Browsing by Author "Pintado, Maria Manuela"
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- Alginate: Pharmaceutical and Medical ApplicationsPublication . Batista, Patrícia; Morais, Alcina M. M. B.; Pintado, Maria Manuela; Morais, Rui M. S. C.Due to their outstanding properties in terms of mild gelation conditions and simple functionalization, biocompatibility, low toxicity, biodegradability, non-antigenicity and chelating ability, as well as relatively low cost, alginates have been widely used in a variety of biomedical applications including tissue engineering and drug delivery systems. Smart alginate hydrogels for on-demand drug release in response to environmental stimuli and 3D bioprinting will play an important role in the future. These and the introduction of appropriate cell interactive features will be crucial for many tissue engineering applications. The focus of the present chapter is to highlight the great potential of the alginates as biomaterial for biomedical applications and to discuss the role that alginate-based materials are likely to play in biomedical applications in the future.
- Bioactive hydrolysates from chlorella vulgaris: optimal process and bioactive propertiesPublication . Cunha, Sara A.; Coscueta, Ezequiel R.; Nova, Paulo; Silva, Joana Laranjeira; Pintado, Maria ManuelaMicroalgae have been described as a source of bioactive compounds, such as peptides. Microalgae are easy to produce, making them a sustainable resource for extracting active ingredients for industrial applications. Several microalgae species have interesting protein content, such as Chlorella vulgaris with around 52.2% of protein, making it promising for peptide hydrolysate production. Therefore, this work focused on the production of water-soluble hydrolysates rich in proteins/peptides from the microalgae C. vulgaris and studied bioactive properties. For that, a design of experiments (DOE) was performed to establish the optimal conditions to produce hydrolysates with higher levels of protein, as well as antioxidant and antihypertensive properties. Four experimental factors were considered (cellulase percentage, protease percentage, hydrolysis temperature, and hydrolysis duration) for three responses (protein content, antioxidant activity, and antihypertensive activity). The optimal conditions determined by the DOE allowed producing a scaled-up hydrolysate with 45% protein, with antioxidant activity, measured by oxygen radical absorbance capacity assay, of 1035 µmol TE/g protein, IC50 for angiotensin-converting enzyme inhibition activity of 286 µg protein/mL, and α-glucosidase inhibition of 31% (30 mg hydrolysate/mL). The obtained hydrolysates can be used as functional ingredients for food and nutraceuticals due to their antioxidant, antihypertensive, and antidiabetic potential. Moreover, the antioxidant potential of the extracts may be relevant for the cosmetic industry, especially in antiaging formulations.
- Bioprospecting bioactive peptides in halobatrachus didactylus body mucus: from in silico insights to essential in vitro validationPublication . Cunha, Marta Fernandez; Coscueta, Ezequiel R.; Brassesco, María Emilia; Almada, Frederico; Gonçalves, David; Pintado, Maria ManuelaFish body mucus plays a protective role, especially in Halobatrachus didactylus, which inhabits intertidal zones vulnerable to anthropogenic contaminants. In silico predicted bioactive peptides were identified in its body mucus, namely, EDNSELGQETPTLR (HdKTLR), DPPNPKNL (HdKNL), PAPPPPPP (HdPPP), VYPFPGPLPN (HdVLPN), and PFPGPLPN (HdLPN). These peptides were studied in vitro for bioactivities and aggregation behavior under different ionic strengths and pH values. Size exclusion chromatography revealed significant peptide aggregation at 344 mM and 700 mM ionic strengths at pH 7.0, decreasing at pH 3.0 and pH 5.0. Although none exhibited antimicrobial properties, they inhibited Pseudomonas aeruginosa biofilm formation. Notably, HdVLPN demonstrated potential antioxidant activity (ORAC: 1.560 μmol TE/μmol of peptide; ABTS: 1.755 μmol TE/μmol of peptide) as well as HdLPN (ORAC: 0.195 μmol TE/μmol of peptide; ABTS: 0.128 μmol TE/μmol of peptide). Antioxidant activity decreased at pH 5.0 and pH 3.0. Interactions between the peptides and mucus synergistically enhanced antioxidant effects. HdVLPN and HdLPN were non-toxic to Caco-2 and HaCaT cells at 100 μg of peptide/mL. HdPPP showed potential antihypertensive and antidiabetic effects, with IC50 values of 557 μg of peptide/mL for ACE inhibition and 1700 μg of peptide/mL for α-glucosidase inhibition. This study highlights the importance of validating peptide bioactivities in vitro, considering their native environment (mucus), and bioprospecting novel bioactive molecules while promoting species conservation.
- Characterization of solid lipid nanoparticles produced with carnauba wax for rosmarinic acid oral deliveryPublication . Madureira, Ana Raquel; Campos, Débora A.; Fonte, Pedro; Nunes, Sara; Reis, Flávio; Gomes, Ana Maria; Sarmento, Bruno; Pintado, Maria ManuelaIn the last decade, research studies have increased on the development of delivery systems for polyphenols, for protection, improvement of stability and increase of their bioavailability. Rosmarinic acid is a polyphenol with described bioactivities, such as antioxidant, anti-mutagenic, anti-bacterial and anti-viral capabilities. Thus, the aim of this research work was to produce stable solid lipid nanoparticles (SLN) using carnauba wax as lipidic matrix, for delivery of rosmarinic acid, to be further incorporated into food matrices. Hence, different concentrations of wax (0.5, 1 and 1.5%, w/v) and percentages of surfactant (1, 2 and 3%, v/v) were tested. Physical properties, surface morphology and association efficiencies were studied at time of production and after 28 day at refrigerated storage. Thermal properties and the nature of the chemical interactions between the lipids waxes and rosmarinic acid were also evaluated. The particles showed range size between 35-927 nm and zeta potentials of ca. -38 to 40, showing high stability, with no risk of aggregation due to electric repulsion of SLN. High association efficiencies % (ca. 99%) were obtained. FTIR analyses proved the association of rosmarinic acid and lipidic matrix. The low lipid and high surfactant concentrations leads to small SLN. The surfactant, polysorbate 80 decreases the interfacial tension in the SLN surfaces, preventing aggregation, leading to the development of small particles. These properties were maintained throughout the 28 day of refrigerated storage, and no rosmarinic acid was released by the particles during refrigeration, indicating good compatibility between rosmarinic acid and the waxy core of SLN. The optimum range values to obtain the desirable features for incorporation in a functional food suggest formulations containing 1.0 and 1.5% (w/v) of lipid and 2% (v/v) of surfactant.
- Characterization of the microstructure of Terrincho ewe cheesePublication . Gomes, A. M. P.; Braga, T. M.; Pintado, Ana I. E.; Pintado, Maria Manuela; Malcata, F. XavierThe microstructure of Terrincho cheese – a Portuguese traditional cheese bearing a Protected Denomination of Origin, was assessed by scanning electron microscopy (SEM). Terrincho cheese was manufactured according to the traditional protocol using pre-filtered, plain raw ewe’s milk of Churra da Terra Quente breed, without addition of starter of any other type of cultures, and coagulated with animal rennet. The cheeses were salted upon unmoulding, and placed in ripening chambers held at 10–12 °C and 88–89 % relative humidity for a period of 30 days. Cheeses were sampled at 0, 15 and 30 days. Cheese specimens were prepared for SEM by fixing small blocks of cheese (cut from freshly sampled cheeses) in formaldehyde, at room temperature for 1 month, cutting it into 1–2 mm thick slices using sharp razor blades and dehydrating in a graded ethanol series. Slices in absolute ethanol were critical point dried from carbon dioxide, mounted on SEM stubs using adhesive tabs, sputter-coated with gold, and examined using a JEOL scanning electron microscope. The microstructure of the (semi-soft) curd of Terrincho cheese appeared as a continuous casein network possessing a spongy appearance. The various microbial populations present within the cheese were found to grow in the form of colonies, embedded in the casein network and close to the void spaces originally occupied by fat. Microbial colonies were roughly spherical, with bacteria tightly packed in the centre. A similar pattern of microbial growth was observed throughout ripening. Other inclusions were also pinpointed, namely salt crystals.
- Collagen-based bioactive hydrolysates production from Blue Shark skinPublication . Brassesco, M. E.; Coscueta, E. R.; Pintado, Maria ManuelaPortugal is the country with the highest levels of fish consumption in the world with an average of 59 kg per capita year. As a result, a huge amount of fish residues is produced, of which up to 30% may be skin and bone. Is well-known that fish skin has more than 80% of its total protein content as collagen. This structural protein is present in the extracellular matrices of animals and has widely applications in food, cosmetic, biomedical, and pharmaceutical industries. For decades, the main industrial exploitations of collagen have been bovine and porcine origins. However, due to religious beliefs and infectious diseases, other collagen sources are being debated. In this regard, the use of collagen with marine origin is being considered highly attractive by the industry as an important alternative source. Blue shark skin, which is an abundant by-product of Portugal processing industry rich in collagen, represents a potential source of this protein. Thus, a collagen hydrolysate was obtained from Blue Shark skin with bromelain, a plant enzyme, for the first time. As a result, low molecular weight hydrolysates were obtained with a protein concentration of 0.5%(p/p). The antioxidant activity was analysed in vitro, obtaining a result of 4.077 µmol Trolox Equivalent/mg protein. The ACE inhibition activity was also analysed obtaining an IC50 of 14.3 ug protein/mL at 1h hydrolysis. Therefore, it was possible to obtain an ingredient (hydrolysed collagen) that is currently required by industries such as cosmetic, food and nutraceutical, with high potential antioxidant and antihypertensive activities. For this, it was possible to apply a sustainable process that consumes less time and uses an alternative and abundant raw material.
- Development of a neuropsychophysiological protocol to evaluate oral films for the delivery of neuroactive substancesPublication . Batista, Patrícia; Fernandes, Eugénia; Ribeiro, Fabiana; Moreno, Ana; Oliveira-Silva, Patrícia; Pintado, Maria Manuela
- Effects of microencapsulated phenethyl isothiocyanate on gastrointestinal cancer cells and pathogenic bacteriaPublication . Abrantes, Rafaela; Ramos, Cátia C.; Coscueta, Ezequiel R.; Costa, João; Gomes, Joana; Gomes, Catarina; Reis, Celso A.; Pintado, Maria ManuelaGastrointestinal cancers remain a global health burden, demanding more effective prevention and treatments. Phenethyl isothiocyanate (PEITC), a compound derived from cruciferous vegetables, stands out as a promising nutraceutical agent due to its chemopreventive and therapeutic properties. However, its therapeutic translation remains limited mainly due to its poor water solubility and rapid metabolism. Herein, we encapsulated PEITC into biocompatible chitosan-based microparticles with an extra virgin olive oil core to improve its bioavailability and stability. Pure PEITC's biocompatibility and microencapsulated PEITC's stability and antibacterial activity were evaluated. The antibacterial activity analysis showed microencapsulated PEITC as a promising antibacterial agent against gastrointestinal pathogenic bacteria (two Gram-positive and two Gram-negative). The impact of both pure and microencapsulated PEITC was assessed on gastrointestinal cancer cells (MKN45 gastric cancer and SW48 colon cancer cell lines). PEITC exhibited threshold or hormetic dose-dependent toxicity in colon fibroblasts and decreased gastric cancer cells' migration capacity, enhanced upon encapsulation into microparticles. In addition, microencapsulated PEITC induced downregulation of phosphorylated AKT, FAK, and ERK1/2 proteins, disrupting motility signaling pathways and tubulin expression. These findings suggest that the delivery of PEITC via chitosan-based microparticles holds promise as a nutraceutical delivery strategy against gastrointestinal disorders that predispose to cancer.
- Emerging technologies to extract high added value compounds from fruit residues: sub/supercritical, ultrasound-, and enzyme-assisted extractionsPublication . Alexandre, Elisabete M. C.; Moreira, Sílvia A.; Castro, Luís M. G.; Pintado, Maria Manuela; Saraiva, Jorge A.Food waste is a growing problem for the food industry, leading to an increase of pollution and economic problems. Fruits and vegetables are very rich in bioactive compounds having many benefits for humans. These biocompounds can be found not only in the fruit/vegetable itself but also in its wastes, after processing. Nonetheless, the conventional extraction methods are highly problematic, due to solvent consumption, long extraction time, and low extraction yields, making it necessary to develop new extraction techniques. In this review, we aim to review the most recent literature on the extraction of bioactive compounds from fruit peels and seeds, using sub/supercritical fluids, ultrasound, and enzymes.
- Environmental footprint of emerging technologies, regulatory and legislative issuesPublication . Castro, Sónia M.; Inácio, Rita S.; Alexandre, Elisabete M. C.; Fidalgo, Liliana G.; Pereira, Sofia; Quaresma, Patrícia; Freitas, Paulo; Teixeira, Paula; Pintado, Maria Manuela; Gomes, Ana M.; Tonello, Carole; Saraiva, Jorge A.Consumers are more demanding, better educated in terms of food quality and nutritional aspects, and forcing producers along with regulatory agencies to search for alternative processing technologies. Some of these technologies like high pressure, pulsed electrical fields, supercritical CO2, ultrasound, ozone, or plasma treatment are at industrially use, pilot scale, or even at the edge of application, but the most successful ones at the moment, with already a wide variety of commercial products, are high hydrostatic pressure and pulsed electrical fields. These technologies offer better products, both “natural” in terms of fresh-like flavor and ingredients and safe with extended shelf-life. This tendency leads to the need for a global regulation system that ensures quality of food regardless of country of origin and, at the same time, without compromising safety. In addition to this system, there should be governing bodies that regulate and monitor the enforcement of these food-processing regulations, to avoid regulations that often only apply to countries belonging to specific organizations. Together with food legislation concerns, sustainable food manufacturing and related efficient energy use have also became priorities of the food industries. While conventional preservation processes (e.g., canning, freezing, drying) mainly use thermal energy, more complex processes use mechanical, electromagnetic, electrical, and other forms of energy, which can reduce the energy consumption. Indeed the efficient use of resources in food industry is a critical element for the future generations for sustainable food processing, but the impact of energy requirements in emerging technologies has not been a matter of intense discussion. The objective of this chapter is to provide a concise overview of environmental footprint of emerging technologies, namely high-pressure processing and pulsed electric fields, and their current related food legislation status in various countries.