor (Gly m TI) allergen using commercial anti-Gly m TI IgG, aiming at detecting/quantifying minute amounts of soybean in different food formulations. For this purpose, model mixtures of different foods (sausages, cooked-hams, biscuits) were prepared to contain known amounts of soybean protein isolate (100,000-0.1 mg kg(-1)) and submitted to specific thermal treatments (autoclaving, oven-cooking, baking). The electrochemical immunosensor allowed quantifying down to 0.1 mg kg(-1) of soybean in the three food matrices, raw and processed (0.0012 mg of Gly m TI/kg of matrix). Accordingly, the immunosensor is suitable for detecting traces of soybean in raw, processed, and complex foods, thus protecting 99 % of soybean-allergic patients.

Abstract Catechol-O-methyltransferase inhibitors (iCOMT), such as entacapone, have been successfully employed to treat tremor-related symptoms of Parkinson's disease. However, iCOMT has been associated with a short half-life and poor oral bioavailability. Nanobased drug delivery systems have often been used to overcome this type of setbacks. Therefore, entacapone was encapsulated in PEGylated poly(lactic-co-glycolic acid) (PLGA)-based nanoparticles (NPs) via a nanoprecipitation process, as well as in PEGylated nanostructured lipid carriers (NLCs) using a solvent emulsification/evaporation method. Both nanoformulations presented sub-200 nm populations, with zeta-potential (ZP) values close to -30 mV, and showed stability at different pHs, while maintaining their physicochemical properties mostly intact, presenting only a change in their superficial charge (ZP values), indicating their interaction. Both nanoformulations presented interaction with mucins, which anticipates good permeation and bioavailability for oral and topical administration. No cytotoxic effects were observed for lyophilized PLGA NPs encapsulating entacapone, in which 2-hydroxypropyl-ss-cyclodextrin (HP beta CD) was used as a cryoprotectant at 3% concentration (HP-PLGA@Ent), in human hepatocellular carcinoma (HepG2), human neuroblastoma (SH-SY5Y), or human epithelial colorectal adenocarcinoma (Caco-2) cell lines. Conversely, NLCs encapsulating entacapone (W-NLCs@Ent) presented cytotoxic effects on the HepG2 cell line, likely due to intracellular lipid accumulation or storage. Both nanoformulations maintained a COMT inhibition effect in HepG2 cells, using 3-BTD as the COMT probe. An increase of entacapone permeability in both monolayer and coculture models (Caco-2 and Caco-2/HT29-MTX, respectively) was observed for the developed nanoformulations. Overall, this work shows that encapsulated entacapone in different nanocarriers could be a stimulating alternative to solve entacapone setbacks, since they improve its physicochemical properties and permeability while still maintaining the COMT inhibitory activity.

Abstract Mozambique is one of the poorest countries in the world. However, it has natural resources, and if they are managed under sustainable development principles, it can overcome its current problems. In the present socio-economic status, soil is one of its most important resources and must be protected from pollution and degradation. This review identifies and discusses the main soil quality stressors, namely soil fertility; deforestation and its sources: agriculture, timber harvesting, charcoal production, and uncontrolled fires; mining activities, manly gold artisanal explorations, and industrial open-pit coal mining; and solid wastes management. The sustainable use of natural resources is mandatory for future generations to continue to profit from this nature-based wealth.

Abstract <jats:p>Microplastic pollution, particularly particles smaller than 5 mm, poses significant environmental and health risks due to their potential for long-range transport and inhalation. This study provides the first long-term assessment of airborne microplastics in Porto, Portugal, over 18 months (September 2022 to March 2024). Bi-weekly samples were collected using a Microplastic Collector NILU, which were size-fractionated into five categories (&amp;gt;125 μm, 125-63 μm, 63-25 μm, 25-12 μm, and 12-1.2 μm), and quantified via optical microscopy. Microplastics (26 to 1,484 MPs/day/m²) and fibers (14 to 646 fibers/day/m²) showed increasing pollution trends. With a focus on the 12-1.2 μm size-range due to its classification as PM10 and PM2.5, the highest microplastic concentrations were 164 MPs/day/m² (12-1.2 μm) and 534 MPs/day/m² (25-12 μm). Recovery rates of methodology varied among polymers, with PP, PE-HD, and ABS showing high accuracy (75.9%) and PES significantly lower (26.5%). The study highlights significant temporal variability in airborne microplastic pollution, increasing trends, and the need for ongoing monitoring and targeted mitigation strategies to address associated health risks.</jats:p>

Abstract Simple Summary Carbon dots (CDs) are carbon-based nanomaterials with versatile applications, including fluorescence imaging, drug and gene transport, drug delivery, medical diagnosis, and biosensing. In this study, we successfully synthesized various CDs without significantly impacting the cell viability of cancer cells, which suggests the potential for future bioimaging and drug delivery applications. These findings contribute to advancing the potential of CDs in various biomedical research contexts.Abstract Backgroung: The rising complexity and associated side effects of cancer treatments highlight the need for safer and more effective therapeutic agents. Carbon-based nanomaterials such as CDs have been gaining prominence for their unique characteristics, opening avenues for diverse applications such as fluorescence imaging, drug and gene transport, controlled drug delivery, medical diagnosis, and biosensing. Despite promising advancements in research, it remains imperative to scrutinize the properties and potential cytotoxicity of newly developed CDs, ensuring their viability for these applications. Methods: We synthesized four N-doped CDs through a hydrothermal method. Cell viability assays were conducted on A549 and UM-UC-5 cancer cells at a range of concentrations and incubation times, both individually and with the chemotherapeutic agent 5-fluorouracil (5-FU). Results: The obtained results suggest that the newly developed CDs exhibit suitability for applications such as bioimaging, as no significant impact on cell viability was observed for CDs alone.

Abstract Biomass-derived carbon dots (CDs) are gaining much interest in recent times, as they provide a sustainable option with abundant availability, a low cost and tunable luminescence. Herein, we report a simple green synthesis method to produce highly fluorescent CDs from Eucalyptus globulus leaves using the one-pot hydrothermal approach. The fabricated CDs exhibit strong blue fluorescence with an excitation and emission maxima of 320 nm and 445 nm, respectively. The highest quantum yield (QY) obtained was 60.7%. With the reported optical properties and biocompatibility, CDs can be looked at as a promising candidate for potential biosensing applications. Moreover, we employed a life cycle assessment (LCA) cradle-to-gate approach to study the environmental impacts of the synthesis strategy used for the fabrication of CDs. The results point out that citric acid is the main hotspot in CD synthesis, regarding environmental impacts in most categories. This justifies the introduction of biomass, which reduces the amount of citric acid, thus leading to a more sustainable synthesis strategy for fabricating CDs.

Abstract Carotenoids are high added-value products primarily known for their intense coloration and high antioxidant activity. They can be extracted from a variety of natural sources, such as plants, animals, microalgae, yeasts, and bacteria. Gordonia alkanivorans strain 1B is a bacterium recognized as a hyper-pigment producer. However, due to its adaptations to its natural habitat, hydrocarbon-contaminated soils, strain 1B is resistant to different organic solvents, making carotenoid extraction through conventional methods more laborious and inefficient. Ionic liquids (ILs) have been abundantly shown to increase carotenoid extraction in plants, microalgae, and yeast; however, there is limited information regarding bacterial carotenoid extraction, especially for the Gordonia genus. Therefore, the main goal of this study was to evaluate the potential of ILs to mediate bacterial carotenoid extraction and develop a method to achieve higher yields with fewer pre-processing steps. In this context, an initial screening was performed with biomass of strain 1B and nineteen different ILs in various conditions, revealing that tributyl(ethyl)phosphonium diethyl phosphate (IL#18), combined with ethyl acetate (EAc) as a co-solvent, presented the highest level of carotenoid extraction. Afterward, to better understand the process and optimize the extraction results, two experimental designs were performed, varying the amounts of IL#18 and EAc used. These allowed the establishment of 50 mu L of IL#18 with 1125 mu L of EAc, for 400 mu L of biomass (cell suspension with about 36 g/L), as the ideal conditions to achieve maximal carotenoid extraction. Compared to the conventional extraction method using DMSO, this novel procedure eliminates the need for biomass drying, reduces extraction temperatures from 50 degrees C to 22 +/- 2 degrees C, and increases carotenoid extraction by 264%, allowing a near-complete recovery of carotenoids contained in the biomass. These results highlight the great potential of ILs for bacterial carotenoid extraction, increasing the process efficiency, while potentially reducing energy consumption, related costs, and emissions.

Abstract Microplastic pollution, particularly particles smaller than 5 mm, poses significant environmental and health risks due to their potential for inhalation and long-range transport. This study provides the first long-term assessment of airborne microplastics and fibers in Porto, Portugal, over 18 months (September 2022 to March 2024). Bi-weekly samples were collected using a Microplastic Collector NILU, which were size-fractionated into five categories (>125 mu m, 125-63 mu m, 63-25 mu m, 25-12 mu m, and 12-1.2 mu m) and quantified via optical microscopy. Microplastic concentrations ranged from 26 to 1484 MPs/day/m(2), while fiber concentrations varied from 14 to 646 fibers/day/m(2). With a focus on the 12-1.2 mu m size range due to their classifications as PM10 and PM2.5, the highest microplastic concentrations were 164 MPs/day/m(2) (12-1.2 mu m) and 534 MPs/day/m(2) (25-12 mu m). Recovery rates varied among polymers, with PP, PE-HD, and ABS showing high accuracy (75.9%) and PES significantly lower (26.5%). This study highlights the significant temporal variability in airborne microplastic and fiber pollution, correlations with meteorological parameters, and the need for ongoing monitoring and targeted mitigation strategies to address associated health risks.

Abstract Conventional tomato production is widely threatened by environmental changes that impose increasingly frequent and severe conditions of soil salinization and water shortage. The assessment of the wild germplasm has become an appealing strategy for the stress-resilience improvement of crops. Tomato interspecific diversity encompasses wild species that are native to the dry shores and high-elevated deserts of the Andean countries, often thriving under circumstances of drought and salinity. The present work aimed to compare the effects of moderate salinity stress under different watering regimes on the ion distribution, redox homeostasis, osmoregulation, and antioxidant defenses between a domestic cultivar of tomato (Chico III) and the wild tomato species Solanum galapagense (LA1403), Solanum habrochaites (LA1223), and Solanum neorickii (LA2194). Results showed that although wild tomato plants grew slower than the cultivar, their growth was less affected by exposure to salt or to lower water availability. S. galapagense revealed a Na+ includer behavior under salt stress, increasing Na+ levels by 6-fold over control, reaching levels 4 times higher than in the cultivar. Nonetheless, H2O2-detoxifying enzymes were activated, and shoot elongation was sustained in this species, suggesting an efficient Na+ compartmentalization. On the other hand, the domestic cultivar had the highest accumulation of Na+ in roots and showed the lowest ability to sustain growth under combined stress. Leaves of S. habrochaites showed a huge proline buildup under salt stress, whereas S. neorickii and S. galapagense seemed to prevent proline accumulation. S. habrochaites also had high levels of antioxidant metabolites and superoxide dismutase activity under control conditions but downregulated further antioxidant defenses in response to stress exposure. No oxidative damages were noticed despite the almost 2-fold increase in ROS content in the leaves of S. neorickii under salt stress, which showed a negative correlation with growth traits, but an improvement in the antioxidant potential. A principal component analysis (PCA) revealed five PCs with eigenvalues >1, explaining 84 % of the total variability, and suggesting a separation of the evaluated samples mainly in accordance with the type of redox disturbances and antioxidant defenses employed, levels of photosynthetic pigments, balance between Na+ and K+ uptake and proline accumulation. These findings show that wild tomato plants respond differently than cultivated ones under moderate salinity and reduced water availability, suggesting interesting osmoregulatory and antioxidant mechanisms in S. galapagense and S. habrochaites.