Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 41
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
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
2.
Mar Drugs ; 21(2)2023 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-36827137

RESUMO

Arthropods, the largest animal phylum, including insects, spiders and crustaceans, are characterized by their bodies being covered primarily in chitin. Besides being a source of this biopolymer, crustaceans have also attracted attention from biotechnology given their cuticles' remarkable and diverse mechanical properties. The goose barnacle, Pollicipes pollicipes, is a sessile crustacean characterized by their body parts covered with calcified plates and a peduncle attached to a substrate covered with a cuticle. In this work, the composition and structure of these plates and cuticle were characterized. The morphology of the tergum plate revealed a compact homogeneous structure of calcium carbonate, a typical composition among marine invertebrate hard structures. The cuticle consisted of an outer zone covered with scales and an inner homogenous zone, predominantly organic, composed of successive layers parallel to the surface. The scales are similar to the tergum plate and are arranged in parallel and oriented semi-vertically. Structural and biochemical characterization confirmed a bulk composition of ɑ-chitin and suggested the presence of elastin-based proteins and collagen. The mechanical properties of the cuticle showed that the stiffness values are within the range of values described in elastomers and soft crustacean cuticles resulting from molting. The removal of calcified components exposed round holes, detailed the structure of the lamina, and changed the protein properties, increasing the rigidity of the material. This flexible cuticle, predominantly inorganic, can provide bioinspiration for developing biocompatible and mechanically suitable biomaterials for diverse applications, including in tissue engineering approaches.


Assuntos
Artrópodes , Thoracica , Animais , Thoracica/metabolismo , Quitina/química
3.
Molecules ; 28(3)2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36770658

RESUMO

The demand for bio-based and safer composite materials is increasing due to the growth of the industry, human population, and environmental concerns. In this framework, sustainable and safer cork-polymer composites (CPC), based on green low-density polyethylene (LDPE) were developed using melt-based technologies. Chitosan and polyethylene-graft-maleic anhydride (PE-g-MA) were employed to enhance the CPC's properties. The morphology, wettability, mechanical, thermal, and antibacterial properties of the CPC against Pseudomonas putida (P. putida) and Staphylococcus aureus (S. aureus) were examined. The CPC showed improved stiffness when compared with that of the LDPE matrix, preferably when combined with chitosan and PE-g-MA (5 wt. %), reinforcing the stiffness (58.8%) and the strength (66.7%). Chitosan also increased the composite stiffness and strength, as well as reduced the surface hydrophilicity. The CPCs' antibacterial activity revealed that cork significantly reduces the biofilm on the polymer matrix. The highest biofilm reduction was found with CPC containing cork and 5 wt. % chitosan for both P. putida (54% reduction) and S. aureus (36% reduction), confirming their potential to extend the lifespan of products for packaging and healthcare, among other applications. This work leads to the understanding of the factors that influence biofilm formation in cork composites and provides a strategy to reinforce their behavior using chitosan.


Assuntos
Incrustação Biológica , Quitosana , Humanos , Quitosana/farmacologia , Polietileno , Incrustação Biológica/prevenção & controle , Staphylococcus aureus , Antibacterianos/farmacologia , Polímeros
4.
Infection ; 49(3): 377-385, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33393066

RESUMO

PURPOSE: CRISPR gene-editing technology has the potential to transform the diagnosis and treatment of infectious diseases, but most clinicians are unaware of its broad applicability. Derived from an ancient microbial defence system, these so-called "molecular scissors" enable precise gene editing with a low error rate. However, CRISPR systems can also be targeted against pathogenic DNA or RNA sequences. This potential is being combined with innovative delivery systems to develop new therapeutic approaches to infectious diseases. METHODS: We searched Pubmed and Google Scholar for CRISPR-based strategies in the diagnosis and treatment of infectious diseases. Reference lists were reviewed and synthesized for narrative review. RESULTS: CRISPR-based strategies represent a novel approach to many challenging infectious diseases. CRISPR technologies can be harnessed to create rapid, low-cost diagnostic systems, as well as to identify drug-resistance genes. Therapeutic strategies, such as CRISPR systems that cleave integrated viral genomes or that target resistant bacteria, are in development. CRISPR-based therapies for emerging viruses, such as SARS-CoV-2, have also been proposed. Finally, CRISPR systems can be used to reprogram human B cells to produce neutralizing antibodies. The risks of CRISPR-based therapies include off-target and on-target modifications. Strategies to control these risks are being developed and a phase 1 clinical trials of CRISPR-based therapies for cancer and monogenic diseases are already underway. CONCLUSIONS: CRISPR systems have broad applicability in the field of infectious diseases and may offer solutions to many of the most challenging human infections.


Assuntos
Sistemas CRISPR-Cas , Doenças Transmissíveis/diagnóstico , Doenças Transmissíveis/terapia , Animais , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/patogenicidade , Edição de Genes , Humanos , Técnicas de Diagnóstico Molecular , Terapia de Alvo Molecular , Vírus/genética , Vírus/isolamento & purificação , Vírus/patogenicidade
5.
Molecules ; 26(6)2021 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-33804712

RESUMO

Pathogenic microbes are a major source of health and environmental problems, mostly due to their easy proliferation on most surfaces. Currently, new classes of antimicrobial agents are under development to prevent microbial adhesion and biofilm formation. However, they are mostly from synthetic origin and present several disadvantages. The use of natural biopolymers such as cellulose, hemicellulose, and lignin, derived from lignocellulosic materials as antimicrobial agents has a promising potential. Lignocellulosic materials are one of the most abundant natural materials from renewable sources, and they present attractive characteristics, such as low density and biodegradability, are low-cost, high availability, and environmentally friendly. This review aims to provide new insights into the current usage and potential of lignocellulosic materials (biopolymer and fibers) as antimicrobial materials, highlighting their future application as a novel drug-free antimicrobial polymer.


Assuntos
Anti-Infecciosos/química , Lignina/química
6.
Mar Drugs ; 16(8)2018 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-30081528

RESUMO

The high prevalence of bone defects has become a worldwide problem. Despite the significant amount of research on the subject, the available therapeutic solutions lack efficiency. Autografts, the most commonly used approaches to treat bone defects, have limitations such as donor site morbidity, pain and lack of donor site. Marine resources emerge as an attractive alternative to extract bioactive compounds for further use in bone tissue-engineering approaches. On one hand they can be isolated from by-products, at low cost, creating value from products that are considered waste for the fish transformation industry. One the other hand, religious constraints will be avoided. We isolated two marine origin materials, collagen from shark skin (Prionace glauca) and calcium phosphates from the teeth of two different shark species (Prionace glauca and Isurus oxyrinchus), and further proposed to mix them to produce 3D composite structures for hard tissue applications. Two crosslinking agents, 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride/N-Hydroxysuccinimide (EDC/NHS) and hexamethylene diisocyanate (HMDI), were tested to enhance the scaffolds' properties, with EDC/NHS resulting in better properties. The characterization of the structures showed that the developed composites could support attachment and proliferation of osteoblast-like cells. A promising scaffold for the engineering of bone tissue is thus proposed, based on a strategy of marine by-products valorisation.


Assuntos
Apatitas/química , Colágeno/química , Tubarões , Alicerces Teciduais/química , Animais , Apatitas/isolamento & purificação , Materiais Biocompatíveis/química , Materiais Biocompatíveis/isolamento & purificação , Osso e Ossos/lesões , Colágeno/isolamento & purificação , Reagentes de Ligações Cruzadas/química , Regeneração Tecidual Guiada/métodos , Teste de Materiais , Engenharia Tecidual/métodos
7.
Rapid Commun Mass Spectrom ; 28(21): 2275-84, 2014 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-25279740

RESUMO

RATIONALE: Glycosphingolipids are important lipid molecules namely as constituents of the plasma membrane organized in lipid rafts, in signal transduction, and cell-cell communication. Although many human diseases are associated with oxidative stress and lipid oxidation, a link between oxidative stress and modification of glycosphingolipids has never been addressed. METHODS: In this study, the structural changes caused by UVA-induced photooxidation of galactosyl- (GalCer) and lactosylceramide (LacCer) molecular species were studied by electrospray ionization mass spectrometry (ESI-MS and MS/MS), using a quadrupole time-of-flight (QTOF) mass spectrometer and high-performance liquid chromatography/tandem mass spectrometry with a C5 stationary phase (C5 HPLC/MS/MS) using a linear ion trap. RESULTS: ESI-MS spectra of GalCer and LacCer after photooxidation showed new ions with a mass shift of +32 Da when compared with the ions of the non-modified glycosphingolipids. These new species were assigned as hydroperoxyl derivatives, confirmed by HPLC/MS/MS and through FOX 2 assay. In the ESI-MS and LC/MS of lactosylceramide a new ion with lower m/z value, assigned as glucosylceramide (GlcCer) + 32 Da, was also detected and proposed to be formed due to oxidative cleavage of lactosyl moieties. ESI-MS/MS of the oxidized species allowed us to infer the presence of isomeric hydroperoxyl derivatives, with the hydroperoxyl moiety either linked to the sphingosine backbone or in the unsaturated acyl chain. Oxidation in the sugar moieties was observed in the case of LacCer, suggesting an oxidation via radical reactive oxygen species that can induce the oxidative cleavage of the lactosyl moiety. CONCLUSIONS: This study shows that glycosphingolipids are prone to oxidation and the identified mass spectrometry fingerprint of oxidized galactosyl- and lactosylceramide species will support their future identification in lipidomic studies of biological samples under oxidative conditions.


Assuntos
Antígenos CD/química , Galactosilceramidas/química , Lactosilceramidas/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Antígenos CD/efeitos da radiação , Cromatografia Líquida de Alta Pressão/métodos , Galactosilceramidas/efeitos da radiação , Lactosilceramidas/efeitos da radiação , Oxirredução , Processos Fotoquímicos , Espectrometria de Massas em Tandem , Raios Ultravioleta
8.
Polymers (Basel) ; 16(9)2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38732755

RESUMO

The last few decades have witnessed significant advances in the development of polymeric-based foam materials. These materials find several practical applications in our daily lives due to their characteristic properties such as low density, thermal insulation, and porosity, which are important in packaging, in building construction, and in biomedical applications, respectively. The first foams with practical applications used polymeric materials of petrochemical origin. However, due to growing environmental concerns, considerable efforts have been made to replace some of these materials with biodegradable polymers. Foam processing has evolved greatly in recent years due to improvements in existing techniques, such as the use of supercritical fluids in extrusion foaming and foam injection moulding, as well as the advent or adaptation of existing techniques to produce foams, as in the case of the combination between additive manufacturing and foam technology. The use of supercritical CO2 is especially advantageous in the production of porous structures for biomedical applications, as CO2 is chemically inert and non-toxic; in addition, it allows for an easy tailoring of the pore structure through processing conditions. Biodegradable polymeric materials, despite their enormous advantages over petroleum-based materials, present some difficulties regarding their potential use in foaming, such as poor melt strength, slow crystallization rate, poor processability, low service temperature, low toughness, and high brittleness, which limits their field of application. Several strategies were developed to improve the melt strength, including the change in monomer composition and the use of chemical modifiers and chain extenders to extend the chain length or create a branched molecular structure, to increase the molecular weight and the viscosity of the polymer. The use of additives or fillers is also commonly used, as fillers can improve crystallization kinetics by acting as crystal-nucleating agents. Alternatively, biodegradable polymers can be blended with other biodegradable polymers to combine certain properties and to counteract certain limitations. This work therefore aims to provide the latest advances regarding the foaming of biodegradable polymers. It covers the main foaming techniques and their advances and reviews the uses of biodegradable polymers in foaming, focusing on the chemical changes of polymers that improve their foaming ability. Finally, the challenges as well as the main opportunities presented reinforce the market potential of the biodegradable polymer foam materials.

9.
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
10.
Cureus ; 15(12): e50770, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38239517

RESUMO

We present the case of a 74-year-old woman, functionally independent in her daily activities, with a medical history notable for hypertension and dyslipidemia. She presented to the emergency room with an altered level of consciousness, opening her eyes only to pain, no verbal response, and flexion withdrawal from pain coupled with a Glasgow Coma Scale of 7. The intensive care unit was promptly summoned, and the patient was intubated and admitted to intensive care. Comprehensive laboratory assessments revealed no abnormalities and an initial cerebral CT scan showed no acute changes. A subsequent CT scan performed 24 hours post-event disclosed bilateral ischemia affecting the territories of the anterior and middle cerebral arteries. Regrettably, this catastrophic event precluded any potential for recovery. Consequently, the decision was made not to pursue further investigations to determine the underlying cause. The medical team opted for supportive treatment and comfort measures. Tragically, the patient died on the 37th day of hospital admission.

11.
Biomater Adv ; 147: 213320, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36739783

RESUMO

The thymus coordinates the development and selection of T cells. It is structured into two main compartments: the cortex and the medulla. The replication of such complex 3D environment has been challenged by bioengineering approaches. Nevertheless, the effect of the scaffold microstructure on thymic epithelial cell (TEC) cultures has not been deeply investigated. Here, we developed bilayered porous silk fibroin scaffolds and tested their effect on TEC co-cultures. The small and large pore scaffolds presented a mean pore size of 84.33 ± 21.51 µm and 194.90 ± 61.38 µm, respectively. The highly porous bilayered scaffolds presented a high water absorption and water content (> 94 %), together with mechanical properties in the range of the native tissue. TEC (i.e., medullary (mTEC) and cortical (cTEC) cell lines) proliferation is increased in scaffolds with larger pores. The co-culture of both TEC lines in the bilayered porous silk scaffolds presents enhanced cell proliferation and metabolic activity when compared with mTEC in single culture. Also, when the co-culture occurred with cTEC in the small pores layer and mTEC in the large pores layer, a 9.2- and 18.9-fold increase in Foxn1 and Icam1 gene expression in cTEC is evident. These results suggest that scaffold microstructure and the co-culture influence TEC's behaviour. Bilayered silk scaffolds with adjusted microstructure are a valid alternative for TEC culture, having possible applications in advanced thymus bioengineering strategies.


Assuntos
Seda , Timo , Seda/metabolismo , Porosidade , Timo/metabolismo , Engenharia Tecidual/métodos , Bioengenharia
12.
J Biomed Mater Res B Appl Biomater ; 111(2): 261-270, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36507698

RESUMO

The treatment of bone regeneration failures has been constantly improved with the study of new biomaterials. Techgraft® is a collagen membrane derived from bovine pericardium, which has been shown to have biocompatibility and effectiveness in tissue repair. However, its use in orthopedics has not yet been evaluated. Therefore, the purpose of this study was to characterize a bovine pericardium collagen membrane and evaluate the effects of its use in the regeneration of a bone defect in rat tibia. Scanning electron microscopy, atomic force microscopy, weight lost and water uptake tests, and mechanical test were performed. Afterwards, the membrane was tested in an experimental study, using 12 male Sprague Dawley rats. A bone defect was surgically made in tibiae of animals, which were assigned to two groups (n = 6): bone defect treated with collagen membrane (TG) and bone defect without treatment (CONT). Then, tibiae were submitted to micro-CT. The membranes preserved their natural collagen characteristics, presenting great strength, high water absorption, hydrophilicity, and almost complete dissolution in 30 days. In the experimental study, the membrane enhanced the growth of bone tissue in contact with its surface. A higher bone volume and trabeculae number and less trabecular space was observed in bone defects of the membrane group compared to the control group at 21 days. In conclusion, the Techgraft membrane seems to have favorable characteristics for treatment of long bone repair.


Assuntos
Regeneração Óssea , Colágeno , Bovinos , Masculino , Animais , Ratos , Ratos Sprague-Dawley , Colágeno/farmacologia , Materiais Biocompatíveis , Pericárdio , Tíbia , Água , Membranas Artificiais
13.
Bioengineering (Basel) ; 10(1)2023 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-36671634

RESUMO

Corneal pathologies from infectious or noninfectious origin have a significant impact on the daily lives of millions of people worldwide. Despite the risk of organ rejection or infection, corneal transplantation is currently the only effective treatment. Finding safe and innovative strategies is the main goal of tissue-engineering-based approaches. In this study, the potential of gelatin methacryloyl (GelMA) hydrogels produced from marine-derived gelatin and loaded with ascorbic acid (as an enhancer of the biological activity of cells) was evaluated for corneal stromal applications. Marine GelMA was synthesized with a methacrylation degree of 75%, enabling effective photocrosslinking, and hydrogels with or without ascorbic acid were produced, encompassing human keratocytes. All the produced formulations exhibited excellent optical and swelling properties with easy handling as well as structural stability and adequate degradation rates that may allow proper extracellular matrix remodeling by corneal stromal cells. Formulations loaded with 0.5 mg/mL of ascorbic acid enhanced the biological performance of keratocytes and induced collagen production. These results suggest that, in addition to marine-derived gelatin being suitable for the synthesis of GelMA, the hydrogels produced are promising biomaterials for corneal regeneration applications.

14.
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.

15.
Front Neural Circuits ; 17: 1293620, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38186631

RESUMO

In vivo recordings in freely behaving animals are crucial to understand the neuronal circuit basis of behavior. Although current multi-channel silicon probes provide unparalleled sampling density, the study of interacting neuronal populations requires the implantation of multiple probes across different regions of the brain. Ideally, these probes should be independently adjustable, to maximize the yield, and recoverable, to mitigate costs. In this work, we describe the implementation of a miniaturized 3D-printed headgear system for chronic in vivo recordings in mice using independently movable silicon probes targeting multiple brain regions. We successfully demonstrated the performance of the headgear by simultaneously recording the neuronal activity in the prelimbic cortex and dorsal hippocampus. The system proved to be sturdy, ensuring high-quality stable recordings and permitted reuse of the silicon probes, with no observable interference in mouse innate behaviors.


Assuntos
Encéfalo , Silício , Animais , Camundongos , Córtex Cerebral , Hipocampo
16.
Front Cell Neurosci ; 16: 874310, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35634473

RESUMO

Social status is recognized as a major determinant of social behavior and health among animals; however, the neural circuits supporting the formation and navigation of social hierarchies remain under extensive research. Available evidence suggests the prefrontal cortex is a keystone in this circuit, but upstream and downstream candidates are progressively emerging. In this review, we compare and integrate findings from rodent and primate studies to create a model of the neural and cellular networks supporting social hierarchies, both from a macro (i.e., circuits) to a micro-scale perspective (microcircuits and synapses). We start by summarizing the literature on the prefrontal cortex and other relevant brain regions to expand the current "prefrontal-centric" view of social hierarchy behaviors. Based on connectivity data we also discuss candidate regions that might inspire further investigation, as well as the caveats and strategies that have been used to further our understanding of the biological substrates underpinning social hierarchy and dominance.

17.
Biomaterials ; 290: 121829, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36194954

RESUMO

Recombinant spider silk materials with antimicrobial peptides are a promising new class of drug-free antimicrobial materials capable of preventing surgical site infections (SSI), but their potential to impede infections is unclear. Herein, we aimed to unravel the biological and inflammatory potential of bioengineered spider silk materials to prevent SSI using an infection animal model. Silk-like fibers made of silk fibroin and spider silk proteins with antimicrobial peptides (6mer-HNP1) held improved stiffness (2.9 GPa) and had a slow biodegradation profile while inhibiting bacterial adherence in vitro by 5-log and 6-log reduction on Methicillin-Resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli), respectively. In vivo studies showed that fibers with 6mer-HNP1 elicited a short-term low to mild local inflammatory response, similar to implanted commercial sutures. In the presence of a bacterial infection, the mediators related to infection and inflammation were downregulated suggesting that the fibers maintained a low but active response to bacterial infection. Thus, the presence of 6mer-HNP1 helped the host maintain an active response to bacterial infection, impairing the development of an acute infection. Our findings further support the use of bioengineered spider silk proteins to develop drug-free antimicrobial sutures capable to impair SSI.


Assuntos
Anti-Infecciosos , Infecções Bacterianas , Staphylococcus aureus Resistente à Meticilina , Aranhas , Animais , Escherichia coli , Suturas , Seda/química , Infecção da Ferida Cirúrgica/prevenção & controle , Antibacterianos/farmacologia
18.
Porto Biomed J ; 7(3): e147, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35801219

RESUMO

Although more commonly seen in adult population, posterior reversible encephalopathy syndrome (PRES) can also be observed in pediatric patients. The etiopathogenesis of pediatric PRES is poorly understood, and the available evidence comes mostly from childhood cancer. Analysis of the sociodemographic and clinical characteristics of the different noncancer-related types can improve the understanding of pediatric PRES. Methods: Systematic review of characteristics and outcome of noncancer pediatric PRES. Primary sources of investigation were identified and selected through Pubmed and Scopus databases. The research was complemented by reference search in relevant publications. Study protocol was registered (Prospero CRD42020165798). Results: We identified 449 cases of noncancer pediatric PRES from 272 studies, median age 10 (newborn to 17 years), 49.9% girls. The 4 most common groups of conditions were renal 165 (36.7%), hematologic 84 (18.7%), autoimmune 64 (14.3%), and cardiovascular 28 (6.2%) disorders. The 4 most prevalent precipitants identified were hypertensive crisis 119 (26.5%), corticosteroids 56 (12.5%), immunosuppression drugs 44 (9.8%), and biologic drugs 14 (3.1%). Clinical presentations included seizures 100 (22.3%), headaches 22 (4.9%), encephalopathy 17 (3.8%), visual disturbances 6 (1.3%), and focal deficit 3 (0.7%). The distribution of lesions was (n = 380): combined anterior/posterior circulation (40.8%), isolated posterior circulation (24.1%), anterior circulation (6.2%), and deep structures (1.6%). Residual neurological deficits occurred in about 1 out 10 cases. Conclusion: Pediatric PRES differs from the adult in etiology, precipitants, and clinical manifestations. Renal diseases predominate, acute raised blood pressure is less frequent, and cortical deficits are rarer. In addition, the proportion of patients with combined anterior/posterior circulation was higher. Permanent neurological sequels can occur.

19.
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.

20.
Acta Biomater ; 147: 168-184, 2022 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-35580828

RESUMO

The combination of natural resources with biologically active biocompatible ionic liquids (Bio-IL) is presented as a combinatorial approach for developing tools to manage inflammatory diseases. Innovative biomedical solutions were constructed combining silk fibroin (SF) and Ch[Gallate], a Bio-IL with antioxidant and anti-inflammatory features, as freeze-dried 3D-based sponges. An evaluation of the effect of the Ch[Gallate] concentration (≤3% w/v) on the SF/Ch[Gallate] sponges was studied. Structural changes observed on the sponges revealed that the Ch[Gallate] presence positively affected the ß-sheet formation while not influencing the silk native structure, which was suggested by the FTIR and solid-state NMR results, respectively. Also, it was possible to modulate their mechanical properties, antioxidant activity and stability/degradation in an aqueous environment, by changing the Ch[Gallate] concentration. The architectures showed high water uptake ability and a weight loss that follows the controlled Ch[Gallate] release rate studied for 7 days. Furthermore, the sponges supported human adipose stem cells growth and proliferation, up to 7 days. TNF-α, IL-6 (pro-inflammatory) and IL-10 (anti-inflammatory) release quantification from a human monocyte cell line revealed a decrease in the pro-inflammatory cytokines concentrations in samples containing Ch[Gallate]. These outcomes encourage the use of the developed architectures as tissue engineering solutions, potentially targeting inflammation processes. STATEMENT OF SIGNIFICANCE: Combining natural resources with active biocompatible ionic liquids (Bio-IL) is herein presented as a combinatorial approach for the development of tools to manage inflammatory diseases. We propose using silk fibroin (SF), a natural protein, with cholinium gallate, a Bio-IL, with antioxidant and anti-inflammatory properties, to construct 3D-porous sponges through a sustainable methodology. The morphological features, swelling, and stability of the architectures were controlled by Bio-IL content in the matrices. The sponges were able to support human adipose stem cells growth and proliferation, and their therapeutic effect was proved by the blockage of TNF-α from activated and differentiated THP-1 monocytes. We believe that these bio-friendly and bioactive SF/Bio-IL-based sponges are effective for targeting pathologies with associated inflammatory processes.


Assuntos
Fibroínas , Líquidos Iônicos , Antioxidantes/farmacologia , Materiais Biocompatíveis/química , Fibroínas/química , Fibroínas/farmacologia , Ácido Gálico , Humanos , Seda/química , Engenharia Tecidual , Alicerces Teciduais/química , Fator de Necrose Tumoral alfa
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA