Percorrer por autor "Fonte, Pedro"
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- Formulation of poly(butylene adipate-co-terephthalate)/caffeic acid composites for vegetable packaging applicationsPublication . Sana, Siva Sankar; Riahi, Zohreh; Mishra, Vijayalaxmi; Kim, Jun Tae; Vadde, Ramakrishna; Brandão, Pedro; Kim, Seong-Cheol; Fonte, PedroPoly(butylene adipate-co-terephthalate) (PBAT) is widely used as a bioplastic owing to its commendable water-barrier properties. In this work, PBAT was blended with caffeic acid (CA) (1–3 wt%) by solution mixing using chloroform as a solvent through solvent casting method. UV–Visible spectroscopy results show a decrease in transmittance from 100 % in PBAT to 6 % PBAT/3CA. The film's elongation was notably improved with an increase in the CA ratio, reaching up to 1055.4 %. Moreover, the tensile strength experienced a significant enhancement upon the inclusion of CA (3 wt%) up to 25.5 MPa. The decrease in water vapor permeability (WVP) (3.05 ± 0.1 × 10−11 g.m/m2.Pa.s) and water contact angle (WCA) (60.5° ± 1.34°) was observed in PBAT/3CA. PBAT film containing 3 wt% CA exhibited remarkable scavenging action against ABTS•+ and DPPH•, recording values of 100 % and 98.5 %, respectively. When subjected to testing against foodborne pathogens such as Escherichia coli (E. coli) and Listeria monocytogenes (L. monocytogenes), the fabricated films displayed excellent antibacterial activity. The active films comprising PBAT/CA possess the potential to serve as a synergistic solution for food packaging, combining the UV barrier property, mechanical properties, flexibility, peeling resistance, and renowned biodegradability of PBAT with the ability to repurpose industrial waste.
- Gestão e seguimento do doente com DPOCPublication . Fonte, Pedro
- 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; Costa, Joyce Maria Gomes da; Schmiele, Marcio; Silveira, João Vinícios Wirbitzki da; 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 °Brix, 14.40 °Brix, 11.33 °Brix, respectively). Thus, for the analyses conducted, the cryoprotectants did not lead to significant advantages for this process.
- Inhalable N-acetylcysteine-loaded lactose-coated PLGA nanoparticles for tuberculosis treatmentPublication . Chaudhary, Kabi Raj; Viegas, Cláudia; Pirela, Paola; Atalaia, Mariana; Ruivinho, Beatriz; Arora, Sanchit; Singh, Arti; Brandão, Pedro; Singh, Charan; Fonte, PedroObjective: Glutathione (GSH), known for having mucolytic, anti-inflammatory, and antioxidant activities, is used in clinical practice in several pathologies, including tuberculosis (TB). N-acetylcysteine (NAC) has been primarily used to treat lung conditions and paracetamol-induced liver toxicity. However, NAC exhibits potential antimycobacterial activity through several mechanisms including immunomodulation, enhancement of GSH levels, and direct antimycobacterial effect. In this work, we aim to develop an effective drug delivery system for NAC for inhalable formulations. Methods: Herein, we report the development of lactose-coated NAC-loaded Poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NAC-PLGA NPs) obtained by double emulsion methodology. Lactose has a double role, as a cryoprotectant agent and dispersant for inhalable formulations. The physicochemical properties of lactose-coated NAC-PLGA NPs were examined in terms of particle size, polydispersity index (PdI), zeta potential (ZP), encapsulation efficiency, and morphology. The in vitro release and lung deposition studies were assessed. Results: The physicochemical characterization studies revealed the compatibility of the drug with the selected excipients. Moreover, lactose-coated NAC-PLGA NPs showed particle size of 310 ± 3 nm, PdI of 0.15 ± 0.01, and of -11.5 ± 0.4 mV. The in vitro release study suggested a biphasic release profile. Likewise, in vitro lung deposition studies revealed desirable lung deposition parameters, indicating effective particle size for efficient pulmonary delivery. Additionally, in vitro studies for antimycobacterial activity exhibited superior antibacterial activity against Mycobacterium Tuberculosis (MTB) H37Rv. Conclusions: These preliminary findings suggest that lactose-coated NAC-PLGA NPs can open the door to new therapeutic options against one of the most drug-refractory and drug-resistant infectious diseases, TB.
- Lipid-based nanoformulations for drug delivery : an ongoing perspectivePublication . Rehman, Mubashar; Tahir, Nayab; Sohail, Muhammad Farhan; Qadri, Muhammad Usman; Duarte, Sofia O. D.; Brandâo, Pedro; Esteves, Teresa; Javed, Ibrahim; Fonte, PedroOils and lipids help make water-insoluble drugs soluble by dispersing them in an aqueous medium with the help of a surfactant and enabling their absorption across the gut barrier. The emergence of microemulsions (thermodynamically stable), nanoemulsions (kinetically stable), and self-emulsifying drug delivery systems added unique characteristics that make them suitable for prolonged storage and controlled release. In the 1990s, solid-phase lipids were introduced to reduce drug leakage from nanoparticles and prolong drug release. Manipulating the structure of emulsions and solid lipid nanoparticles has enabled multifunctional nanoparticles and the loading of therapeutic macromolecules such as proteins, nucleic acid, vaccines, etc. Phospholipids and surfactants with a well-defined polar head and carbon chain have been used to prepare bilayer vesicles known as liposomes and niosomes, respectively. The increasing knowledge of targeting ligands and external factors to gain control over pharmacokinetics and the ever-increasing number of synthetic lipids are expected to make lipid nanoparticles and vesicular systems a preferred choice for the encapsulation and targeted delivery of therapeutic agents. This review discusses different lipids and oil-based nanoparticulate systems for the delivery of water-insoluble drugs. The salient features of each system are highlighted, and special emphasis is given to studies that compare them.
- Nanocarriers in Tuberculosis treatment : challenges and delivery strategiesPublication . Kumar, Mahesh; Virmani, Tarun; Kumar, Girish; Deshmukh, Rohitas; Sharma, Ashwani; Duarte, Sofia; Brandão, Pedro; Fonte, PedroThe World Health Organization identifies tuberculosis (TB), caused by Mycobacterium tuberculosis, as a leading infectious killer. Although conventional treatments for TB exist, they come with challenges such as a heavy pill regimen, prolonged treatment duration, and a strict schedule, leading to multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains. The rise of MDR strains endangers future TB control. Despite these concerns, the hunt for an efficient treatment continues. One breakthrough has been the use of nanotechnology in medicines, presenting a novel approach for TB treatment. Nanocarriers, such as lipid nanoparticles, nanosuspensions, liposomes, and polymeric micelles, facilitate targeted delivery of anti-TB drugs. The benefits of nanocarriers include reduced drug doses, fewer side effects, improved drug solubility, better bioavailability, and improved patient compliance, speeding up recovery. Additionally, nanocarriers can be made even more targeted by linking them with ligands such as mannose or hyaluronic acid. This review explores these innovative TB treatments, including studies on nanocarriers containing anti-TB drugs and related patents.
- Sustainable carbon dots loaded into carboxymethylcellulose based hydrogels for uterine cancer bioimagingPublication . Rodrigues, Jordane S.; Brandão, Pedro; Duarte, Sofia O. D.; Silveira, Izabela Boueri da; Leite, Maria de Fátima; Gonçalves, Max. P.; Borsagli, Fernanda G. L. Medeiros; Fonte, PedroBackground/Objectives: The development of innovative materials for disease diagnostics and therapeutics is a fast-growing area of scientific research. In this work, we report the development of innovative hydrogels incorporating carbon dots (Cdots) for bioimaging purposes. Methods: The Cdots were prepared using a sustainable and low-cost process, starting with an underused fiber from the Brazilian semiarid region. Spectroscopy analysis (Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, UV-visible spectroscopy), X-ray diffraction, photoluminescence, zeta potential, scanning electron microscopy, and transmission electron microscopy were used to characterize these hydrogels. In addition, biocompatibility using the resazurin assay and cellular uptake by confocal microscopy were evaluated. Results: Our results showed that the Cdots changed the structure and crystallinity of hydrogels, mainly due to heat treatment. In addition, hydrogels’ chemical groups suffer red and blue shifts following the Cdots incorporation. Moreover, the Cdots were homogeneously incorporated into the hydrogel matrix. Importantly, the cytotoxicity levels were maintained above 90% (p < 0.01), and cellular uptake studies using HeLa cells demonstrated intracellular fluorescence of both the Cdots and hydrogels after incubation. Additionally, the concentration of Cdots within hydrogels significantly affected fluorescence intensity, even compared with pure Cdots. Conclusions: These results showcase the potential for these hydrogels to be further developed as biomarkers and therapeutic biomaterials for women’s health.
- Vacinação do doente com DPOCPublication . Fonte, Pedro