Percorrer por autor "Viegas, Cláudia"
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- Advances in Pancreatic Cancer treatment by Nano-Based drug delivery systemsPublication . Viegas, Cláudia; Patrício, Ana B.; Prata, João; Fonseca, Leonor; Macedo, Ana S.; Duarte, Sofia O. D.; Fonte, PedroPancreatic 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.
- An insight on lipid nanoparticles for therapeutic proteins deliveryPublication . Viegas, Cláudia; Seck, Fatumata; Fonte, PedroTherapeutic proteins are well-tolerated bioactive compounds used in different therapies, due to its high speci-ficity and biopotency. Nevertheless, they may also present some physicochemical instability, leading to loss of bioactivity hampering treatments. This can be avoided by its loading into lipid nanoparticles, which are biocompatible and biodegradable carriers. The use of lipids nanoparticles to deliver therapeutic proteins over-comes different challenges, allowing its administration by all delivery routes. Thus, therapeutic proteins may be loaded into liposomes, the first developed lipid-based nanocarriers composed of phospholipid bilayers, solid lipid nanoparticles composed of a solid lipid matrix, or nanostructured lipid carriers made of a blend of liquid and solid lipid as matrix. The latter are currently marking the trend in lipid nanocarriers due to its high loading capacity, good stability upon storage and better sustained release pattern. Production methods must focus both on attaining the desired nanocarrier features, and maintenance of therapeutic proteins structure and bioactivity. This review aims to make an insight overview on the application of lipid nanoparticles to deliver therapeutic proteins, showing its potential in different therapies. A special focus is given to the production techniques to obtain therapeutic proteins-loaded lipid nanoparticles.
- Camptothecin-loaded mesoporous silica nanoparticles functionalized with CpG oligodeoxynucleotide as a new approach for skin cancer treatmentPublication . Qureshi, Munibah; Viegas, Cláudia; Duarte, Sofia O.D.; Girardi, Michael; Shehzad, Adeeb; Fonte, PedroThe therapeutic efficacy of camptothecin (CPT), a potent antitumor alkaloid, is hindered by its hydrophobic nature and instability, limiting its clinical use in treating cutaneous squamous cell carcinoma (SCC). This study introduces a novel nano drug delivery system (NDDS) utilizing functionalized mesoporous silica nanoparticles (FMSNs) for efficient CPT delivery. The FMSNs were loaded with CPT and subsequently coated with chitosan (CS) for enhanced stability and bioadhesion. Importantly, CpG oligodeoxynucleotide (CpG ODN) was attached onto the CS-coated FMSNs to leverage the immunostimulatory properties of CpG ODN, augmenting the chemotherapy's efficacy. The final formulation FMSN-CPT-CS-CpG displayed an average size of 241 nm and PDI of 0.316 with an encapsulation efficiency of 95 %. Comprehensive in vitro and in vivo analyses, including B16F10 cells and DMBA/TPA-induced SCC murine model, demonstrated that the FMSN-CPT-CS-CpG formulation significantly enhanced cytotoxicity against B16F10 cells and induced complete regression in 40 % of the in vivo subjects, surpassing the efficacy of standard CPT and FMSN-CPT treatments. This study highlights the potential of combining chemotherapeutic and immunotherapeutic agents in an NDDS for targeted, efficient skin cancer treatment.
- Enhanced anticancer activity of Hymenocardia acida stem bark extract loaded into PLGA nanoparticlesPublication . Adedokun, Oluwasegun; Ntungwe, Epole N.; Viegas, Cláudia; Adesina Ayinde, Bunyamin; Barboni, Luciano; Maggi, Filippo; Saraiva, Lucilia; Rijo, Patrícia; Fonte, PedroHymenocardia acida (H. acida) is an African well-known shrub recognized for numerous medicinal properties, including its cancer management potential. The advent of nanotechnology in delivering bioactive medicinal plant extract with poor solubility has improved the drug delivery system, for a better therapeutic value of several drugs from natural origins. This study aimed to evaluate the anticancer properties of H. acida using human lung (H460), breast (MCF-7), and colon (HCT 116) cancer cell lines as well as the production, characterization, and cytotoxicity study of H. acida loaded into PLGA nanoparticles. Benchtop models of Saccharomyces cerevisiae and Raniceps ranninus were used for preliminary toxicity evaluation. Notable cytotoxic activity in benchtop models and human cancer cell lines was observed for H. acida crude extract. The PLGA nanoparticles loading H. acida had a size of about 200 nm and an association efficiency of above 60%, making them suitable to be delivered by different routes. The outcomes from this research showed that H. acida has anticancer activity as claimed from an ethnomedical point of view; however, a loss in activity was noted upon encapsulation, due to the sustained release of the drug.
- Impact of the use of cryoprotectants in the production of freeze-dried soluble coffee from cold brew arabica coffeePublication . Barroso, Livia Alves; Viegas, Cláudia; Stančiauskaitė, Monika; Macedo, Ana S.; Lemos, Iara Lopes; da Costa, Joyce Maria Gomes; Schmiele, Marcio; da Silveira, João Vinícios Wirbitzki; Brandão, Pedro; Amaral, Tatiana Nunes; Fonte, PedroCold brew is a method of coffee extraction that uses low temperature, preserving the volatile compounds of coffee. Freeze-drying allows the preservation of coffee features and nutritional value. The aim of this study was to evaluate the effects of different cryoprotectants in cold brew extracts as a basis for freeze-dried coffee production. Thus, the Coffea arabica extracts and the soluble coffee were characterized concerning caffeine content, antioxidant capacity, total phenolic compounds, and antimicrobial activity to verify the potential of this method. The extracts did not show antimicrobial activity with a high soluble solid content. It was observed that the cold extraction methods were efficient regarding the caffeine content, antioxidant capacity, and total phenolic compounds. Freeze-dried coffees also did not show antimicrobial activity, and they maintained the water and humidity activity standards. In general, cryoprotectants displayed an unfavorable influence on the extract and freeze-dried coffee in the analyses performed. The coffee extract without cryoprotectants had a higher antioxidant capacity (88.12%) and content of phenolic compounds (7.74 mg AG/mL of the coffee extract). Only for the analyses of soluble solids, the cryoprotectants mannitol and fructose showed promising results (14.03 degrees Brix, 14.40 degrees Brix, 11.33 degrees Brix, respectively). Thus, for the analyses conducted, the cryoprotectants did not lead to significant advantages for this process.
- Lipid-based carriers for food ingredients deliveryPublication . Barroso, Livia; Viegas, Cláudia; Vieira, Joao; Ferreira-Pego, Cintia; Costa, Joyce; Fonte, PedroThe encapsulation in the food industry has gained relevant importance, mainly due to its contribution to solve food problems by reducing the loss of nutrients, prolong the shelf-life, and improve food quality and safety. The lipid-based delivery systems as microemulsions, liposomes, solid lipid nanoparticles and nanostructured lipid carriers are widely used to deliver food ingredients due to their ability to protect and deliver it, enhancing its functionality and bioavailability. Despite the benefits on delivering food ingredients the toxicity profile of such carriers is usually neglected. The aim of this review is to provide a detailed overview on the application of lipid-based carriers to deliver food ingredients. Herein, the encapsulation advantages and disadvantages, and microencapsulation techniques used to obtain lipid-based carriers are discussed. More importantly, the different types of lipid-based carriers used for food ingredients delivery are thoroughly scrutinized, as well as their application in foods and possible toxicity concerns.
- Solid lipid nanoparticles vs. nanostructured lipid carriers: a comparative reviewPublication . Viegas, Cláudia; Patrício, Ana B.; Prata, João M.; Nadhman, Akhtar; Chintamaneni, Pavan Kumar; Fonte, PedroSolid–lipid nanoparticles and nanostructured lipid carriers are delivery systems for the delivery of drugs and other bioactives used in diagnosis, therapy, and treatment procedures. These nanocarriers may enhance the solubility and permeability of drugs, increase their bioavailability, and extend the residence time in the body, combining low toxicity with a targeted delivery. Nanostructured lipid carriers are the second generation of lipid nanoparticles differing from solid lipid nanoparticles in their composition matrix. The use of a liquid lipid together with a solid lipid in nanostructured lipid carrier allows it to load a higher amount of drug, enhance drug release properties, and increase its stability. Therefore, a direct comparison between solid lipid nanoparticles and nanostructured lipid carriers is needed. This review aims to describe solid lipid nanoparticles and nanostructured lipid carriers as drug delivery systems, comparing both, while systematically elucidating their production methodologies, physicochemical characterization, and in vitro and in vivo performance. In addition, the toxicity concerns of these systems are focused on.