RESUMO
Polysaccharides from pomegranate peel (Wonderful and Purple Queen® varieties) were extracted by hot water and fractionated using ethanol. Three fractions (F1-F2-F3) were obtained for each sample. Polysaccharides' yield was higher for Purple Queen®: 13% dw. Polysaccharides of the three fractions were characterized by size exclusion chromatography (SEC), dynamic light scattering (DLS), 1H NMR, methylation, and acylation degree. Differently from SEC, DLS highlighted some differences between the polysaccharides's molecular sizes of the fractions. The highest methylation and acylation degree was observed for F3 of Purple Queen®: 74.0% and 18.6%, respectively. The percentage of galacturonic acid confirmed the presence of pectin in almost all the fractions recognized as homogalacturonan. Arabinan and arabinogalactan were also found in all the collected F3 samples, although in different proportions. The stepwise fractionation process followed by a multi-methodological analytical investigation was helpful to improve the knowledge of the pectic polysaccharides of pomegranate.
Assuntos
Punica granatum , Fracionamento Químico , Frutas/química , Pectinas/química , Polissacarídeos/químicaRESUMO
Resumo Além de ser uma modalidade de enfrentamento, ressignificação do sofrimento e concepção de vida, a espiritualidade é fonte de esperança e confiança para pacientes oncológicos. Com base nessas premissas, objetivou-se desvelar a concepção de espiritualidade de pacientes oncológicos em tratamento antineoplásico a fim de compreender sua influência no enfrentamento da doença. Trata-se de estudo descritivo, de delineamento qualitativo, realizado no ambulatório de quimioterapia de um hospital público brasileiro. A amostra foi composta por 18 pacientes oncológicos submetidos a sessões de quimioterapia, em tratamento ambulatorial, maiores de 18 anos, de ambos os sexos. Para confecção dos resultados, utilizou-se a análise de conteúdo temática, que revelou duas categorias: 1) espiritualidade como fonte de esperança e confiança; e 2) espiritualidade como fonte de ressignificação do sofrimento e de uma renovada concepção de vida.
Abstract In addition to being a way of coping with and attributing new meanings to suffering and conceiving life, spirituality is a source of hope and confidence for cancer patients. From these premises, the aim of this study was to present the perception of spirituality of cancer patients undergoing antineoplastic treatment in order to understand its influence on how patients cope with the disease. This is a descriptive and qualitative study carried out in the outpatient chemotherapy clinic of a Brazilian public hospital. The study sample consisted of 18 cancer patients undergoing outpatient chemotherapy, over 18 years of age, of both genders. Thematic content analysis was used, which revealed two thematic categories: 1) spirituality as a source of hope and confidence; and 2) spirituality as a source of new meanings to suffering and of a renewed view of life.
Resumen Además de ser una modalidad de afrontamiento, resignificación del sufrimiento y concepción de la vida, la espiritualidad es una fuente de esperanza y confianza para los pacientes oncológicos. Partiendo de estas premisas, el objetivo de este trabajo fue desvelar la concepción de la espiritualidad de los pacientes con cáncer sometidos a tratamiento antineoplásico para comprender su influencia en el afrontamiento de la enfermedad. Se trata de un estudio descriptivo de diseño cualitativo, realizado en el ambulatorio de quimioterapia de un hospital público brasileño. La muestra se compuso de 18 pacientes oncológicos sometidos a sesiones de quimioterapia, en tratamiento ambulatorio, mayores de 18 años, de ambos sexos. Para confeccionar los resultados, se utilizó el análisis de contenido temático, que reveló dos categorías: 1) la espiritualidad como fuente de esperanza y confianza; y 2) la espiritualidad como fuente de resignificación del sufrimiento y de una concepción renovada de la vida.
Assuntos
Pacientes , Religião , Espiritualidade , Pesquisa Qualitativa , Oncologia , Neoplasias , AntineoplásicosRESUMO
Bacterial biofilms are a major health concern, mainly due to their contribution to increased bacterial resistance to well-known antibiotics. The conventional treatment of biofilms represents a challenge, and frequently, eradication is not achieved with long-lasting administration of antibiotics. In this context, the present work proposes an innovative therapeutic approach that is focused on the encapsulation of N-acetyl-l-cysteine (NAC) into lipid nanoparticles (LNPs) functionalized with d-amino acids to target and disrupt bacterial biofilms. The optimized formulations presented a mean hydrodynamic diameter around 200 nm, a low polydispersity index, and a high loading capacity. These formulations were stable under storage conditions up to 6 months. In vitro biocompatibility studies showed a low cytotoxicity effect in fibroblasts and a low hemolytic activity in human red blood cells. Nevertheless, unloaded LNPs showed a higher hemolytic potential than NAC-loaded LNPs, which suggests a safer profile of the latter. The in vitro antibiofilm efficacy of the developed formulations was tested against Staphylococcus epidermidis (Gram-positive) and Pseudomonas aeruginosa (Gram-negative) mature biofilms. The results showed that the NAC-loaded LNPs were ineffective against S. epidermidis biofilms, while a significant reduction of biofilm biomass and bacterial viability in P. aeruginosa biofilms were observed. In a more complex therapeutic approach, the LNPs were further combined with moxifloxacin, revealing a beneficial effect between the LNPs and the antibiotic against P. aeruginosa biofilms. Both alone and in combination with moxifloxacin, unloaded and NAC-loaded LNPs functionalized with d-amino acids showed a great potential to reduce bacterial viability, with no significant differences in the presence or absence of NAC. However, the presence of NAC in NAC-loaded functionalized LNPs shows a safer profile than the unloaded LNPs, which is beneficial for an in vivo application. Overall, the developed formulations present a potential therapeutic approach against P. aeruginosa biofilms, alone or in combination with antibiotics.
Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Portadores de Fármacos/farmacologia , Lipossomos/química , Nanopartículas/química , Pseudomonas aeruginosa/efeitos dos fármacos , Acetilcisteína/química , Acetilcisteína/toxicidade , Animais , Antibacterianos/química , Antibacterianos/toxicidade , Linhagem Celular , Portadores de Fármacos/química , Portadores de Fármacos/toxicidade , Sinergismo Farmacológico , Humanos , Lipossomos/toxicidade , Camundongos , Testes de Sensibilidade Microbiana , Moxifloxacina/farmacologia , Nanopartículas/toxicidade , Palmitatos/química , Palmitatos/toxicidade , Fosfatidiletanolaminas/química , Fosfatidiletanolaminas/toxicidade , Polietilenoglicóis/química , Polietilenoglicóis/toxicidade , Pseudomonas aeruginosa/fisiologiaRESUMO
A levan-type fructooligosaccharide was produced by a Paenibacillus strain isolated from Brazilian crude oil, the purity of which was 98.5% after precipitation with ethanol and dialysis. Characterization by FTIR, NMR spectroscopy, GC-FID and ESI-MS revealed that it is a mixture of linear ß(2 â 6) fructosyl polymers with average degree of polymerization (DP) of 18 and branching ratio of 20. Morphological structure and physicochemical properties were investigated to assess levan microstructure, degradation temperature and thermomechanical features. Thermal Gravimetric Analysis highlighted degradation temperature of 218 °C, Differential Scanning Calorimetry (DSC) glass transition at 81.47 °C, and Dynamic Mechanical Analysis three frequency-dependent transition peaks. These peaks, corresponding to a first thermomechanical transition event at 86.60 °C related to the DSC endothermic event, a second at 170.9 °C and a third at 185.2 °C, were attributed to different glass transition temperatures of oligo and polyfructans with different DP. Levan showed high morphological versatility and technological potential for the food, nutraceutical, and pharmaceutical industries.
Assuntos
Frutanos/isolamento & purificação , Paenibacillus/metabolismo , Petróleo/microbiologia , Configuração de Carboidratos , Fracionamento Químico , Temperatura Alta , Relação Estrutura-Atividade , VitrificaçãoRESUMO
The natural world holds useful resources that can be exploited to design effective therapeutic approaches. Ready-to-use tubular nanoclays, such as halloysite clay nanotubes (HNTs), are widely available, cost-effective, and sustainable submicron crystalline materials that have been showing great potential towards chronic multifactorial and malignant diseases, standing out as a promising anticancer nanotherapeutic strategy. Currently, several preclinical studies have reported the application of HNTs in cancer research, diagnosis, monitoring, and therapeutics. This groundbreaking review highlights the preclinical knowledge hitherto collected concerning the application of HNTs towards cancer therapy. Despite their reproducibility issues, HNTs were used as nanoarchitectonic platforms for the delivery of conventional chemotherapeutic, natural-occurring, biopharmaceutical, and phototherapeutic anticancer agents in a wide range of in vitro and in vivo solid cancer models. Overall, in different types of cancer mice models, the intratumoral and intravenous administration of HNTs-based nanoplatforms induced tumor growth inhibition without causing significant toxic effects. Such evidence raises a relevant question: does the therapeutic benefit of the parenteral administration of HNTs in cancer outweigh their potential toxicological risk? To answer this question further long-term absorption-distribution-metabolism-excretion studies in healthy and cancer animal models need to be performed. In cancer therapeutics, HNTs are envisaged as promising platforms for cancer multi-agent therapy, enabling the combination of different therapeutic modalities. Furthermore, HNTs might constitute suitable nanotheranostic platforms. Nevertheless, to confirm the potential and safety of the application of HNTs as nanodelivery systems for cancer therapy, it is necessary to perform in-depth in vivo pharmacokinetics and pharmacodynamic studies to further the translation to clinical trials.
Assuntos
Nanotubos , Neoplasias , Animais , Argila , Camundongos , Neoplasias/tratamento farmacológico , Reprodutibilidade dos TestesRESUMO
The small amount of proteins in starch-rich food industry byproducts can be an advantage to crosslink with genipin and tailor the performance of biobased films. In this work, genipin was combined with non- purified starch recovered from industrial potato washing slurries and used for films production. Starch recovered from potato washing slurries contained 0.75% protein, 2 times higher than starch directly obtained from potato and 6 times higher than the commercial one. Starch protein-genipin networks were formed with 0.05% and 0.10% genipin, gelatinized at 75 °C and 95 °C in presence of 30% glycerol. Bluish colored films were obtained in all conditions, with the higher surface roughness (Ra, 1.22 µm), stretchability (elongation, 31%), and hydrophobicity (water contact angle, 127°) for 0.10% genipin and starch gelatinized at 75 °C. Therefore, starch-rich byproducts, when combined with genipin, are promising for surpassing the starch-based films hydrophilicity and mechanical fragilities while providing light barrier properties.
Assuntos
Iridoides/química , Amido/química , Biocombustíveis , Reagentes de Ligações Cruzadas , Indústria Alimentícia , Fenômenos Mecânicos , Microscopia de Força Atômica , Proteínas de Plantas/análise , Reologia , Solanum tuberosum/química , Solubilidade , Propriedades de Superfície , SuspensõesRESUMO
Food processing wastes together with the perishable foodstuff loss promote environmental and societal concerns. Food byproducts can have value as a source of functional molecules for developing active packaging without food waste, under a circular economy. Nevertheless, the often-associated extraction/chemical processes compromise the sustainability of food byproducts reusability. In this work, coffee silverskin (CS) and starch, recovered from coffee roasting and potato industries, respectively, were together gelatinized to form in-situ films. Targeting to fit with the food application requirements, it is important to understand the influence of crude CS amount (1%, 5%, and 10% w/w of dry starch weight) on potato starch-based film properties. CS conferred a brownish coloration to the films, maintaining their transparency. The films colour intensity, antioxidant activity, and water tolerance were directly related with the CS dosage. Moreover, as high the CS amount, higher the elasticity, stretchability, and UV radiation absorption of the pristine films. These data emphasized that CS molecules extracted during gelatinization prevented the starch-starch hydrogen bonding and conferred functional and barrier properties. Overall, adding crude CS during potato starch gelatinization revealed to be an efficient strategy to tune the performance of potato starch-based films, opening an opportunity for valorising coffee roasting and potato byproducts.
Assuntos
Eliminação de Resíduos , Solanum tuberosum , Antioxidantes , Café , Alimentos , AmidoRESUMO
Agrofood byproducts may be exploited as a source of biomolecules suitable for developing bioplastic materials. In this work, the feasibility of using starch, oil, and waxes recovered from potato chips byproducts for films production was studied. The recovered potato starch-rich fraction (RPS) contained an amylopectin/amylose ratio of 2.3, gelatinization temperatures varying from 59 to 71⯰C, and a gelatinization enthalpy of 12.5â¯J/g, similarly to a commercial potato starch (CPS). Despite of its spherical and oval granules identical to CPS, RPS had a more amorphous structure and gave rise to low viscous suspensions, contradicting the typical B-type polymorph crystal structure and sluggish dispersions of CPS, respectively. When used for films production, RPS originated transparent films with lower roughness and wettability than CPS-based films, but with higher stretchability. In turn, when combined with RPS and CPS, oil or waxes recovered from frying residues and potato peels, respectively, allowed to develop transparent yellowish RPS- and CPS-based films with increased surface hydrophobicity, mechanical traction resistance, elasticity, and/or plasticity. Therefore, potato chips industry byproducts revealed to have thermoplastic and hydrophobic biomolecules that can be used to efficiently develop biobased plastics with improved surface properties and flexibility, opening an opportunity for their valorization.
Assuntos
Filmes Comestíveis , Óleos de Plantas/química , Solanum tuberosum/química , Amido/química , Ceras/química , Amilopectina/química , Amilose/química , Fenômenos Químicos , Interações Hidrofóbicas e Hidrofílicas , Microscopia de Força Atômica , Tamanho da Partícula , SolubilidadeRESUMO
The main objective of this study was to clarify the topical mechanisms underlying diclofenac-induced gastric toxicity by considering for the first time both ionization states of this nonsteroidal anti-inflammatory drug. 1,2-Dimyristoyl-sn-glycero-3-phosphocholine (DMPC) liposomes were the model system chosen to mimic the protective phospholipid layers of the gastric mucosa and to describe the interactions with diclofenac, considering the pH gradient found in the gastric mucosa (3 < pH < 7.4). Complementary experimental techniques were combined to evaluate the drug's affinity for DMPC bilayers, as well as to assess the drug's effects on the structural properties of the phospholipid bilayer. The diclofenac-DMPC interactions were clearly dependent on the drug's ionization state. Neutral diclofenac displayed greater affinity for DMPC bilayers than anionic diclofenac. Moreover, the protonated/neutral form of the drug induced more pronounced and/or distinct alterations in the structure of the DMPC bilayer than the deprotonated/ionized form, considering similar membrane concentrations. Therefore, neutral diclofenac-induced changes in the structural properties of the external phospholipid layers of the gastric mucosa may constitute an additional toxicity mechanism of this worldwide-used drug, which shall be considered for the development of safer therapeutic strategies. SIGNIFICANCE STATEMENT: Neutral or anionic diclofenac exerted distinct alterations in phosphatidylcholine bilayers, which are used in this work as models for the protective phospholipid layers of the gastric mucosa. Remarkable changes were induced by neutral diclofenac in the structural properties of the phospholipid bilayer, suggesting that both ionized and neutral states of nonsteroidal anti-inflammatory drugs must be considered to clarify their mechanisms of toxicity and to ultimately develop safer anti-inflammatory drugs.
Assuntos
Anti-Inflamatórios não Esteroides/toxicidade , Diclofenaco/toxicidade , Dimiristoilfosfatidilcolina/química , Mucosa Gástrica/efeitos dos fármacos , Bicamadas Lipídicas/química , Mucosa Gástrica/química , Concentração de Íons de Hidrogênio , Lipossomos/química , Estrutura Molecular , Espalhamento a Baixo Ângulo , Difração de Raios XRESUMO
Cell wall modification is integral to many plant developmental processes where cells need to separate, such as abscission. However, changes in cell wall composition during natural fruit abscission are poorly understood. In olive (Olea europaea L.), some cultivars such as 'Picual' undergo massive natural fruit abscission after fruit ripening. This study investigates the differences in cell wall polysaccharide composition and the localization of pectins and arabinogalactan protein (AGP) in the abscission zone (AZ) during cell separation to understand fruit abscission control in 'Picual' olive. To this end, immunogold labeling employing a suite of monoclonal antibodies to cell wall components (JIM13, LM5, LM6, LM19 and LM20) was investigated in olive fruit AZ. Cell wall polysaccharide extraction revealed that the AZ cell separation is related to the de-esterification and degradation of pectic polysaccharides. Moreover, ultrastructural localization showed that both esterified and unesterified homogalacturonans (HGs) localize mainly in the AZ cell walls, including the middle lamella and tricellular junction zones. Our results indicate that unesterified HGs are likely to contribute to cell separation in the olive fruit AZ. Similarly, immunogold labeling demonstrated a decrease in both galactose-rich and arabinose-rich pectins in AZ cell walls during ripe fruit abscission. In addition, AGPs were localized in the cell wall, plasma membrane and cytoplasm of AZ cells with lower levels of AGPs during ripe fruit abscission. This detailed temporal profile of the cell wall polysaccharide composition, and the pectins and AGP immunolocalization in the olive fruit AZ, offers new insights into cell wall remodeling during ripe fruit abscission.
Assuntos
Parede Celular/ultraestrutura , Frutas/química , Galactanos/ultraestrutura , Mucoproteínas/ultraestrutura , Olea/química , Pectinas/ultraestrutura , Arabinose/metabolismo , Esterificação , Galactose/metabolismo , Proteínas de Plantas/ultraestrutura , Polissacarídeos/ultraestruturaRESUMO
Sustainably made, flexible and biocompatible composites, having environmentally friendly compositions and multifunctional capabilities, are promising materials for several emerging biomedical applications. Here, the development of flexible and multifunctional chitosan-based bionanocomposites with a mixed reduced graphene oxide-iron oxide (rGO-Fe3-xO4) filler is described. The filler is prepared by one-pot synthesis, ensuring good dispersibility of the Fe3-xO4 nanoparticles and rGO within the chitosan matrix during solvent casting. The resulting bionanocomposites present superparamagnetic response at room temperature. The antioxidant activity is 9 times higher than that of pristine chitosan. The mechanical properties of the films can be tuned from elastic (â¼8 MPa) chitosan films to stiff (â¼285 MPa) bionanocomposite films with 50% filler. The magnetic hyperthermia tests showed a temperature increase of 40 °C in 45 s for the 50% rGO-Fe3-xO4 film. Furthermore, the composites have no cytotoxicity to the nontumorigenic (HaCat) cell line, which confirms their biocompatibility and highlights the potential of these materials for biomedical applications, such as hyperthermia treatments.
Assuntos
Antioxidantes/química , Materiais Biocompatíveis/química , Quitosana/química , Hipertermia Induzida , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Compostos Férricos/química , Grafite/química , Humanos , Tamanho da Partícula , Solubilidade , Propriedades de SuperfícieRESUMO
The extracellular polysaccharides produced by cyanobacteria have distinctive characteristics that make them promising for applications ranging from bioremediation to biomedicine. In this study, a sulfated polysaccharide produced by a marine cyanobacterial strain and named cyanoflan was characterized in terms of morphology, chemical composition, and rheological and emulsifying properties. Cyanoflan has a 71 % carbohydrate content, with 11 % of sulfated residues, while the protein account for 4 % of dry weight. The glycosidic-substitution analysis revealed a highly branched complex chemical structure with a large number of sugar residues. The cyanoflan high molecular mass fractions (above 1â¯MDa) and entangled structure is consistent with its high apparent viscosity in aqueous solutions and high emulsifying activity. It showed to be a typical non-Newtonian fluid with pseudoplastic behavior. Altogether, these results confirm that cyanoflan is a versatile carbohydrate polymer that can be used in different biotechnological applications, such as emulsifying/thickening agent in food or cosmetic industries.
Assuntos
Cianobactérias/metabolismo , Emulsificantes/química , Polissacarídeos Bacterianos/química , Óxidos de Enxofre/química , Peso Molecular , Parafina/química , Óleos de Plantas/química , Reologia , ViscosidadeRESUMO
Staphylococcus aureus (S. aureus) is considered by the World Health Organization as a high priority pathogen for which new therapies are needed. This is particularly important for biofilm implant-associated infections once the only available treatment option implies a surgical procedure combined with antibiotic therapy. Consequently, these infections represent an economic burden for Healthcare Systems. A new strategy has emerged to tackle this problem: for small bugs, small particles. Here, we describe how nanotechnology-based systems have been studied to treat S. aureus biofilms. Their features, drawbacks and potentialities to impact the treatment of these infections are highlighted. Furthermore, we also outline biofilm models and assays required for preclinical validation of those nanosystems to smooth the process of clinical translation.
Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Nanotecnologia/métodos , Staphylococcus aureus/efeitos dos fármacos , Animais , Equipamentos e Provisões/microbiologia , Humanos , Camundongos , Testes de Sensibilidade Microbiana , Nanoestruturas , Infecções Relacionadas à Prótese/tratamento farmacológico , Infecções Estafilocócicas/tratamento farmacológicoRESUMO
Marine environments are an enormous source of materials with biological interest, such as sulphated polysaccharides, which have relevant biological activities. In this study the potential of salt pan brine water as an easily accessible source of sulphated polysaccharides was evaluated. This water revealed to have a high quantity of polymeric material, five times more than sea water, mainly composed by highly sulphated polysaccharides. Structural analysis identified a diversity of polysaccharides, namely rhamnans, fucans, mannans, xylomannans, glucuronomannans, galactans, and glucans. All these structures seem to form complexes that are resistant to the salt pan conditions along salt production. These polysaccharides showed in vitro stimulatory activity for B cells, suggesting their potential application in nutraceutical and biomedical fields. Salt pan brine water is a valuable source of environmentally friendly and low-cost available bioactive compounds prone to be exploited.
Assuntos
Adjuvantes Imunológicos/química , Adjuvantes Imunológicos/farmacologia , Polissacarídeos/química , Polissacarídeos/farmacologia , Sais/química , Água do Mar/química , Sulfatos/química , Animais , Linfócitos/efeitos dos fármacos , Linfócitos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Peso MolecularRESUMO
Topotecan is a relatively large, planar, asymmetric and polar molecule with a lactone moiety. In neutral or basic aqueous solutions, this ring opens forming the carboxylate form of Topotecan that is biologically inactive and uncapable of passively cross membranes. Nevertheless, despite this inability to cross membranes at this form, Topotecan may still be able to interact with phospholipid bilayers, disturbing them. In this context, phospholipid models, mimicking normal (DMPC at pHâ¯7.4) and cancer cell lipid membranes (DMPC:DMPS (5:1) at pHâ¯6.5), were used to assess structural modifications upon interaction with Topotecan. Langmuir isotherms of monolayers coupled with Brewster angle microscopy, differential scanning calorimetry of liposomes and X-ray scattering of small and wide angle of stacked multilayers were used as complementary techniques. The overall results show that the interaction of Topotecan with lipid membranes is deeply conditioned by their composition and that Topotecan seems to have a preferential interaction with the glycerol backbone of phosphatidylcholine phospholipids.
Assuntos
Membrana Celular/efeitos dos fármacos , Dimiristoilfosfatidilcolina/química , Membranas Artificiais , Neoplasias/tratamento farmacológico , Inibidores da Topoisomerase I/farmacologia , Topotecan/farmacologia , Animais , Membrana Celular/química , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular , Dimiristoilfosfatidilcolina/metabolismo , Humanos , Modelos Biológicos , Estrutura Molecular , Neoplasias/química , Neoplasias/metabolismo , Fosfatidilcolinas/química , Fosfatidilcolinas/metabolismo , Fosfatidilserinas/química , Fosfatidilserinas/metabolismo , Relação Estrutura-Atividade , Inibidores da Topoisomerase I/química , Inibidores da Topoisomerase I/metabolismo , Topotecan/química , Topotecan/metabolismoRESUMO
The well-known pleiotropic health benefits of green tea are mainly attributed to epigallocatechin-3-gallate (EGCG), a polyphenolic compound from the group of catechins. EGCG's poor stability and intestinal permeability, however, can strongly impair its biological activities. In this work, EGCG-loaded nanostructured lipid carriers (NLC) functionalized with folic acid were optimized through a Box-Behnken design intended to provide an enhanced oral absorption and increased bioavailability of EGCG. Size, zeta potential and encapsulation efficiency (EE) of the produced spherical nanoparticles were evaluated. NLC were further characterized by Differential Scanning Calorimetry (DSC). An in vitro release study in simulated gastric and intestinal fluids was conducted and the storage stability of the nanoparticles was evaluated over a period of 8weeks. The overall results demonstrated the suitability of the developed formulation for the oral delivery of EGCG and its potential for applications in food industry.
Assuntos
Catequina/análogos & derivados , Nanoestruturas/química , Catequina/química , Portadores de Fármacos , Ácido Fólico , Humanos , LipídeosRESUMO
The aggregation of amyloid-ß peptide (Aß) has been linked to the formation of neuritic plaques, which are pathological hallmarks of Alzheimer's disease (AD). Various natural compounds have been suggested as therapeutics for AD. Among these compounds, resveratrol has aroused great interest due to its neuroprotective characteristics. Here, we provide evidence that grape skin and grape seed extracts increase the inhibition effect on Aß aggregation. However, after intravenous injection, resveratrol is rapidly metabolized into both glucuronic acid and sulfate conjugations of the phenolic groups in the liver and intestinal epithelial cells (within less than 2 h), which are then eliminated. In the present study, we show that solid lipid nanoparticles (SLNs) functionalized with an antibody, the anti-transferrin receptor monoclonal antibody (OX26 mAb), can work as a possible carrier to transport the extract to target the brain. Experiments on human brain-like endothelial cells show that the cellular uptake of the OX26 SLNs is substantially more efficient than that of normal SLNs and SLNs functionalized with an unspecific antibody. As a consequence, the transcytosis ability of these different SLNs is higher when functionalized with OX-26.
Assuntos
Doença de Alzheimer/metabolismo , Lipídeos/química , Nanopartículas/química , Extratos Vegetais/administração & dosagem , Extratos Vegetais/química , Estilbenos/administração & dosagem , Vitis/química , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Animais , Barreira Hematoencefálica/metabolismo , Composição de Medicamentos , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Extrato de Sementes de Uva/administração & dosagem , Extrato de Sementes de Uva/química , Imunoconjugados/administração & dosagem , Imunoconjugados/química , Nanopartículas/ultraestrutura , Tamanho da Partícula , Permeabilidade/efeitos dos fármacos , Agregados Proteicos/efeitos dos fármacos , Agregação Patológica de Proteínas/tratamento farmacológico , Agregação Patológica de Proteínas/metabolismo , ResveratrolRESUMO
Chitosan has been studied as a renewable polymer to form edible films allowing the incorporation of functional compounds. The aim of this work was to evaluate the effects in the chitosan films properties of the incorporation of grape pomace extracts: 0.15% of hot water extract (mainly polysaccharides), 0.15 and 0.3% of chloroform extract (wax), and 0.3 and 0.75% of n-hexane extract (oil). The evaluation of the surface morphology revealed that the films with the aqueous extract had the most homogeneous and smoother topography. The incorporation of higher proportion of wax and oil led to changes in mechanical properties of the films, namely lower resistance and stiffness. The chitosan-based films with 0.75% oil demonstrated a 75% decrease of solubility in water, due to their hydrophobicity, as confirmed by the contact angle and surface free energy measurements. The hydrophobic films showed higher antioxidant capacity in organic medium (ABTS and DPPH assays) whereas the most hydrophilic films showed an improvement in FRAP and reducing power assays. Therefore, all the chitosan-based films prepared by incorporation of these grape pomace extracts are promising for food shelf life extension.
Assuntos
Quitosana/química , Extratos Vegetais/química , Vitis/química , Antioxidantes/química , Hexanos/químicaRESUMO
A novel pH-sensitive drug delivery system based on functionalized silica nanotubes was developed for the incorporation of non-steroidal anti-inflammatory drugs (NSAIDs), aimed at a tailored drug release in acidic conditions characteristic of inflamed tissues. Silica nanotubes (SNTs) were synthesized by a nanoporous alumina template assisted sol-gel method. Inner surfaces were physically and chemically modified to improve both the functionalization and subsequent incorporation of the drug. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM) were used to characterize the designed nanocarriers and their functionalization. To achieve the highest degree of functionalization, three types of aminosilanes were tested and calcination conditions were optimized. APTES was shown to be the most effective aminosilane regarding the functionalization of the SNTs' inner surface and an adequate calcination temperature (220°C) was found to attain mechanical stability without compromising functionalization efficiency. Finally, the incorporation of naproxen into the nanotubes was accessed by fluorescence measurements and drug release studies were performed, revealing that the electrostatic linkage ensures effective release of the drug in the acidic pH typical of inflamed cells, while maintaining the SNT-drug conjugates stable at the typical bloodstream pH.
Assuntos
Anti-Inflamatórios não Esteroides/química , Portadores de Fármacos/síntese química , Nanotubos/química , Naproxeno/química , Dióxido de Silício/química , Óxido de Alumínio/química , Anti-Inflamatórios não Esteroides/metabolismo , Composição de Medicamentos , Humanos , Concentração de Íons de Hidrogênio , Cinética , Microscopia Eletrônica de Varredura , Nanotubos/ultraestrutura , Naproxeno/metabolismo , Propilaminas , Silanos/química , Espectrometria de Fluorescência , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática , TemperaturaRESUMO
Ageing of the endocrine system (endocrinosenescence) has been closely related to immunosenescence. Dehydroepiandrosterone sulphate (DHEAS), a steroid hormone produced by the adrenals with reported enhancing immunomodulatory properties, consistently decline during ageing in parallel to detrimental increase in peripheral glucocorticoids. We investigated here the adjuvant effects of DHEAS during intraperitoneal immunization to Mycobacterium tuberculosis heat shock protein 70 (mycHSP70) in old (24 months) as well as young (3 months) BALB/c mice. Both young and old mice had significantly higher Immunoglobulin G (IgG) levels following immunization. Young mice co-immunized with mycHSP70-DHEAS presented an early increase in specific IgG levels and showed increased Interferon-gamma production compared to old mice. Also, T cells of immunized young animals were consistently more resistant to the immunosuppressive effects of glucocorticoids and to DHEAS. DHEAS was not effective in modulating antigen-specific T-cell proliferation, Interleukin-2 production or percentage of recent activated T-cell subsets (CD4 + CD69 + and CD8 + CD69 +). Our data further indicate mycHSP70 as a putative good antigen in vaccine to tuberculosis. Our data also suggest that DHEAS produced adjuvant effects upon humoral and some cellular immune responses of young, but not old mice and indicate that immunization with DHEAS is capable of changing T-cell responses to steroids.