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1.
Int J Biol Macromol ; 257(Pt 1): 128612, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38070366

RESUMEN

Eucalypt kraft lignin isolated in a LignoBoost™ pilot plant was characterized by GC-MS, ICP-OES, DSC, HPSEC, 31P NMR, and HSQC 2D-NMR to be used without any further processing to produce lignin nanoparticles (LNPs) by nanoprecipitation. Tetrahydrofuran (THF) was used as a solvent, and water as a non-solvent. Microscopic analysis (TEM) showed that LNPs were regularly spherical with some hollow particles dispersed in-between, and sizes were tunable by changing the solvent dripping rate onto the non-solvent. LNP particle sizes had a bimodal distribution, with the largest population having an average apparent hydrodynamic diameter ranging from 105.6 to 75.6 nm. Colloidal dispersions of LNPs in water presented good stability in different dilutions without significant size changes upon storage at pH close to neutral for as long as 45 days. Zeta potentials around -40 mV were obtained for LNP suspensions at pH ranging from 7 to 9. The high carbohydrate content (circa 10 % on a dry basis, mostly xylans) of the lignin precursor did not interfere in LNP formation, whose antioxidant activity was expressive as demonstrated by the ABTS assay at pH 7.4, with an EC50 of 4.04 µg mL-1. Also, the Trolox® equivalent antioxidant capacity (TEAC) of LNPs reached 1.90 after 40 min reaction time.


Asunto(s)
Antioxidantes , Nanopartículas , Antioxidantes/química , Lignina/química , Nanopartículas/química , Solventes , Agua
2.
J Appl Toxicol ; 42(12): 2016-2029, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35883269

RESUMEN

Aluminum chlorohydrate (ACH) is a major aerosol component frequently used as the active ingredient in antiperspirants, and in vivo studies have raised a concern about its inhalation toxicity. Still, few studies have addressed its effects on the human respiratory tract. Therefore, we developed a study on ACH inhalation toxicity using an in vitro human alveolar cell model (A549 cells) with molecular and cellular markers of oxidative stress, immunotoxicity, and epigenetic changes. The chemical characterization of ACH suspensions indicated particle instability and aggregation; however, side-scatter analysis demonstrated significant particle uptake in cells exposed to ACH. Exposure of A549 cells to non-cytotoxic concentrations of ACH (0.25, 0.5, and 1 mg/ml) showed that ACH induced reactive oxygen species. Moreover, ACH upregulated TNF, IL6, IL8, and IL1A genes, but not the lncRNAs NEAT1 and MALAT1. Finally, no alterations on the global DNA methylation pattern (5-methylcytosine and 5-hydroxymethylcytosine) or the phosphorylation of histone H2AX (γ-H2AX) were observed. Our data suggest that ACH may induce oxidative stress and inflammation on alveolar cells, and A549 cells may be useful to identify cellular and molecular events that may be associated with adverse effects on the lungs. Still, further research is needed to ensure the inhalation safety of ACH.


Asunto(s)
Aluminio , Cosméticos , Humanos , Administración por Inhalación , Aerosoles , Vehículos Farmacéuticos , Exposición por Inhalación/efectos adversos
3.
Cell Death Dis ; 12(2): 158, 2021 02 05.
Artículo en Inglés | MEDLINE | ID: mdl-33547278

RESUMEN

Uric acid (UA), a product of purine nucleotide degradation able to initiate an immune response, represents a breakpoint in the evolutionary history of humans, when uricase, the enzyme required for UA cleavage, was lost. Despite being inert in human cells, UA in its soluble form (sUA) can increase the level of interleukin-1ß (IL-1ß) in murine macrophages. We, therefore, hypothesized that the recognition of sUA is achieved by the Naip1-Nlrp3 inflammasome platform. Through structural modelling predictions and transcriptome and functional analyses, we found that murine Naip1 expression in human macrophages induces IL-1ß expression, fatty acid production and an inflammation-related response upon sUA stimulation, a process reversed by the pharmacological and genetic inhibition of Nlrp3. Moreover, molecular interaction experiments showed that Naip1 directly recognizes sUA. Accordingly, Naip may be the sUA receptor lost through the human evolutionary process, and a better understanding of its recognition may lead to novel anti-hyperuricaemia therapies.


Asunto(s)
Inflamasomas/metabolismo , Macrófagos/efectos de los fármacos , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Proteína Inhibidora de la Apoptosis Neuronal/metabolismo , Ácido Úrico/farmacología , Animales , Ácidos Grasos/metabolismo , Humanos , Inflamasomas/genética , Inflamasomas/inmunología , Interleucina-1beta/metabolismo , Macaca mulatta , Macrófagos/inmunología , Macrófagos/metabolismo , Ratones Endogámicos C57BL , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Proteína Inhibidora de la Apoptosis Neuronal/genética , Unión Proteica , Células THP-1 , Ácido Úrico/metabolismo
4.
Carbohydr Polym ; 247: 116716, 2020 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-32829843

RESUMEN

The production of a chitin-like exopolysaccharide (EPS) was optimized through experimental design methods, evaluating the influence of urea, phosphate, and glucose. Under optimized conditions, up to 1.51 g/L was produced and its physicochemical characteristics were evaluated by chromatography, NMR, and FTIR spectroscopy, and rheological techniques. The results showed a homogeneous EPS (Mw 4.9 × 105 g mol-1) composed of chitin, linear polymer of ß-(1→4)-linked N-acetyl-d-glucosamine residues. The acetylation degree as determined by 13C CP-MAS NMR spectroscopy was over 90 %. The EPS biological activities, such as antioxidant effect and antitumor properties, were evaluated. To the best of our knowledge, this is the first study on the production of a new alternative of extracellular chitin-like polysaccharide with promising bioactive properties from the filamentous fungus M. alpina.


Asunto(s)
Antineoplásicos/farmacología , Antioxidantes/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Quitina/química , Fermentación , Mortierella/metabolismo , Polisacáridos/farmacología , Antineoplásicos/química , Antioxidantes/química , Neoplasias de la Mama/patología , Femenino , Glucosa/metabolismo , Humanos , Polisacáridos/química , Polisacáridos/aislamiento & purificación , Células Tumorales Cultivadas
5.
J Pharm Sci ; 109(7): 2294-2301, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32311369

RESUMEN

This work describes the development of polysaccharide-coated liposomes to modulate the delivery of epidermal growth factor (EGF), with the aim to produce different EGF release profiles depending on the milieu of infected wounds. For this purpose, cationic liposomes were coated with one layer of sodium alginate (ALG) followed by one layer of chitosan (CHI) using the layer-by-layer (LbL) technique. The coated liposomes exhibited apparent hydrodynamic diameters of 278 ± 36 and 216 ± 96 nm for Lip-ALG and Lip-ALG-CHI, respectively. Thus, it appears that adding the CHI layer compacted the Lip-ALG one. The incorporation efficiency of EGF was a maximum of 55% for liposomes with a polymeric coating. In vitro release experiments showed that Lip-ALG-CHI exhibits a higher release rate constant under acidic pH conditions, resembling those of infected tissue. Using an ex vivo model of EGF release in porcine ear skin, these liposomes were found to accumulate in the epidermis. Thus, coated liposomes could represent a local EGF delivery mechanism to promote healing.


Asunto(s)
Quitosano , Liposomas , Alginatos , Animales , Factor de Crecimiento Epidérmico , Piel , Porcinos
6.
Carbohydr Polym ; 223: 115083, 2019 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-31426988

RESUMEN

The influence of Na2SO4 as a kosmotropic salt on the thermogelation of xyloglucan (XG) solutions was measured by rheology. The gelation occurred at lower temperatures and shorter times when the salt concentration was increased above 0.5 mol.L-1. For Na2SO4 concentrations equal to 1 mol.L-1, a not thermoreversible elastic hydrogel was obtained. Salts containing various types of anions were used, and it was observed that SO42-, HPO42- and H2PO4- promoted the formation of a gelled network. The gel structure was observed using confocal laser scanning microscopy and scanning electron microscopy. In XG containing SO42 at 1 mol.L-1aggregates and gels were formed by interconnected sub-micrometer XG particles. Increasing the concentration of SO42- led to conformation changes in the XG, from a twisted/helical to an extended/flat conformation, as observed using circular dichroism. The naturally occurring hydrophobic sequences promoted an economically feasible XG gelling that may produce thermo and kosmo-sensitive hydrogels.

7.
J Ethnopharmacol ; 244: 112133, 2019 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-31377260

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: The leaves of Eugenia species are widely used in popular medicine to treat several diseases, such as arthritis, rheumatism and diabetes. Eugenia umbelliflora O. Berg is popularly known in Brazil as "baguaçu", name also conferred to Eugenia jambolana probably due to their apparent similarity. Although the popular use scientifically proved of E. jambolana as anti-diabetes and also as anti-inflammatory, there are only two scientific studies demonstrating anti-ulcer and bactericide activities of E. umbelliflora leaves extract, without reference to its possible anti-inflammatory activity. AIM OF THE STUDY: The aim of this study was to show the anti-oxidant and anti-inflammatory activity of the methanol extract obtained from E. umbelliflora leaves (EuL) using in vitro and in vivo protocols. MATERIALS AND METHODS: The total phenolic content was evaluated using the folin-Ciocalteu colorimetric method and phloroglucinols content by HPLC. The anti-oxidant activity was evaluated by ORAC, ABTS•+, DPPH, and metal chelation methods. The anti-inflammatory activity was investigated using carrageenan-induced inflammation in the subcutaneous tissue of male Swiss mice orally pre-treated with the EuL (0.3, 1 or 3 mg/kg). The leukocyte influx (optical microscopy) and secretion of chemical mediators (TNF, IL-6, IL-1ß and CXCL1, by enzyme-linked immunosorbent assay) were quantified in the inflamed exudate. Histological analysis of the pouches was also performed. The anti-hypersensitive activity was investigated using carrageenan-induced mechanical hypersensitivity and mice were then evaluated using the von Frey filaments. The Open Field test was used to evaluate possible interference of adverse effect of EuL on locomotor activity that could lead to misinterpretation of the hypersensitivity evaluation. RESULTS: The EuL demonstrated important and moderate reducing capacity on ABTS•+ and DPPH assays, respectively, but with slight activity in ORAC test. It reflects low protection against cell damage. The EuL also presented 30% of phenolic compounds. The phloroglucinols content of EuL was 25.9 mg/g, 18.4 mg/g and 16.6 mg/g of eugenial C, eugenial D and eugenial E, respectively. The in vivo analysis of the inflammatory exudate of EuL-treated mice demonstrated reduction in the polymorphonuclear cells (PMN) migration to the inflamed tissue, as well as the reduction of the pro-inflammatory cytokine IL-1ß. Histologically, it was observed evident decrease in the oedema, formed essentially by non-haemorrhagic fibrin exudate, as well as PMN infiltrate, when compared with control mice injected with carrageenan. Furthermore, the extract also presented effective reduction of the mechanical hypersensitivity induced by carrageenan without any interference in animal's locomotor and exploratory activity. CONCLUSIONS: Together, the results herein obtained show that EuL presented anti-inflammatory activity by decreasing the influx of PMN to the inflamed tissue, as well as the cytokine IL-1ß level. This anti-inflammatory activity was also accompanied by significant anti-hypersensitive effect. The effects presented by EuL seem not to be correlated with an antioxidant activity. However other extract chemical compounds could be responsible for its important anti-inflammatory effects.


Asunto(s)
Antiinflamatorios/uso terapéutico , Antioxidantes/uso terapéutico , Edema/tratamiento farmacológico , Eugenia , Extractos Vegetales/uso terapéutico , Animales , Antiinflamatorios/química , Antioxidantes/química , Carragenina , Citocinas/inmunología , Edema/inducido químicamente , Edema/inmunología , Hipersensibilidad/tratamiento farmacológico , Hipersensibilidad/inmunología , Locomoción/efectos de los fármacos , Masculino , Ratones , Fitoquímicos/análisis , Fitoquímicos/uso terapéutico , Extractos Vegetales/química , Hojas de la Planta
8.
Int J Biol Macromol ; 130: 622-626, 2019 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-30831162

RESUMEN

The mechanical pretreatments intensities on characteristics of cellulose nanocrystals (CNC) prior to acid hydrolysis was evaluated. The cellulose was submitted to mechanical pretreatment as: magnetic stirring (CNCst), blending (CNCbl) or grinding by 20 (CNC20x) and 40 (CNC40x) passages in a super mass colloid mill. Then, all samples were submitted to H2SO4 hydrolysis and the CNC were evaluated by total mass yield (TMY%), rheological behavior, size distribution for width/length (WD), crystallinity index (CI%), OSO3- substitution degree (SD) and zeta potential (ζ). After hydrolysis samples exhibited the same SD (190 ±â€¯5 mMol·kg-1), ζ (-55 ±â€¯3 mV) and CI% (65 ±â€¯2), differing only in TMY% and WD. The CNCst showed TMY% of 85%, WD of 8 ±â€¯5 nm and 100-800 nm, with presence of cellulose nanofibers (CNF), suggesting incomplete hydrolysis. The CNCbl and CNC20x revealed TMY% of 65 ±â€¯1, but differed in WD of 8 ±â€¯5 nm and 300 ±â€¯200 nm and 8 ±â€¯5 nm and 200 ±â€¯170 nm, respectively. The results showed that the grinding mechanical pretreatment is mandatory for CNF isolation, but not for CNC. Stability profile after the hydrolytic procedure, CI%, morphology and similar character generated CNC with adequate features and good yield, by simple mechanical stirring or blending, reducing the production's cost and allowing industrial-scale production.


Asunto(s)
Celulosa/química , Celulosa/aislamiento & purificación , Nanopartículas/química , Ácidos Sulfúricos/química , Celulosa/análisis , Fraccionamiento Químico/métodos , Hidrólisis , Microscopía de Fuerza Atómica , Nanopartículas/análisis , Análisis Espectral , Viscosidad
9.
Food Res Int ; 116: 12-19, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30716906

RESUMEN

Amazonian plants possess high amounts of little-explored lipid compounds. Chemical parameters and lipophilic compounds present in twelve oils and fats from different Amazonian plants were characterized. The fatty acids identified reveal saturated fats, such as babassu oil and muru-muru fat (rich in lauric acid), ucuhuba fat (myristic acid), and bacuri fat (palmitic acid). Buriti, pracaxi, and patawa oils showed high oleic acid content. Passion fruit seed and Brazil nut oils had high levels of the polyunsaturated fatty acids rich in linoleic acid. The oleaginous plants had high unsaturation degree and high content of medium-length-chain fatty acids due to high values of iodine, saponification, and peroxide. For methyl tocols and total carotenes, a simultaneous determination method was used and revealed high levels of these vitamins in buriti oil. No previous work in the literature has described all these parameters in Amazonian oils and fats, especially regarding plant species such as bacuri, cupuassu, and ucuhuba. These results provide information on oils and fats that could be used as alternative sources of raw material for the food and pharmaceutics industries.


Asunto(s)
Ácidos Grasos/análisis , Aceites de Plantas/química , Bertholletia/química , Carotenoides/análisis , Ácidos Grasos Insaturados/análisis , Ácidos Láuricos , Ácido Linoleico/análisis , Ácido Oléico/análisis , Ácido Palmítico/análisis , Aceites de Plantas/análisis , Plantas/química , Semillas/química , Tocoferoles/análisis
10.
Talanta ; 187: 165-171, 2018 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-29853030

RESUMEN

The biotechnological evolution towards the development of antigens to detect leprosy has been progressing. However, the identification of leprosy in paucibacillary patients, based solely on the antigen-antibody interaction still remains a challenge. The complexity of clinical manifestations requires innovative approaches to improve the sensitivity of assays to detect leprosy before the onset of symptoms, thus avoiding disabilities and contributing, indirectly, to reduce transmission. In this study, the strategies employed for early leprosy diagnosis were: i. using a phage-displayed mimotope (APDDPAWQNIFNLRR) which mimics an immunodominant sequence (PPNDPAWQRNDPILQ) of an antigen of Mycobacterium leprae known as Ag85B; ii. engineering the mimotope by adding a C-terminal flexible spacer (SGSG-C); iii. conjugating the mimotope to a carrier protein to provide better exposure to antibodies; iv. amplifying the signal using biotin-streptavidin detection system in an ELISA; and v. coating the optimized mimotope on a quartz crystal microbalance (QCM) sensor for label-free biosensing. The ELISA sensitivity increased up to 91.7% irrespective of the immunological profile of the 132 patients assayed. By using comparative modeling, the M. tuberculosis Ag85B was employed as a template to ascertain which features make the mimotope a good antigen in terms of its specificity. For the first time, a sensitive QCM-based immunosensor to detect anti M. leprae antibodies in human serum was used. M. leprae antibodies could also be detected in the sera of paucibacillary patients; thus, the use of a mimotope-derived synthetic peptide as bait for antibodies in a novel analytical label-free immunoassay for leprosy diagnosis exhibits great potential.


Asunto(s)
Técnicas Biosensibles , Inmunoensayo , Lepra/diagnóstico , Mycobacterium leprae/aislamiento & purificación , Tecnicas de Microbalanza del Cristal de Cuarzo , Adulto , Animales , Biomarcadores/análisis , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C
11.
Carbohydr Polym ; 185: 63-72, 2018 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-29421061

RESUMEN

To propose a novel modeling of aflatoxin immunization and surrogate toxin conjugate from AFB1 vaccines, an immunogen based on the mimotope, (i.e. a peptide-displayed phage that mimics aflatoxins epitope without toxin hazards) was designed. The recombinant phage 3P30 was identified by phage display technology and exhibited the ability to bind, dose dependent, specifically to its cognate target - anti-AFB1 antibody. In immunization assay, the phage-displayed mimotope and its peptide chemically synthesized were able to induce specific anti-AFB1 antibodies, indicating the proof of concept for aflatoxin mimicry. Furthermore, the phage 3P30 was homogeneously coated with chitosan, which also provided a tridimensional matrix network for mucosal delivery. After intranasal immunization, chitosan coated phages improved specific immunogenicity compared to the free antigen. It can be concluded that affinity-selected phage may contribute to the rational design of epitope-based vaccines in a prospectus for the control of aflatoxins and possibly other mycotoxins, and that chitosan coating improved the vectorization of the vaccine by the mucosal route.


Asunto(s)
Aflatoxina B1/inmunología , Bacteriófagos/química , Quitosano/análogos & derivados , Nanopartículas/química , Vacunas/química , Animales , Bacteriófagos/inmunología , Femenino , Ratones , Biblioteca de Péptidos , Vacunas/inmunología
12.
Carbohydr Polym ; 174: 517-523, 2017 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-28821099

RESUMEN

Gelation kinetics of aqueous solutions of xyloglucan (XG) extracted from H. courbaril seeds were investigated, in-situ, during enzymatic removal of galactose units by oscillatory shear rheological measurements, at different XG and enzyme (ß-galactosidase) concentrations. Increasing the enzyme concentration (Cenz) led to an increase of the gelation rate. Master curves of the evolution of the storage shear modulus at different Cenz could be formed by time-Cenz superposition showing that Cenz influenced the kinetics, but not the gelation process and the final gel stiffness. The behaviour of gels formed by XG with different molar mass (Mw), prepared by endoglucanase hydrolysis, was evaluated as a function of the temperature. It was found that cooling led to a decrease of the crosslink density causing a decrease of the gel stiffness. The decrease of the crosslink density was sufficient to depercolate the network formed by relatively small XG with Mw=105gmol-1, but gels formed by XG with Mw≥8×105gmol-1 persisted down to 10°C. It is shown that the melting temperature and the gel stiffness at high temperatures can be controlled independently by varying the molar mass and the concentration of XG chains.

13.
Int J Biol Macromol ; 104(Pt A): 97-106, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28587970

RESUMEN

Bacterial cellulose (BC) derived materials represents major advances to the current regenerative and diagnostic medicine. BC is a highly pure, biocompatible and versatile material that can be utilized in several applications - individually or in the combination with different components (e.g. biopolymers and nanoparticles) - to provide structural organization and flexible matrixes to distinct finalities. The wide application and importance of BC is described by its common utilization as skin repair treatments in cases of burns, wounds and ulcers. BC membranes accelerate the process of epithelialization and avoid infections. Furthermore, BC biocomposites exhibit the potential to regulate cell adhesion, an important characteristic to scaffolds and grafts; ultra-thin films of BC might be also utilized in the development of diagnostic sensors for its capability in immobilizing several antigens. Therefore, the growing interest in BC derived materials establishes it as a great promise to enhance the quality and functionalities of the current generation of biomedical materials.


Asunto(s)
Bacterias , Materiales Biocompatibles , Celulosa , Bacterias/metabolismo , Materiales Biocompatibles/química , Materiales Biocompatibles/metabolismo , Materiales Biocompatibles/farmacología , Celulosa/biosíntesis , Celulosa/química , Celulosa/farmacología , Diagnóstico , Humanos , Medicina Regenerativa
14.
Regul Toxicol Pharmacol ; 86: 93-100, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28257850

RESUMEN

We investigated the hepatoprotective effect of methanolic extract from Maytenus robusta leaves in mice and HepG2 cells. The administration of CCl4 in mice promoted a deep destruction of the histological lobular structure and increased the alanine aminotransferase (ALT) serum levels by 46.25% compared with the control group (p < 0.05). The M. robusta extract reduced the hepatic histological changes and normalization the ALT levels. The antioxidant effect of M. robusta in liver tissue promoted the reduction in 31.5% on lipoperoxides levels (p < 0.05), increased by 101.5% the reduced glutathione content (p < 0.05) and increased the activity of superoxide dismutase, catalase, and glutathione-S-transferase by 21.3% (p < 0.05), 49.3% (p < 0.05), and 27.6% (p < 0.05), respectively, compared with the vehicle group. Moreover, the extract reduced hepatic inflammation by diminishing myeloperoxidase activity, TNF and interleukin-6 levels by 29.4% (p < 0.05), 46.1% (p < 0.01), and 59.5% (p < 0.0001), respectively, compared with the vehicle group. The viability of HepG2 cells after incubation with CCl4 was 29.56± 3.07%, whereas the extract (300 µg/mL) restored the viability to 65.27± 8.75% and aspartate aminotransferase levels to 41.82 ± 4.41 U/L. The extract scavenged DPPH (IC50 = 14.44 µg/mL) and ABTS (IC50 = 3.00 µg/mL) radicals and did not produce acute toxicity in mice at 2000 mg/kg. In conclusion, was confirmed the hepatoprotective potential of M. robusta by its antioxidant effects.


Asunto(s)
Antioxidantes/farmacología , Enfermedad Hepática Inducida por Sustancias y Drogas/prevención & control , Hígado/efectos de los fármacos , Maytenus/química , Extractos Vegetales/farmacología , Hojas de la Planta/química , Sustancias Protectoras/farmacología , Animales , Tetracloruro de Carbono/toxicidad , Supervivencia Celular/efectos de los fármacos , Células Hep G2/efectos de los fármacos , Humanos , Ratones
15.
Biosens Bioelectron ; 92: 47-53, 2017 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-28187298

RESUMEN

Low-cost piezoelectric devices, such as simple frequency monitoring quartz crystal microbalance (QCM) devices, have good clinical utility as fast diagnostic tools for the detection of several diseases. However, unspecific antigen recognition, poor molecular probe adsorption and the need for sample dilution are still common drawbacks that hinder their use in routine diagnosis. In this work, piezoelectric sensors were previously coated with thin films of bacterial cellulose nanocrystals (CN) to provide a more sensitive and adapted interface for the attachment of monoclonal immunoglobulin G (IgGNS1) and to favor specific detection of non-structural protein 1 (NS1) of dengue fever. The assembly of the immunochip surface was analyzed by atomic force microscopy (AFM) and the NS1 detection was followed by quartz crystal microbalance with (QCM-D) and without energy dissipation monitoring (QCM). The CN surface was able to immobilize 2.30±0.5mgm-2 of IgGNS1, as confirmed by AFM topography and phase images along with QCM-D. The system was able to detect the NS1 protein in serum with only 10-fold dilution in the range of 0.01-10µgmL-1 by both QCM and QCM-D. The limits of detection of the two devices were 0.1µgmL-1 for QCM-D and 0.32µgmL-1 for QCM. As a result, QCM-D and QCM apparatuses can be used to follow NS1 recognition and have good potential for more sensitive, fast and/or less expensive diagnostic assays for dengue.


Asunto(s)
Virus del Dengue/aislamiento & purificación , Dengue/diagnóstico , Nanopartículas/química , Polisacáridos Bacterianos/química , Tecnicas de Microbalanza del Cristal de Cuarzo/instrumentación , Proteínas no Estructurales Virales/sangre , Anticuerpos Inmovilizados/química , Bacterias/química , Técnicas Biosensibles/instrumentación , Celulosa/química , Dengue/sangre , Dengue/virología , Diseño de Equipo , Humanos , Inmunoensayo/instrumentación , Dispositivos Laboratorio en un Chip , Nanopartículas/ultraestructura , Proteínas no Estructurales Virales/análisis
16.
Carbohydr Polym ; 153: 169-175, 2016 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-27561484

RESUMEN

The stability of perfluorinated microvesicles is mainly determined by the presence of interfacial materials and their ability to hinder the gas component diffusibility into the bloodstream. The goal of this study is to increase the persistence of the gaseous-core by introducing chitosan-coated 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) microvesicles, reducing gas diffusion from microvesicles, and increasing for a long time ultrasonic signals. Our hypothesis was based on the irreversible adhesion of chitosan towards DSPC head groups observed in thin-films models. This affinity enhanced the stabilization of gaseous-core microvesicles, in which the polysaccharide effectively reduced the phospholipid phase transition enthalpy from 383±5.5Jmg(-1) for plain to 150±9.7Jmg(-1) for chitosan-coated microvesicles, providing a more stable structure that diminished the gaseous component lost and provided the persistence of intense (19)F-NMR signals after 48h, twice as long compared to plain samples. As a result, stronger and long-lasting ultrasonic signals were produced by the more stable chitosan-containing microvesicles, thus, presenting great potential to increase the diagnostic and therapeutic applications of perfluorocarbon carries.


Asunto(s)
Quitosano/química , Medios de Contraste/química , Fluorocarburos/química , Microburbujas , Fosfatidilcolinas/química , Fosfolípidos/química , Solubilidad , Ultrasonografía
17.
Carbohydr Polym ; 153: 371-378, 2016 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-27561508

RESUMEN

Guar (GG) and locust bean (LBG) galactomannans (GMs) oxidation at C-6 was performed with catalyst TEMPO, in which the reaction progress was monitored by consume of NaOH solution. The products were characterized by spectroscopic analysis, infrared, and (1)H-nuclear magnetic resonance, confirming the presence of aldehydes groups as intermediate of reaction to carboxylic acid. From high performance anion exchange chromatography with pulsed amperometric detection Man/Gal molar ratio was determined and demonstrated a preference to oxidize Man during the reaction on both GMs, following a first order kinetics of oxidation. The comparative macromolecular behavior of native and oxidized GMs was obtained through the analysis by high performance size exclusion chromatography, and the persistence length (Lp) was 6nm and 4nm to native LBG and GG, respectively. A more accessible OH-6 at mannose residue in LBG could be related with a two times faster reaction than GG. The selective oxidation with catalyst TEMPO proved to be efficient to increase the flexibility of the GMs during oxidation. Short reaction time and ß-elimination process were mainly observed to LBG, probably due to a more favorable oxidation access to the polysaccharide main chain.

18.
Int J Biol Macromol ; 92: 357-361, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27426701

RESUMEN

Core-shell particles were formed by mixing in aqueous solution the neutral polysaccharide xyloglucan (XG) with microgels. The last one was obtained by heating the whey protein ß-lactoglobulin (ß-LG) in the presence of CaCl2. XG adsorbed spontaneously unto the microgels at pH<5.6. The amount of bound XG per protein was determined using a combination of centrifugation and size exclusion chromatography. It increased linearly with increasing XG concentration. The fraction of XG that adsorbed increased with decreasing pH. The formation of the XG shell inhibited large scale flocculation of the particles, that causes precipitation for naked microgels, close to their isoionic point. The thickness of the XG shell was estimated by measurement of the hydrodynamic radius using dynamic light scattering. The extent of binding depended on the pH history during mixing showing that the protein/XG complex was not in thermodynamic equilibrium.


Asunto(s)
Geles/química , Glucanos/química , Lactoglobulinas/química , Xilanos/química , Cromatografía en Gel , Concentración de Iones de Hidrógeno , Suspensiones , Temperatura
19.
Carbohydr Polym ; 140: 129-35, 2016 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-26876836

RESUMEN

A three-dimensional layer-by-layer (LbL) structure composed by xanthan and galactomannan biopolymers over dioctadecyldimethylammonium bromide (DODAB) liposome template was proposed and characterized for protein drug delivery. The polymers and the surfactant interaction were sufficiently strong to create a LbL structure up to 8 layers, evaluated using quartz crystal microbalance (QCM) and zeta potential analysis. The polymer-liposome binding enthalpy was determined by isothermal titration calorimetry (ITC). The bilayer of biopolymer-coated liposomes with diameters of 165 (±15)nm, measured by dynamic light scattering (DLS), and ζ-potential of -4 (±13)mV. These bilayer-coated nanoparticles increased up to 5 times the sustained release of epidermal growth factor (EGF) at a first order rate of 0.005min(-1). This system could be useful for improving the release profile of low-stability drugs like EGF.


Asunto(s)
Factor de Crecimiento Epidérmico/administración & dosificación , Factor de Crecimiento Epidérmico/química , Liposomas/química , Mananos/química , Polisacáridos Bacterianos/química , Preparaciones de Acción Retardada , Liberación de Fármacos , Galactosa/análogos & derivados , Cinética , Compuestos de Amonio Cuaternario/química
20.
Int J Biol Macromol ; 81: 461-6, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26297307

RESUMEN

Hydrolysis of xyloglucan from Tamarindus indica and Hymenaea courbaril seeds with endoglucanase (EGII), which randomly breaks the (1→4)-linked ß-glycosidic bonds of the polymer chain, was monitored in real time using time-dependent viscometry analysis (TDV). For both samples there was a decrease in the intrinsic viscosity ([η]), viscosity average molar mass (Mv), radius de gyration (Rg) and persistence length (Lp) immediately after the addition of the enzyme. It was observed the formation of oligosaccharides and oligomers composed of ∼2 units, up to 140min. Galactose-containing side chains two positions away from the non-substituted glucose, modulated the action of EGII, and the complete hydrolysis of the XG oligomers occurred after 24h. The results demonstrate for the first time the real-time degradation of xyloglucan as well the macromolecular and oligosaccharide composition during the EGII hydrolysis process.


Asunto(s)
Celulasa/química , Glucanos/química , Xilanos/química , Cromatografía , Hidrólisis , Factores de Tiempo , Viscosidad
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