12 results on '"Macedo, Ana S."'
Search Results
2. Novel and revisited approaches in nanoparticle systems for buccal drug delivery
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Macedo, Ana S., Castro, Pedro M., Roque, Luís, Thomé, Natália G., Reis, Catarina P., Pintado, Manuela E., and Fonte, Pedro
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- 2020
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3. Advances in Pancreatic Cancer Treatment by Nano-Based Drug Delivery Systems.
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Viegas, Cláudia, Patrício, Ana B., Prata, João, Fonseca, Leonor, Macedo, Ana S., Duarte, Sofia O. D., and Fonte, Pedro
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PANCREATIC cancer ,NANOMEDICINE ,DRUG delivery systems ,CANCER treatment ,SURVIVAL rate ,NANOCARRIERS - Abstract
Pancreatic cancer represents one of the most lethal cancer types worldwide, with a 5-year survival rate of less than 5%. Due to the inability to diagnose it promptly and the lack of efficacy of existing treatments, research and development of innovative therapies and new diagnostics are crucial to increase the survival rate and decrease mortality. Nanomedicine has been gaining importance as an innovative approach for drug delivery and diagnosis, opening new horizons through the implementation of smart nanocarrier systems, which can deliver drugs to the specific tissue or organ at an optimal concentration, enhancing treatment efficacy and reducing systemic toxicity. Varied materials such as lipids, polymers, and inorganic materials have been used to obtain nanoparticles and develop innovative drug delivery systems for pancreatic cancer treatment. In this review, it is discussed the main scientific advances in pancreatic cancer treatment by nano-based drug delivery systems. The advantages and disadvantages of such delivery systems in pancreatic cancer treatment are also addressed. More importantly, the different types of nanocarriers and therapeutic strategies developed so far are scrutinized. [ABSTRACT FROM AUTHOR]
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- 2023
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4. Fusions of a carbohydrate binding module with the small cationic hexapeptide RWRWRW confer antimicrobial properties to cellulose-based materials.
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Barbosa, Mariana, Simões, Hélvio, Pinto, Sandra N., Macedo, Ana S., Fonte, Pedro, and Prazeres, D.Miguel F.
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MOLECULAR recognition ,CARBOHYDRATES ,ESCHERICHIA coli ,DRUG resistance in bacteria ,CLOSTRIDIUM thermocellum ,HEXAPEPTIDES - Abstract
The emergence of antibiotic-resistant bacteria is a critical worldwide healthcare problem. In the specific case of wound care, new and effective alternatives to currently available solutions are urgently needed. Cellulose-based dressings, for example, could be made more attractive if rendered antimicrobial. This work proposes a new strategy to modify cellulose-based materials with the short antimicrobial hexapeptide MP196 (RWRWRW - NH 2) that relies on a biomolecular recognition approach based on carbohydrate binding modules (CBMs). Specifically, we focused on the modification of hydrogels, paper, and microfibrillated cellulose (MFC) with fusions of the CBM3 from Clostridium thermocellum (C. thermocellum) with derivatives of MP196. The fusions are prepared by promoting the formation of a disulfide bond between Cys-terminated derivatives of MP196 and a CBM3 that is pre-anchored in the materials. The CBM3-MP196-modified materials displayed antibacterial activity against Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) that was significantly higher when compared with the activity of materials prepared by physical adsorption of MP196. The biomolecular strategy provides a more favorable orientation, exposure, and distancing of the peptide from the matrix. This versatile concept provides a toolbox for the functionalization of cellulose materials of different origins and architectures with a broad choice in peptides. Functionalization under mild biological conditions avoids further purification steps, allowing for translational research and multiple applications as drug delivery systems, scaffolds for tissue engineering and biomaterials. The emergence of antibiotic-resistant bacteria is a critical worldwide healthcare problem. In the specific case of wound care, new and effective alternatives to currently available solutions are urgently needed. This work proposes a new strategy to modify cellulose-based materials with a short antimicrobial hexapeptide that relies on a biomolecular recognition approach based on carbohydrate binding modules. The modified materials displayed antibacterial activity against both Gram-negative and Gram-positive bacteria. The biomolecular strategy provides a favorable orientation, exposure, and distancing of the peptide from the matrix. This versatile concept offers a toolbox for the functionalization of different cellulose materials with a broad choice in peptides. Functionalization under mild biological conditions avoids further purification steps, allowing for translational research and multiple applications. [Display omitted] [ABSTRACT FROM AUTHOR]
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- 2022
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5. Optimization of the brewing parameters on coffee extraction using a central composite rotatable design.
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Barroso, Lívia Alves, Macedo, Ana S., Lemos, Iara Lopes, de Andrade Neves, Nathália, Schmiele, Marcio, da Silveira, João Vinícios Wirbitzki, Amaral, Tatiana Nunes, and Fonte, Pedro
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COFFEE brewing , *COFFEE , *COFFEE grounds , *INDUSTRIAL capacity , *CAFFEINE - Abstract
Background: The consumption of cold brew is relatively new, and guidelines with conditions and parameters to produce cold brew are still lacking. In this study, the parameters to obtain cold brew coffee from Coffea arabica were optimized to obtain a coffee extract rich in caffeine and soluble solids. The effects of extraction time, particle size of ground coffee, extraction temperature, coffee‐to‐water ratio, stirring on caffeine yield, and soluble solids on caffeine concentrations were studied. Results: Optimized parameters showed 45 min sufficed to perform a cold extraction at 4°C and 24°C. The parameters selected for validation were 24°C, 30% coffee‐to‐water ratio, a stirring of 400 rpm resulting in 3.98 mg/ml of extracted caffeine, 11.20 °Brix, and 93.9% of caffeine yield. The smaller particle size (595 μm) displayed the higher caffeine extraction of about 4 mg/ml. Conclusion: This study reveals the high efficiency of cold brew extraction and its potential at the industrial scale, decreasing costs with energy and extraction time, and producing a coffee rich in caffeine and soluble solids. [ABSTRACT FROM AUTHOR]
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- 2022
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6. Design and synthesis of novel quinic acid derivatives: in vitro cytotoxicity and anticancer effect on glioblastoma.
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Murugesan, Akshaya, Holmstedt, Suvi, Brown, Kenna C, Koivuporras, Alisa, Macedo, Ana S, Nguyen, Nga, Fonte, Pedro, Rijo, Patrícia, Yli-Harja, Olli, Candeias, Nuno R, and Kandhavelu, Meenakshisundaram
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- 2020
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7. Nanoemulsions for delivery of flavonoids: formulation and in vitro release of rutin as model drug.
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Macedo, Ana S., Quelhas, Sara, Silva, Amélia M., and Souto, Eliana B.
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FLAVONOIDS ,RUTIN ,MICROSCOPY ,LIGHT scattering ,DRUG solubility - Abstract
The aim of the present study is to design and characterize a rutin-loaded nanoemulsion (RT-NE) and determine the release profile of the drug in vitro. RT-NE was prepared by a high pressure homogenization technique. The obtained droplets were analyzed by optical microscopy and were shown to be of spherical shape. By dynamic light scattering, characterization of RT-NE showed an average diameter of 127 nm, polydispersity index of 0.168 and zeta potential values near neutrality (−3.49 mV). Encapsulation efficiency was of ∼82% (82.3 ± 1.62%). Drug release was characterized by an initial burst which decreased over the time, showing a sustained release profile. After 24 h, rutin released from NE reached nearly 65%. The developed system proved to be stable and suitable to encapsulating poorly water-soluble drugs. [ABSTRACT FROM AUTHOR]
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- 2014
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8. Characterization of antibiotic resistant enterococci isolated from untreated waters for human consumption in Portugal
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Macedo, Ana S., Freitas, Ana R., Abreu, Cristina, Machado, Elisabete, Peixe, Luísa, Sousa, João C., and Novais, Carla
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DRINKING water microbiology , *DRUG resistance in microorganisms , *ANTIBIOTICS , *ENTEROCOCCUS , *FOOD composition , *MICROBIAL virulence , *ECOLOGICAL niche , *FOOD microbiology - Abstract
Abstract: Untreated drinking water is frequently overlooked as a source of antibiotic resistance in developed countries. To gain further insight on this topic, we isolated the indicator bacteria Enterococcus spp. from water samples collected in wells, fountains and natural springs supplying different communities across Portugal, and characterized their antibiotic resistance profile with both phenotypic and genetic approaches. We found various rates of resistance to seven antibiotic families. Over 50% of the isolates were resistant to at least ciprofloxacin, tetracyclines or quinupristin–dalfopristin and 57% were multidrug resistant to ≥3 antibiotics from different families. Multiple enterococcal species (E. faecalis, E. faecium, E. hirae, E. casseliflavus and other Enterococcus spp) from different water samples harbored genes encoding resistance to tetracyclines, erythromycin or gentamicin [tet(M)-46%, tet(L)-14%, tet(S)-5%, erm(B)-22%, aac(6´)-Ie-aph(2″)-12%] and putative virulence factors [gel-28%, asa1-16%]. The present study positions untreated drinking water within the spectrum of ecological niches that may be reservoirs of or vehicles for antibiotic resistant enterococci/genes. These findings are worthy of attention as spread of antibiotic resistant enterococci to humans and animals through water ingestion cannot be dismissed. [Copyright &y& Elsevier]
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- 2011
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9. Evaluation of the Antitumour and Antiproliferative Effect of Xanthohumol-Loaded PLGA Nanoparticles on Melanoma.
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Fonseca, Magda, Macedo, Ana S., Lima, Sofia A. Costa, Reis, Salette, Soares, Raquel, and Fonte, Pedro
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OVERALL survival , *PHENOTYPIC plasticity , *NANOPARTICLE size , *SURVIVAL rate , *NANOPARTICLES - Abstract
Cutaneous melanoma is the deadliest type of skin cancer and current treatment is still inadequate, with low patient survival rates. The polyphenol xanthohumol has been shown to inhibit tumourigenesis and metastasization, however its physicochemical properties restrict its application. In this work, we developed PLGA nanoparticles encapsulating xanthohumol and tested its antiproliferative, antitumour, and migration effect on B16F10, malignant cutaneous melanoma, and RAW 264.7, macrophagic, mouse cell lines. PLGA nanoparticles had a size of 312 ± 41 nm and a PdI of 0.259, while achieving a xanthohumol loading of about 90%. The viability study showed similar cytoxicity between the xanthohumol and xanthohumol-loaded PLGA nanoparticles at 48 h with the IC50 established at 10 µM. Similar antimigration effects were observed for free and the encapsulated xanthohumol. It was also observed that the M1 antitumor phenotype was stimulated on macrophages. The ultimate anti-melanoma effect emerges from an association between the viability, migration and macrophagic phenotype modulation. These results display the remarkable antitumour effect of the xanthohumol-loaded PLGA nanoparticles and are the first advance towards the application of a nanoformulation to deliver xanthohumol to reduce adverse effects by currently employed chemotherapeutics. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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10. Elastic and Ultradeformable Liposomes for Transdermal Delivery of Active Pharmaceutical Ingredients (APIs).
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Souto, Eliana B., Macedo, Ana S., Dias-Ferreira, João, Cano, Amanda, Zielińska, Aleksandra, and Matos, Carla M.
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LIPOSOMES , *THERAPEUTICS , *SUBCUTANEOUS injections , *CELL anatomy , *CELL membranes , *SKIN permeability , *PHOSPHOLIPIDS , *DRUG delivery systems - Abstract
Administration of active pharmaceutical ingredients (APIs) through the skin, by means of topical drug delivery systems, is an advanced therapeutic approach. As the skin is the largest organ of the human body, primarily acting as a natural protective barrier against permeation of xenobiotics, specific strategies to overcome this barrier are needed. Liposomes are nanometric-sized delivery systems composed of phospholipids, which are key components of cell membranes, making liposomes well tolerated and devoid of toxicity. As their lipid compositions are similar to those of the skin, liposomes are used as topical, dermal, and transdermal delivery systems. However, permeation of the first generation of liposomes through the skin posed some limitations; thus, a second generation of liposomes has emerged, overcoming permeability problems. Various mechanisms of permeation/penetration of elastic/ultra-deformable liposomes into the skin have been proposed; however, debate continues on their extent/mechanisms of permeation/penetration. In vivo bioavailability of an API administered in the form of ultra-deformable liposomes is similar to the bioavailability achieved when the same API is administered in the form of a solution by subcutaneous or epi-cutaneous injection, which demonstrates their applicability in transdermal drug delivery. [ABSTRACT FROM AUTHOR]
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- 2021
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11. Nanocarrier-Mediated Topical Insulin Delivery for Wound Healing.
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Macedo, Ana S., Mendes, Francisca, Filipe, Patrícia, Reis, Salette, and Fonte, Pedro
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INSULIN , *CHRONIC wounds & injuries , *WOUND care , *GROWTH factors , *WOUND healing , *DIAGNOSIS , *INSULIN aspart - Abstract
Wound care has been clinically demanding due to inefficacious treatment that represents an economic burden for healthcare systems. In Europe, approximately 7 million people are diagnosed with untreated wounds, leading to a cost between 6.000€ and 10.000€ per patient/year. In the United States of America, 1.5 million people over 65 years old suffer from chronic wounds. A promising therapeutic strategy is the use of exogenous growth factors because they are decreased at the wound site, limiting the recovery of the skin. Insulin is one of the cheapest growth factors in the market able to accelerate the re-epithelialization and stimulate angiogenesis and cell migration. However, the effectiveness of topical insulin in wound healing is hampered by the proteases in the wound bed. The encapsulation into nanoparticles improves its stability in the wound, providing adhesion to the mucosal surface and allowing its sustained release. The aim of this review is to perform a standing point about a promising strategy to treat different types of wounds by the topical delivery of insulin-loaded nanocarriers. [ABSTRACT FROM AUTHOR]
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- 2021
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12. An Overview on Spray-Drying of Protein-Loaded Polymeric Nanoparticles for Dry Powder Inhalation.
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Marante, Tânia, Viegas, Cláudia, Duarte, Inês, Macedo, Ana S., and Fonte, Pedro
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SPRAY drying ,NANOCARRIERS ,PROTEIN stability ,NANOPARTICLES ,POWDERS ,SURFACE area ,IN vitro studies ,POLYMERIC nanocomposites - Abstract
The delivery of therapeutic proteins remains a challenge, despite recent technological advances. While the delivery of proteins to the lungs is the gold standard for topical and systemic therapy through the lungs, the issue still exists. While pulmonary delivery is highly attractive due to its non-invasive nature, large surface area, possibility of topical and systemic administration, and rapid absorption circumventing the first-pass effect, the absorption of therapeutic proteins is still ineffective, largely due to the immunological and physicochemical barriers of the lungs. Most studies using spray-drying for the nanoencapsulation of drugs focus on the delivery of conventional drugs, which are less susceptible to bioactivity loss, compared to proteins. Herein, the development of polymeric nanoparticles by spray-drying for the delivery of therapeutic proteins is reviewed with an emphasis on its advantages and challenges, and the techniques to evaluate their in vitro and in vivo performance. The protein stability within the carrier and the features of the carrier are properly addressed. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
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