Percorrer por autor "Baptista-Silva, Sara"
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- Adenosine-loaded silk fibroin aerogel particles for wound healingPublication . Bernardes, Beatriz G.; Rossa, Valentina; Baptista-Silva, Sara; Magalhães, Rui; Costa, Raquel; García-González, Carlos A.; Oliveira, Ana LeiteChronic wounds are one of the major therapeutic and healthcare challenges. A natural healing response is the production of exudate from a wound. However, its overproduction can compromise and delay the inflammatory phase, resulting in chronicity. Bio-based aerogels, from natural polymer sources, can provide advanced performance for wound healing due to their high porosity and large surface area, which can be tailored for a fast and directional fluid transfer of the exudate; also, they can act as carriers for bioactive compounds. Silk fibroin (SF) protein is an excellent carrier of bioactive compounds while supporting cell proliferation, being presently used in wound healing and regeneration. In this work, we propose the use supercritical CO2 technology to develop SF aerogel particles as a controlled release system of adenosine, a protein that is herein proposed for the first time being expected to trigger the healing process of chronic wounds, promoting angiogenesis and regeneration. For the aerogel particles’ production, SF aqueous solutions at different concentrations (3, 5 and 7 %(w/v)) loaded with adenosine at different ratios were dispersed in a solution of ethanol/Span 80 (3 wt.% with respect to SF), followed by supercritical CO2 drying (120 bar, 39ºC, 3.5 h). Physico-chemical characteristics, drug release and cytotoxicity activity of bioactive SF particles will be explored.
- An uplifting avenue upon mealworm chitosan for hemodialysis applicationPublication . Martingo, Maria; Baptista-Silva, Sara; Mesquita, Raquel; Ferreira, João Paulo; Borges, Sandra; Pintado, ManuelaChronic kidney disease (CKD) is characterized by a continuous decline in kidney function, often persisting for years or even a lifetime. This study presents a new exploration into the extraction and application of insect chitosan (Tenebrio molitor) targeting hemodialysis (HD). Initially, the potential of insect-derived chitosan as a sustainable and effective alternative to traditional sources (i.e. crustaceans) is demonstrated. Efficient extraction methods were developed (totaling between 6 h and 12 h), producing chitosan. Firstly, chitin was efficiently isolated from T. molitor through deproteinization and demineralization, with yields of approximately 5% (w/w). Subsequently, chitosan was obtained from the extracted chitin resulting in yields of between 65.0 ± 0.8% (w/w) and 79.3 ± 0.8% (w/w). Characterization using Fourier Transform Infrared Spectroscopy (FTIR) confirmed structural similarities with commercial chitosan and degrees of deacetylation in the 73 - 75% range. The bioactive properties of chitosan obtained from T. molitor, including antimicrobial and antioxidant activities, were evaluated. All the microorganisms tested were inhibited, exhibiting minimum lethal concentrations between 2 and 8 mg/mL, confirming the antimicrobial activity of the extracted chitosan. In addition, chitosan showed antioxidant activity in the range of 60 to 65 µmol Trolox equivalent/g, suggesting its viability for various medical applications. This study also developed a chitosan-based membrane (CH - M) culminating in a proof-of-concept phase for hemodialysis. The permeation characteristics of CH-M for urea and albumin were studied in vitro to assess their suitability as HD membranes. Urea was permeable to values of over 70% and albumin was retained.
- Development of self-assembled aerogel silk particles for wound healingPublication . Bernardes, Beatriz G.; Baptista-Silva, Sara; Illanes-Bordomás, Carlos; Magalhães, Rui; Costa, Raquel; García-González, Carlos A.; Oliveira, Ana Leite
- Elevating skincare science: grape seed extract encapsulation for dermatological carePublication . Castro, Maria Leonor; Azevedo-Silva, João; Valente, Diana; Machado, Adriana; Ribeiro, Tânia; Ferreira, João Paulo; Pintado, Manuela; Ramos, Oscar L.; Borges, Sandra; Baptista-Silva, SaraThe skin is the largest organ in the human body and serves multiple functions such as barrier protection and thermoregulation. The maintenance of its integrity and healthy structure is of paramount importance. Accordingly, technological advances in cosmetic sciences have been directed towards optimizing these factors. Plant-derived ingredients have been explored for their bioactivity profiles and sustainable sources. Grape by-products contain a group of bioactive molecules that display important biological activities. Nonetheless, many of these molecules (e.g., phenolic compounds) are unstable and susceptible to degradation. So, their encapsulation using nano/microsystems (i.e., microdispersions) has been explored as a promising solution. In this work, two grape seed extracts were obtained, one from a single grape variety (GSE-Ov) and another from a mix of five grape varieties (GSE-Sv). These extracts were analysed for their antioxidant and antimicrobial activities, as well as their chemical composition and molecular structure. The extract that showed the most promising properties was GSE-Ov with a DPPH IC50 of 0.079 mg mL−1. This extract was encapsulated in soy lecithin microdispersions coated with pectin, with an encapsulation efficiency of 88.8%. They showed an in vitro release of polyphenols of 59.4% during 24 h. The particles displayed a zeta potential of −20.3 mV and an average diameter of 13.6 µm. Microdispersions proved to be safe under 5 and 2.5 mg mL−1 in HaCaT and HDF cell models, respectively. Additionally, they demonstrated anti-inflammatory activity against IL-1α when tested at 2 mg mL−1. This work enabled the valorisation of a by-product from the wine industry by using natural extracts in skincare products.
- Elevating skincare science: grape seed-extract encapsulation for dermatological carePublication . Castro, Maria Leonor de; Azevedo-Silva, João; Valente, Diana; Machado, Adriana; Ribeiro, Tânia; Ferreira, João Paulo; Pintado, Manuela; Ramos, Oscar L.; Baptista-Silva, SaraThe skin is the largest organ in the human body and serves multiple functions such as barrier protection and thermoregulation. The maintenance of its integrity and healthy structure is of paramount importance. Accordingly, technological advances in cosmetic sciences have been directed towards optimizing these factors. Plant-derived ingredients have been explored for their bioactivity profiles and sustainable sources. Grape by-products carry a group of bioactive molecules that display important biological activities. Nonetheless, many of these molecules (e.g., phenolic compounds) are unstable and susceptible to degradation. So, its encapsulation using nano/microsystems (i.e. liposomes) has been explored as a promising solution. In this work, two grape seed extracts were obtained, one from a single grape variety (GSE-Ov), and another from a mix of five grape varieties (GSE-Sv). These extracts were analysed for their antioxidant and antimicrobial activities, as well as for their chemical composition and molecular structure. The extract that showed the most promising properties was the GSE-Ov with a DPPH IC50 of 0.079 mg.mL-1. This extract was encapsulated in soy lecithin liposomes coated with pectin, with an encapsulation efficiency of 88.8%. These showed an in vitro release of polyphenols of 59.4% during 24 h. The particles displayed a zeta potential of -20.3 mV, and an average diameter of 13.6 ?m. Loaded liposomes proved to be safe under 5 and 2.5 mg.mL-1, in HaCaT and HDF cell models, respectively. Additionally, they demonstrated anti-inflammatory activity against IL-1? when tested at 2 mg.mL-1. This work enabled the valorization of a by-product from the wine industry, by using natural extracts in skincare products.
- Endowed polyphenols in advanced delivery systems for vaginal infectionsPublication . Apolinário, Eduardo; Castro, Maria Leonor; Pintado, Manuela; Ferreira, João Paulo; Baptista-Silva, Sara; Borges, SandraVaginal infections (VIs) are the result of the nefarious vaginal polymicrobial universe (i.e., Gardnerella vaginalis, Prevotella spp., Staphylococcus spp., Candida albicans, etc.), the inhabitants of which multiply and infect the surface of the vaginal epithelium, which serves as a scaffold for the adhesion of pathogenic poly-complexes with interactive abilities. VIs affect over 1 billion women per year and have a stunning annual relapse rate of 30%. These conditions impact women’s quality of life and fertility and cause oncogenic Human Papillomavirus (HPV) persistence. VIs are typically treated with oral (i.e., Flagyl®) and localized drug tablets and creams/gels (i.e., Clindesse®), with potential leakage from the vaginal tract upon administration leading to the failure of the treatment. This study intends to highlight polyphenols as potential therapeutic agents in terms of their benefits and limitations and suggest strategies to increase their effectiveness. Polyphenols are natural compounds rich in phenolic structures which have an impact on this type of pathology and deserve the utmost attention from researchers. Natural polyphenols have several advantages: renewability, biodegradability, low environmental impact, biocompatibility, application versatility, bioactive properties, and the potential for sustainable applications. These compounds, formulated in advanced delivery systems, may natively exhibit antioxidant, anti-inflammatory, and antimicrobial activities. The main objective of this review is to highlight the importance of researching new and effective formulations to prevent and treat VIs based on natural, controlled, and sustainable systems.
- Expanding the potential of self-assembled silk fibroin as aerogel particles for tissue regenerationPublication . Bernardes, Beatriz G.; Baptista-Silva, Sara; Illanes-Bordomás, Carlos; Magalhães, Rui; Dias, Juliana Rosa; Alves, Nuno M. F.; Costa, Raquel; García-González, Carlos A.; Oliveira, Ana LeiteA newly produced silk fibroin (SF) aerogel particulate system using a supercritical carbon dioxide (scCO2)-assisted drying technology is herein proposed for biomedical applications. Different concentrations of silk fibroin (3%, 5%, and 7% (w/v)) were explored to investigate the potential of this technology to produce size- and porosity-controlled particles. Laser diffraction, helium pycnometry, nitrogen adsorption–desorption analysis and Fourier Transform Infrared with Attenuated Total Reflectance (FTIR-ATR) spectroscopy were performed to characterize the physicochemical properties of the material. The enzymatic degradation profile of the SF aerogel particles was evaluated by immersion in protease XIV solution, and the biological properties by cell viability and cell proliferation assays. The obtained aerogel particles were mesoporous with high and concentration dependent specific surface area (203–326 m2/g). They displayed significant antioxidant activity and sustained degradation in the presence of protease XIV enzyme. The in vitro assessment using human dermal fibroblasts (HDF) confirm the particles’ biocompatibility, as well as the enhancement in cell viability and proliferation.
- Exploring silk Sericin for diabetic wounds: an in situ-forming hydrogel to protect against oxidative stress and improve tissue healing and regenerationPublication . Baptista-Silva, Sara; Bernardes, Beatriz G.; Borges, Sandra; Rodrigues, Ilda; Fernandes, Rui; Gomes-Guerreiro, Susana; Pinto, Marta Teixeira; Pintado, Manuela; Soares, Raquel; Costa, Raquel; Oliveira, Ana LeiteChronic wounds are one of the most frequent complications that are associated with diabetes mellitus. The overproduction of reactive oxygen species (ROS) is a key factor in the delayed healing of a chronic wound. In the present work, we develop a novel in situ-forming silk sericin-based hydrogel (SSH) that is produced by a simple methodology using horseradish peroxidase (HRP) crosslinking as an advanced dressing for wound healing. The antioxidant and angiogenic effects were assessed in vitro and in vivo after in situ application using an excisional wound-healing model in a genetically-induced diabetic db/db mice and though the chick embryo choriollantoic membrane (CAM) assay, respectively. Wounds in diabetic db/db mice that were treated with SSH closed with reduced granulation tissue, decreased wound edge distance, and wound thickness, when compared to Tegaderm, a dressing that is commonly used in the clinic. The hydrogel also promoted a deposition of collagen fibers with smaller diameter which may have had a boost effect in re-epithelialization. SSH treatment slightly induced two important endogenous antioxidant defenses, superoxide dismutase and catalase. A CAM assay made it possible to observe that SSH led to an increase in the number of newly formed vessels without inducing an inflammatory reaction. The present hydrogel may result in a multi-purpose technology with angiogenic, antioxidant, and anti-inflammatory properties, while advancing efficient and organized tissue regeneration.
- Exploring the potential of mealworm chitosan for hemodialysis applicationsPublication . Martingo, Maria; Baptista-Silva, Sara; Mesquita, Raquel; Ferreira, João Paulo; Borges, Sandra; Pintado, ManuelaThis study introduces a sustainable and efficient alternative to traditional chitosan sources derived from crustaceans, exploring the extraction and application of insect-derived chitosan from Tenebrio molitor for hemodialysis (HD) membranes design. Efficient extraction and deacetylation methods were tested and developed between 6 h and 12 h to obtain chitosan. Chitin was isolated from T. molitor through deproteinization and demineralization, with yields of approximately 5 % (w/w). Chitosan was obtained from the extracted chitin resulting in yields of between 65.0 and 79.3 (w/w). Characterization using FTIR confirmed structural similarities with commercial chitosan and degrees of deacetylation in the 73–75 % range. The bioactive properties of chitosan obtained from T. molitor, including antimicrobial and antioxidant activities, were evaluated. All the microorganisms tested were inhibited, exhibiting minimum lethal concentrations between 2 and 8 mg/mL. In addition, chitosan showed antioxidant activity in the range of 60–65 μmol Trolox equivalent/g, suggesting its viability for various medical applications. This study additionally allowed the design of sustainable hybrid chitosan membrane (CH-M) tailored for HD applications. The permeation characteristics of CH-M for urea and albumin were studied in vitro to assess their suitability as HD membranes. Urea was permeable to values of over 70 % and albumin was retained. Also, cytotoxicity assays against L929 fibroblast cells demonstrated that the CH-M samples exhibit low metabolic inhibition (around 15 %) The application of CH-M in HD represents a significant advance, offering the potential for enhanced therapeutic outcomes for chronic kidney disease (CKD).
- Fucoidans: exploring its neuroprotective mechanisms and therapeutic applications in brain disordersPublication . Batista, Patrícia; Cunha, Sara A.; Ribeiro, Tânia; Borges, Sandra; Baptista-Silva, Sara; Oliveira-Silva, Patrícia; Pintado, ManuelaBackground: Marine-derived natural products have been attracting attention from both the food and pharmaceutical sectors due to their promising therapeutic attributes. Algae and their biomolecules are examples of marine-derived products for ongoing research endeavors. Fucoidan, an algae-derived polysaccharide, has emerged as a recent biomolecule related to a diverse array of beneficial properties, with particular emphasis on its neuroprotective activities. Scope and approach: This review intended to understand the neuroprotective properties of Fucoidan and its impact on brain disorders. Fucoidan has risen to prominence as one of the most promising neuroprotective agents obtained from macroalgae, with in vitro and in vivo studies proving its efficiency. Nevertheless, the extant literature underscores the imperative for further clinical trials to substantiate its therapeutic prowess. The neuroprotective effect of fucoidan is related to oxidative stress, mitochondrial function, neuroinflammation, apoptosis, as well as the interaction between gut-brain-microbiota. Key findings and conclusions: Despite having numerous health benefits being approved by regulatory entities, fucoidan products consumption, and use by industry still needs to be explored. Henceforth, there is a need to search for an efficient method for the successful commercialization of fucoidan, focusing on its suitable dosage for pharmaceutical and nutraceutical applications, but it is also necessary to have clinical studies proving its efficacy in brain disorders. Therefore, this biomolecule has the potential to be exploited by researchers, investors and consumers. In this way, fucoidan could contribute to the promotion and improvement of society’s quality of life concerning specific brain pathologies.
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