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1.
Polymers (Basel) ; 16(5)2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38475324

RESUMO

In recent years, there has been a growing interest in developing smart drug delivery systems based on natural resources combined with stimulus-sensitive elements. This trend aims to formulate innovative and sustainable delivery platforms tailored for topical applications. This work proposed the use of layer-by-layer (LbL) methodology to fabricate biocompatible photo-responsive multilayer systems. These systems are composed of a polyoxometalate inorganic salt (POM) ([NaP5W30O110]14-) and a natural origin polymer, chitosan (CHT). Curcumin (CUR), a natural bioactive compound, was incorporated to enhance the functionality of these systems during the formation of hollow capsules. The capsules produced, with sizes between 2-5µm (SEM), were further dispersed into CHT/VCO (virgin coconut oil) emulsion solutions that were casted into molds and dried at 37 °C for 48 h. The system presented a higher water uptake in PBS than in acidic conditions, still significantly lower than that earlier reported to other CHT/VCO-based systems. The drug release profile is not significantly influenced by the medium pH reaching a maximum of 37% ± 1% after 48 h. The antioxidant performance of the designed structures was further studied, suggesting a synergistic beneficial effect resulting from CUR, POM, and VCO individual bioactivities. The increased amount of those excipients released to the media over time promoted an increase in the antioxidant activity of the system, reaching a maximum of 38.1% ± 0.1% after 48 h. This work represents a promising step towards developing advanced, sustainable drug delivery systems for topical applications.

2.
Bragança; s.n; 20240000. tab..
Tese em Português | BDENF - Enfermagem | ID: biblio-1527240

RESUMO

As infeções do trato urinário associadas ao cateter vesical são uma realidade constante, associada aos cuidados de saúde, sendo a causa principal da morbilidade, prolongamento do período de internamento e dos custos relacionados. A norma da Direção Geral de Saúde: "Feixe de Intervenções para a Prevenção da Infeção Urinária Associada Ao Cateter Vesical" surge no sentido de uniformizar as intervenções de Enfermagem. Este estudo tem como objetivo analisar o conhecimento dos enfermeiros sobre o Feixe de Intervenções de Prevenção de Infeção Urinária Associada a Cateter Vesical numa unidade local de saúde do norte de Portugal. Metodologia: Estudo transversal analítico, realizado em 103 enfermeiros numa população de 731 de uma Unidade Local de Saúde do Norte de Portugal. Os critérios de inclusão: Enfermeiros que estão diretamente na prestação de cuidados. O instrumento de recolha de dados foi um questionário, via Google Forms, constituído por duas partes: a primeira com questões sobre a caraterização sociodemográfica e profissional e a segunda sobre as intervenções de enfermagem em relação ao Feixe de Intervenções de Prevenção de Infeção Urinária Associada a Cateter Vesical. Para a recolha de dados foi solicitado ao enfermeiro diretor o envio do link do IRD aos enfermeiros gestores e por sua vez estes a cada elemento da sua equipa. O estudo obteve o parecer favorável da Comissão de Ética n.º 5/2023. Resultados: O conhecimento dos enfermeiros no geral revela-se moderado (74,8%). Há maior predomínio no sexo feminino (86,4%), idade entre os 36 e 40 anos, casados (58,3%), licenciatura (74,8%), enfermeiros generalistas (63,1%), contrato individual de trabalho sem termo (62,1%), tempo de serviço médio 41,66 ± 7,61 anos, hospital como local de trabalho (87,4%), horário por turnos (85,4%), formação sobre a prevenção da IUACV (69,9%) e conhecimento da existência de norma sobre a prevenção da IUACV (92,2%). Verificou-se relação, estatisticamente significativa, entre o conhecimento do feixe e a formação. O sexo feminino apresenta mais conhecimento no Elemento "Cumprir técnica assética no procedimento de cateterização vesical e conexão ao sistema de drenagem", e os enfermeiros especialistas mostram mais conhecimento no elemento "Manter o CV seguro com o saco coletor abaixo do nível da bexiga…". Os enfermeiros com formação apresentam um conhecimento global superior e mostram mais conhecimento no Elemento "Cumprir técnica assética no procedimento de CV e conexão ao sistema de drenagem" e "Avaliar diariamente a possibilidade de remover o CV, retirando-o logo que possível…" Conclusão: O conhecimento dos enfermeiros é moderado. A formação associou-se com o conhecimento; o sexo e a categoria profissional associaram-se com alguns elementos do feixe. Sugere-se implementação de "Bundles" para uniformizar intervenções, a promoção de formação continua e académica e a realização de outros estudos.


Urinary tract infections associated with bladder catheters are a constant reality associated with healthcare, and are the main cause of morbidity, prolonged hospitalization and related costs. The General Directorate of Health's standard: "Interventions for the Prevention of Bladder Catheter-Associated Urinary Tract Infection", aims to standardize nursing interventions. The aim of this study was to analyze nurses' knowledge of the Bundle of Interventions for the Prevention of Bladder Catheter-Associated Urinary Tract Infection in a local health unit in northern Portugal. Methodology: Analytical cross-sectional study carried out on 103 nurses in a population of 731 from a Local Health Unit in the north of Portugal. Inclusion criteria: Nurses directly involved in the provision of care. The data collection instrument was a questionnaire, via Google Forms, consisting of two parts: the first with questions on sociodemographic and professional characterization and the second on nursing interventions in relation to the Bundle of Interventions for the Prevention of Bladder Catheter-Associated Urinary Tract Infection. To collect the data, the nurse manager was asked to send the IRD link to the nurse managers, who in turn sent it to each member of their team. The study received a favorable opinion from the Ethics Committee No. 5/2023. Results: Nurses' knowledge overall is shown to be moderate (74.8%). There was a greater predominance of females (86.4%), average age between 36 and 40 years, married (58.3%), university degree (74.8%), generalist nurses (63.1%), individual employment contract without term (62.1%), average length of service 41, 66±7.61 years, hospital as place of work (87.4%), shift work (85.4%), training in the prevention of IUACV (69.9%) and knowledge of the existence of regulations on the prevention of IUACV (92.2%). There was a statistically significant relationship between knowledge of the beam and training. Females showed more knowledge in the element "Comply with aseptic technique in the bladder catheterization procedure and connection to the drainage system", and specialist nurses showed more knowledge in the element "Keep the CV secure with the collection bag below the level of the bladder...". Trained nurses have a higher overall knowledge and show more knowledge in the Element "Comply with aseptic technique in the CV procedure and connection to the drainage system" and "Evaluate daily the possibility of removing the CV, removing it as soon as possible...". Conclusion: Nurses' knowledge is moderate. Training was associated with knowledge, gender and professional category were associated with some elements of the bundle. It is suggested that "Bundles" be implemented to standardize interventions, that continuing and academic training be promoted and that further studies be carried out.


Assuntos
Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Infecções Urinárias , Cateteres Urinários , Cuidados de Enfermagem
3.
Biomater Adv ; 156: 213712, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38056110

RESUMO

Selective COX-2 inhibitors such as etoricoxib (ETX) are potentially indicated for the treatment of intestinal inflammatory disorders. However, their systemic administration provokes some off-site secondary effects, decreasing the desirable local effectiveness. To circumvent such limitations, herein an ETX delivery system based on electrospun fibrous meshes (eFMs) was proposed. ETX at different concentrations (1, 2, and 3 mg mL-1) was loaded into eFMs, which not affect the morphology and the mechanical properties of this drug delivery system (DDS). The ETX showed a burst release within the first 12 h, followed by a faster release until 36 h, gradually decreasing over time. Importantly, the ETX studied concentrations were not toxic to human colonic cells (i.e. epithelial and fibroblast). Moreover, the DDS loading the highest concentration of ETX, when tested with stimulated human macrophages, promoted a reduction of PGE2, IL-8 and TNF-α secretion. Therefore, the proposed DDS may constitute a safe and efficient treatment of colorectal diseases promoted by inflammatory disorders associated with COX-2.


Assuntos
Inibidores de Ciclo-Oxigenase 2 , Sistemas de Liberação de Medicamentos , Doenças Inflamatórias Intestinais , Humanos , Ciclo-Oxigenase 2 , Inibidores de Ciclo-Oxigenase 2/administração & dosagem , Inibidores de Ciclo-Oxigenase 2/farmacologia , Dinoprostona , Etoricoxib/administração & dosagem , Etoricoxib/farmacologia , Fator de Necrose Tumoral alfa , Doenças Inflamatórias Intestinais/tratamento farmacológico
4.
Acta Biomater ; 173: 298-313, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37979636

RESUMO

3D bioprinting enables the fabrication of biomimetic cell-laden constructs for cartilage regeneration, offering exclusive strategies for precise pharmacological screenings in osteoarthritis (OA). Synovial inflammation plays a crucial role in OA's early stage and progression, characterized by the increased of the synovial pro-inflammatory mediators and cytokines and chondrocyte apoptosis. Therefore, there is an urgent need to develop solutions for effectively managing the primary events associated with OA. To address these issues, a phenolic-based biocompatible ionic liquid approach, combining alginate (ALG), acemannan (ACE), and cholinium caffeate (Ch[Caffeate]), was used to produce easily printable bioinks. Through the use of this strategy 3D constructs with good printing resolution and high structural integrity were obtained. The encapsulation of chondrocytes like ATDC5 cells provided structures with good cell distribution, viability, and growth, for up to 14 days. The co-culture of the constructs with THP-1 macrophages proved their ability to block pro-inflammatory cytokines (TNF-α and IL-6) and mediators (GM-CSF), released by the cultured cells. Moreover, incorporating the biocompatible ionic liquid into the system significantly improved its bioactive performance without compromising its physicochemical features. These findings demonstrate that ALG/ACE/Ch[Caffeate] bioinks have great potential for bioengineering cartilage tissue analogs. Besides, the developed ALG/ACE/Ch[Caffeate] bioinks protected encapsulated chondrocyte-like cells from the effect of the inflammation, assessed by a co-culture system with THP-1 macrophages. These results support the increasing use of Bio-ILs in the biomedical field, particularly for developing 3D bioprinting-based constructs to manage inflammatory-based changes in OA. STATEMENT OF SIGNIFICANCE: Combining natural resources with active biocompatible ionic liquids (Bio-IL) for 3D printing is herein presented as an approach for the development of tools to manage inflammatory osteoarthritis (OA). We propose combining alginate (ALG), acemannan (ACE), and cholinium caffeate (Ch[Caffeate]), a phenolic-based Bio-IL with anti-inflammatory and antioxidant features, to produce bioinks that allow to obtain 3D constructs with good printing resolution, structural integrity, and that provide encapsulated chondrocyte-like cells good viability. The establishment of a co-culture system using the printed constructs and THP-1-activated macrophages allowed us to study the encapsulated chondrocyte-like cells behaviour within an inflammatory scenario, a typical event in early-stage OA. The obtained outcomes support the beneficial use of Bio-ILs in the biomedical field, particularly for the development of 3D bioprinting-based models that allow the monitoring of inflammatory-based events in OA.


Assuntos
Bioimpressão , Líquidos Iônicos , Osteoartrite , Humanos , Líquidos Iônicos/farmacologia , Citocinas , Osteoartrite/tratamento farmacológico , Inflamação , Anti-Inflamatórios/farmacologia , Alginatos/farmacologia , Alginatos/química , Impressão Tridimensional , Engenharia Tecidual/métodos , Bioimpressão/métodos , Alicerces Teciduais/química
5.
Mar Drugs ; 21(7)2023 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-37504925

RESUMO

Emulsion-based systems that combine natural polymers with vegetable oils have been identified as a promising research avenue for developing structures with potential for biomedical applications. Herein, chitosan (CHT), a natural polymer, and virgin coconut oil (VCO), a resource obtained from coconut kernels, were combined to create an emulsion system. Phytantriol-based cubosomes encapsulating sodium diclofenac, an anti-inflammatory drug, were further dispersed into CHT/VCO- based emulsion. Then, the emulsions were frozen and freeze-dried to produce scaffolds. The scaffolds had a porous structure ranging from 20.4 to 73.4 µm, a high swelling ability (up to 900%) in PBS, and adequate stiffness, notably in the presence of cubosomes. Moreover, a well-sustained release of the entrapped diclofenac in the cubosomes into the CHT/VCO-based system, with an accumulated release of 45 ± 2%, was confirmed in PBS, compared to free diclofenac dispersed (80 ± 4%) into CHT/VCO-based structures. Overall, the present approach opens up new avenues for designing porous biomaterials for drug delivery through a sustainable pathway.


Assuntos
Quitosana , Emulsões , Diclofenaco , Óleos de Plantas/química , Óleo de Coco/química
6.
Molecules ; 28(11)2023 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-37298999

RESUMO

Current management for diabetes has stimulated the development of versatile 3D-based hydrogels as in vitro platforms for insulin release and as support for the encapsulation of pancreatic cells and islets of Langerhans. This work aimed to create agarose/fucoidan hydrogels to encapsulate pancreatic cells as a potential biomaterial for diabetes therapeutics. The hydrogels were produced by combining fucoidan (Fu) and agarose (Aga), marine polysaccharides derived from the cell wall of brown and red seaweeds, respectively, and a thermal gelation process. The agarose/fucoidan (AgaFu) blended hydrogels were obtained by dissolving Aga in 3 or 5 wt % Fu aqueous solutions to obtain different proportions (4:10; 5:10, and 7:10 wt). The rheological tests on hydrogels revealed a non-Newtonian and viscoelastic behavior, while the characterization confirmed the presence of the two polymers in the structure of the hydrogels. In addition, the mechanical behavior showed that increasing Aga concentrations resulted in hydrogels with higher Young's modulus. Further, the ability of the developed materials to sustain the viability of human pancreatic cells was assessed by encapsulation of the 1.1B4HP cell line for up to 7 days. The biological assessment of the hydrogels revealed that cultured pancreatic beta cells tended to self-organize and form pseudo-islets during the period studied.


Assuntos
Diabetes Mellitus , Hidrogéis , Humanos , Sefarose/química , Hidrogéis/farmacologia , Hidrogéis/química , Polissacarídeos/farmacologia , Polissacarídeos/química , Diabetes Mellitus/tratamento farmacológico
7.
Int J Biol Macromol ; 242(Pt 3): 125026, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37244345

RESUMO

Combining biomacromolecules with green chemistry principles and clean technologies has proven to be an effective approach for drug delivery, providing a prolonged and sustained release of the encapsulated material. The current study investigates the potential of cholinium caffeate (Ch[Caffeate]), a phenolic-based biocompatible ionic liquid (Bio-IL) entrapped in alginate/acemannan beads, as a drug delivery system able to reduce local joint inflammation on osteoarthritis (OA) treatment. The synthesized Bio-IL has antioxidant and anti-inflammatory actions that, combined with biopolymers as 3D architectures, promote the entrapment and sustainable release of the bioactive molecules over time. The physicochemical and morphological characterization of the beads (ALC, ALAC0,5, ALAC1, and ALAC3, containing 0, 0.5, 1, and 3 %(w/v) of Ch[Caffeate], respectively) revealed a porous and interconnected structure, with medium pore sizes ranging from 209.16 to 221.30 µm, with a high swelling ability (up 2400 %). Ch[Caffeate] significantly improved the antioxidant activities of the constructs by 95 % and 97 % for ALAC1 and ALAC3, respectively, when compared to ALA (56 %). Besides, the structures provided the environment for ATDC5 cell proliferation, and cartilage-like ECM formation, supported by the increased GAGs in ALAC1 and ALAC3 formulations after 21 days. Further, the ability to block the secretion of pro-inflammatory cytokines (TNF-α and IL-6), from differentiated THP-1 was evidenced by ChAL-Ch[Caffeate] beads. These outcomes suggest that the established strategy based on using natural and bioactive macromolecules to develop 3D constructs has great potential to be used as therapeutic tools for patients with OA.


Assuntos
Líquidos Iônicos , Humanos , Antioxidantes/farmacologia , Alginatos/química , Sistemas de Liberação de Medicamentos
8.
Gels ; 9(3)2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-36975696

RESUMO

The self-repair capacity of human tissue is limited, motivating the arising of tissue engineering (TE) in building temporary scaffolds that envisage the regeneration of human tissues, including articular cartilage. However, despite the large number of preclinical data available, current therapies are not yet capable of fully restoring the entire healthy structure and function on this tissue when significantly damaged. For this reason, new biomaterial approaches are needed, and the present work proposes the development and characterization of innovative polymeric membranes formed by blending marine origin polymers, in a chemical free cross-linking approach, as biomaterials for tissue regeneration. The results confirmed the production of polyelectrolyte complexes molded as membranes, with structural stability resulting from natural intermolecular interactions between the marine biopolymers collagen, chitosan and fucoidan. Furthermore, the polymeric membranes presented adequate swelling ability without compromising cohesiveness (between 300 and 600%), appropriate surface properties, revealing mechanical properties similar to native articular cartilage. From the different formulations studied, the ones performing better were the ones produced with 3 % shark collagen, 3% chitosan and 10% fucoidan, as well as with 5% jellyfish collagen, 3% shark collagen, 3% chitosan and 10% fucoidan. Overall, the novel marine polymeric membranes demonstrated to have promising chemical, and physical properties for tissue engineering approaches, namely as thin biomaterial that can be applied over the damaged articular cartilage aiming its regeneration.

9.
Pharmaceuticals (Basel) ; 15(6)2022 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35745671

RESUMO

The initial discovery phase of protein modulators, which consists of filtering molecular libraries and in vitro direct binding validation, is central in drug discovery. Thus, virtual screening of large molecular libraries, together with the evaluation of binding affinity by isothermal calorimetry, generates an efficient experimental setup. Herein, we applied virtual screening for discovering small molecule inhibitors of MDM2, a major negative regulator of the tumor suppressor p53, and thus a promising therapeutic target. A library of 20 million small molecules was screened against an averaged model derived from multiple structural conformations of MDM2 based on published structures. Selected molecules originating from the computational filtering were tested in vitro for their direct binding to MDM2 via isothermal titration calorimetry. Three new molecules, representing distinct chemical scaffolds, showed binding to MDM2. These were further evaluated by exploring structure-similar chemical analogues. Two scaffolds were further evaluated by de novo synthesis of molecules derived from the initial molecules that bound MDM2, one with a central oxoazetidine acetamide and one with benzene sulfonamide. Several molecules derived from these scaffolds increased wild-type p53 activity in MCF7 cancer cells. These set a basis for further chemical optimization and the development of new chemical entities as anticancer drugs.

10.
Polymers (Basel) ; 14(12)2022 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-35746048

RESUMO

Oleogels are becoming an attractive research field, since they have recently been shown to be feasible for the food and pharmaceutical sectors and provided some insights into the biomedical area. In this work, edible oleogels were tailored through the combination of ethylcellulose (EC), a gelling agent, with virgin coconut oil (VCO), vegetable oil derived from coconut. The influence of the different EC and VCO ratios on the structural, physical, and thermal properties of the oleogels was studied. All EC/VCO-based oleogels presented a stable network with a viscoelastic nature, adequate structural stability, modulable stiffness, high oil-binding capability, antioxidant activity, and good thermal stability, evidencing the EC and VCO's good compatibility.

11.
Biomacromolecules ; 23(6): 2415-2427, 2022 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-35623028

RESUMO

Metronidazole (MTZ) is a drug potentially used for the treatment of intestinal infections, namely, the ones caused by colorectal surgery. The traditional routes of administration decrease its local effectiveness and present off-site effects. To circumvent such limitations, herein a drug delivery system (DDS) based on MTZ-loaded nanoparticles (NPs) immobilized at the surface of electrospun fibrous meshes is proposed. MTZ at different concentrations (1, 2, 5, and 10 mg mL-1) was loaded into chitosan-sodium tripolyphosphate NPs. The MTZ loaded into NPs at the highest concentration showed a quick release in the first 12 h, followed by a gradual release. This DDS was not toxic to human colonic cells. When tested against different bacterial strains, a significant reduction of Escherichia coli and Staphylococcus aureus was observed, but no effect was found against Enterococcus faecalis. Therefore, this DDS offers high potential to locally prevent the occurrence of infections after colorectal anastomosis.


Assuntos
Quitosana , Neoplasias Colorretais , Nanopartículas , Antibacterianos/farmacologia , Bactérias , Quitosana/farmacologia , Sistemas de Liberação de Medicamentos , Escherichia coli , Humanos , Metronidazol/farmacologia , Virulência
12.
Materials (Basel) ; 15(5)2022 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-35268903

RESUMO

Bacterial colonization of polyurethane (PU) ureteral stents usually leads to severe and challenging clinical complications. As such, there is an increasing demand for an effective response to this unmet medical challenge. In this study, we offer a strategy based on the functionalization of PU stents with chitosan-fatty acid (CS-FA) derivatives to prevent bacterial colonization. Three different fatty acids (FAs), namely stearic acid (SA), oleic acid (OA), and linoleic acid (LinA), were successfully grafted onto chitosan (CS) polymeric chains. Afterwards, CS-FA derivatives-based solutions were coated on the surface of PU stents. The biological performance of the modified PU stents was evaluated against the L929 cell line, confirming negligible cytotoxicity of the developed coating formulations. The antibacterial potential of coated PU stents was also evaluated against several microorganisms. The obtained data indicate that the base material already presents an adequate performance against Staphylococcus aureus, which slightly improved with the coating. However, the performance of the PU stents against Gram-negative bacteria was markedly increased with the surface functionalization approach herein used. As a result, this study reveals the potential use of CS-FA derivatives for surface functionalization of ureteral PU stents and allows for conjecture on its successful application in other biomedical devices.

13.
Biomed Mater ; 17(1)2021 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-34785622

RESUMO

Bone regeneration and natural repair are long-standing processes that can lead to uneven new tissue growth. By introducing scaffolds that can be autografts and/or allografts, tissue engineering provides new approaches to manage the major burdens involved in this process. Polymeric scaffolds allow the incorporation of bioactive agents that improve their biological and mechanical performance, making them suitable materials for bone regeneration solutions. The present work aimed to create chitosan/beta-tricalcium phosphate-based scaffolds coated with silk fibroin and evaluate their potential for bone tissue engineering. Results showed that the obtained scaffolds have porosities up to 86%, interconnectivity up to 96%, pore sizes in the range of 60-170 µm, and a stiffness ranging from 1 to 2 MPa. Furthermore, when cultured with MC3T3 cells, the scaffolds were able to form apatite crystals after 21 d; and they were able to support cell growth and proliferation up to 14 d of culture. Besides, cellular proliferation was higher on the scaffolds coated with silk. These outcomes further demonstrate that the developed structures are suitable candidates to enhance bone tissue engineering.


Assuntos
Quitosana , Fibroínas , Fosfatos de Cálcio , Proliferação de Células , Fibroínas/química , Porosidade , Seda/química , Engenharia Tecidual/métodos , Alicerces Teciduais/química
14.
Carbohydr Polym ; 257: 117601, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33541636

RESUMO

The exploitation of natural origin macromolecules, as complex physical mixtures or drugs, increases in biomedical or tissue engineering (TE) solutions. Aloe Vera is a highly explored medicinal plant, from which the main polysaccharide is acemannan (ACE). The ACE combination with chitosan and alginate results in interactions that lead to mixed junction zones formation, predicting membrane functionality improvement. This work proposes the development and characterization of ACE-based blended films as a promising strategy to design a nature-derived bioactive platform. The results confirmed that stable complex polyelectrolyte structures were formed through different intermolecular interactions. The films present good dimensional stability, flexibility, an adequate swelling ability with mostly radial water uptake, and a sustainable ACE release to the medium. Positive biological performance of the ACE-based blended films with L929 cells also suggested that they can be applied in TE solutions, with the potential to act as bioactive topical platforms.


Assuntos
Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Mananas/química , Teste de Materiais , Alginatos/química , Aloe/química , Animais , Varredura Diferencial de Calorimetria , Quitosana/química , Concentração de Íons de Hidrogênio , Membranas Artificiais , Camundongos , Oscilometria , Plantas Medicinais , Polímeros/química , Polissacarídeos , Pós/química , Reologia , Espectroscopia de Infravermelho com Transformada de Fourier , Estresse Mecânico , Engenharia Tecidual/métodos , Viscosidade
15.
Mol Genet Genomic Med ; 9(3): e1559, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33465300

RESUMO

BACKGROUND: The impairment of the hepatic enzyme phenylalanine hydroxylase (PAH) causes elevation of phenylalanine levels in blood and other body fluids resulting in the most common inborn error of amino acid metabolism (phenylketonuria). Persistently high levels of phenylalanine lead to irreversible damage to the nervous system. Therefore, early diagnosis of the affected individuals is important, as it can prevent clinical manifestations of the disease. METHODS: In this report, the biochemical and genetic findings performed in 223 patients diagnosed through the Portuguese Neonatal Screening Program (PNSP) are presented. RESULTS: Overall, the results show that a high overlap exists between different types of variants and phenylalanine levels. Molecular analyses reveal a wide mutational spectrum in our population with a total of 56 previously reported variants, most of them found in compound heterozygosity (74% of the patients). Intragenic polymorphic markers were used to assess the haplotypic structure of mutated chromosomes for the most frequent variants found in homozygosity in our population (p.Ile65Thr, p.Arg158Gln, p.Leu249Phe, p.Arg261Gln, p.Val388Met, and c.1066-11G>A). CONCLUSION: Our data reveal high heterogeneity at the biochemical and molecular levels and are expected to provide a better understanding of the molecular basis of this disease and to provide clues to elucidate genotype-phenotype correlations.


Assuntos
Frequência do Gene , Fenótipo , Fenilalanina Hidroxilase/genética , Fenilcetonúrias/genética , Feminino , Haplótipos , Homozigoto , Humanos , Recém-Nascido , Masculino , Mutação , Triagem Neonatal , Fenilcetonúrias/epidemiologia , Portugal
17.
BMC Ecol ; 20(1): 52, 2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-32993600

RESUMO

BACKGROUND: The Schreiber's bat, Miniopterus schreibersii, is adapted to long-distance flight, yet long distance movements have only been recorded sporadically using capture-mark-recapture. In this study, we used the hydrogen isotopic composition of 208 wing and 335 fur specimens from across the species' European range to test the hypothesis that the species migrates over long distances. RESULTS: After obtaining the hydrogen isotopic composition (δ2H) of each sample, we performed geographic assignment tests by comparing the δ2H of samples with the δ2H of sampling sites. We found that 95 bats out of 325 showed evidence of long-distance movement, based on the analysis of either fur or wing samples. The eastern European part of the species range (Greece, Bulgaria and Serbia) had the highest numbers of bats that had moved. The assignment tests also helped identify possible migratory routes, such as movement between the Alps and the Balkans. CONCLUSIONS: This is the first continental-scale study to provide evidence of migratory behaviour of M. schreibersii throughout its European range. The work highlights the need for further investigation of this behaviour to provide appropriate conservation strategies.


Assuntos
Quirópteros , Animais , Europa (Continente) , Hidrogênio , Isótopos
18.
Carbohydr Polym ; 249: 116839, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32933683

RESUMO

The design of innovative pharmaceutical products, able to reach unexplored market niches, requires natural materials use with improved swelling and moisture properties. Herein, chitosan (CHT), a natural polymer, was combined with virgin coconut oil (VCO), a resource extracted from coconut kernels, to develop emulsion-based films for biomedical purposes. The film's properties were tuned by changing VCO concentrations, and the structural, morphological, and physical properties of the films were evaluated. The CHT/VCO-based film morphology showed the presence of VCO droplets at different sizes, both in the surface and inner part. Moreover, the capability to develop CHT/VCO-films as superabsorbent materials was shown. The film extracts cytotoxicity was assessed using human adipose stem cells, and metabolic activity was confirmed. The findings suggest that incorporating a small volume of VCO into the CHT system, superabsorbent materials with the potential to be applied in biomedical devices that require high swelling properties, can be developed.

19.
Mar Drugs ; 18(7)2020 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-32629815

RESUMO

Marine resources have considerable potential to develop high-value materials for applications in different fields, namely pharmaceutical, environmental, and biomedical. Despite that, the lack of solubility of marine-derived polymers in water and common organic solvents could restrict their applications. In the last years, ionic liquids (ILs) have emerged as platforms able to overcome those drawbacks, opening many routes to enlarge the use of marine-derived polymers as biomaterials, among other applications. From this perspective, ILs can be used as an efficient extraction media for polysaccharides from marine microalgae and wastes (e.g., crab shells, squid, and skeletons) or as solvents to process them in different shapes, such as films, hydrogels, nano/microparticles, and scaffolds. The resulting architectures can be applied in wound repair, bone regeneration, or gene and drug delivery systems. This review is focused on the recent research on the applications of ILs as processing platforms of biomaterials derived from marine polymers.


Assuntos
Organismos Aquáticos/química , Materiais Biocompatíveis , Líquidos Iônicos , Polímeros , Polissacarídeos
20.
J Invertebr Pathol ; 166: 107206, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31152770

RESUMO

Bat flies (Diptera: Nycteribiinae) are highly specialized bloodsucking bat ectoparasites. Some of the ectoparasitic bat flies are themselves parasitized with an ectoparasitic fungus of the genus Arthrorhynchus (Laboulbeniales). Ascospores of the fungus attach to the cuticle of a bat fly and develop a haustorium that penetrates the host cuticle. This interaction defines the fungus as a hyperparasite. Both the fly and the fungus are obligate parasites and this peculiar case of hyperparasitism has remained largely unstudied. We studied the prevalence of Laboulbeniales, genus Arthrorhynchus, in natural populations of bat flies infesting the bat species Miniopterus schreibersii, Myotis bechsteinii, My. blythii, My. daubentonii, My. escalerai and My. myotis in Portuguese caves. Laboulbeniales were found infecting 10 of the 428 screened bat flies (2.3%) in natural populations, with fewer infections in winter. Images obtained with transmission electron microscopy show the fungal haustorium within the bat fly host tissue, from where it extracts nutrition.


Assuntos
Quirópteros/parasitologia , Dípteros/parasitologia , Micoses/veterinária , Animais , Ascomicetos , Cavernas , Interações Hospedeiro-Parasita
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