Multiplex immunoassay for inflammatory proteins quantification in saliva – a methodologic approach

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Development and characterization of hydrogels based on natural polysaccharides : policaju and chitosan

The development of hydrogels based on natural polysaccharides was investigated by preparing mixtures of policaju/chitosan at weight ratios of 1:4 and 2:3. Utilizing dynamic light scattering (DLS) techniques for these mixtures, an increase on the hydrodynamic particle radius was observed varying their pH from 3.0 to 12.0. Furthermore, a reduction of ζ-potential was also observed for the same pH interval. Following rounds of drying/hydration cycles at a specific pH value, hydrogel matrices were formed. The pore size distribution of these formed hydrogels was examined using scanning electron microscopy. Further FT-IR analyses confirmed a physical interaction between the polysaccharides policaju and chitosan. Swelling experiments revealed water uptake values, after 24h of immersion in water, close to 270% for 1:4, and 320% for 2:3 hydrogels. Finally, rheological measurements were then conducted in order to confirm hydrogel viscoelastic features. These results indicate a promising road to biomaterials fabrication and biomedical applications. Copyright © 2014 Elsevier B.V. All rights reserved.Paulo A.G. Soares is a recipient of a scholarship from Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) and the author Ana I. Bourbon is a recipient of a fellowship from the Fundacao para a Ciencia e Tecnologia, POPH-QREN and FSE (FCT, Portugal) through grant SFRH/BD/73178/2010. Maria G. Carneiro-da-Cunha, Maria T.S. Correia, Cesar AS, Andrade and Adalberto Pessoa Jr express their gratitude to the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) for research grants. The authors are grateful to the Centro de Tecnologias Estrategicas do Nordeste (CETENE) of the Ministerio da Ciencia e Tecnologia for technical assistance and the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES/PROCAD) for financial suppor

Quercetin-loaded lecithin/chitosan nanoparticles for functional food applications

This study aimed at the encapsulation of quercetin into lecithin/chitosan nanoparticles using the electrostatic self-assembly technique, followed by evaluation of their functionality (antioxidant activity) and stability at different environmental conditions. These nanoparticles were characterized in terms of: average size, morphology, zeta potential, encapsulation efficiency, loading, and spectroscopic characteristics. Quercetin has been successfully encapsulated in lecithin/chitosan nanoparticles with an efficiency of 96.13 ± 0.44 %. Nanoparticles presented a spherical morphology with an average size of 168.58 ± 20.94 nm and a zeta potential of 56.46 ± 1.94 mV. Stability studies showed that nanoparticles are stable to temperatures ranging between 5 and 70 °C and a pH variation from 3.3 to 5.0. Moreover, encapsulated quercetin showed improved antioxidant properties when compared to free-quercetin. Our results suggest that quercetin-loaded lecithin/chitosan nanoparticles can be used in the manufacture of functional foods.Author Marthyna Pessoa de Souza thanks Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES/PDEE-Brazil) and Fundacao de Amparo a Ciencia e Tecnologia do Estado de Pernambuco (FACEPE, Brazil) for granting her scholarships. Miguel A. Cerqueira is recipient of a fellowship from the Fundacao para a Ciencia e Tecnologia (SFRH/BPD/72753/2010, FCT, POPH-QREN, and FSE Portugal). This research was financially supported by research grants and fellowships from the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), as well as the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) and Fundacao de Amparo a Ciencia e Tecnologia do Estado de Pernambuco (FACEPE).The support of EU Cost Actions FA0904 and FA1001 is gratefully acknowledged

Molecular fragmentation of wheat-germ agglutinin induced by food irradiation reduces its allergenicity in sensitised mice

WGA, an agglutinin from wheat germ which is largely responsible for many of wheat's allergies, was used as a model to investigate the action of ionising radiation on WGA's anti-nutritive effects in sensitised mice. Based on the molecular structure, the present study also examined the structural modification of WGA in relation to the range of dose. Structural integrity was monitored using HPLC, fluorescence spectrometry and circular dichroism. Results showed a loss of intrinsic activity and the formation of insoluble amorphous aggregates with a lack of native conformational structures after irradiation. Current findings suggest that the allergenic epitopes of WGA became less active and antigenic after high-dose radiation. the reduction of cytokines typical of allergic reactions, with decreased lymphocytic infiltrate, was observed in the gut of mice given irradiated versus native WGA. Food irradiation proved effective and safe in combating immunological and allergic effects of WGA. (C) 2011 Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Ministerio da Ciencia e Tecnologia (Brazilian)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundacao de Amparo a Ciencia e Tecnologia do Estado de Pernambuco (FACEPE)Univ Fed Pernambuco, Dept Bioquim, Recife, PE, BrazilUniv Fed Pernambuco, Dept Histol & Embriol, Recife, PE, BrazilUniv Fed Pernambuco, Dept Biofis & Radiobiol, Recife, PE, BrazilUniv Fed Pernambuco, Dept Antibiot, Recife, PE, BrazilUniv Estadual Oeste Parana, Ctr Engn & Ciencias Exatas, Toledo, BrazilUniversidade Federal de São Paulo, Dept Bioquim, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Bioquim, São Paulo, BrazilWeb of Scienc

Xyloglucan and Concanavalin A based dressings in the topical treatment of mice wound healing process

For medical biomaterials, xyloglucan dispersions can form films or gels to be applied as a wound dressing. For this purpose, the structural characterization of xyloglucan dressing (XG) and xyloglucan dressing containing 0.5 mg/mL of concanavalin A (XGL) was performed. The lectin release capacity and stability, cytotoxicity, and pro-wound healing effects were also investigated. XG and XGL films were prepared by mixing 0.5 % (w/v) xyloglucan with 0.3 % (v/v) glycerol. The ConA incorporated in the xyloglucan dressing maintained its biological activity for fourteen days in a controlled-release manner. The films were non-toxic, homogeneous, flexible, and accelerated the wound contraction compared with the control group, promoting less infiltration of inflammatory cells, angiogenesis, remodeling, and early epithelization. The films also alleviate the inflammation phase by reducing the production of pro-inflammatory cytokines (IFN-, TNF-, IL-1, IL-6, and IL-12), especially the XGL film, which promoted the up- and down-regulation of important proteins associated with the wound repair. All these findings suggest that XG and XGL films may represent a good therapeutic approach for wound healing applications.The authors are grateful for the financial support for research grants from the Conselho Nacional de Desenvolvimento Científico e Tecnol ´ogico (CNPq), Coordenaç˜ao de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and the Fundaç˜ao de Amparo `a Ciˆencia e Tecnologia do Estado de Pernambuco (FACEPE). We are grateful to the Centro de Tecnologias Estrat´egicas do Nordeste (CETENE) and to the Laborat´orio de Imunopatologia Keizo Asami-LIKA at the Universidade Federal de Pernambuco (UFPE) for access to its installation and technical assistance.info:eu-repo/semantics/publishedVersio

Microbial DNA extraction methods for microbial screening - saliva vs biofilm comparison

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Optimized extraction of a lectin from Crataeva tapia bark using AOT in isooctane reversed micelles

Crataeva tapia bark lectin was extracted from a crude extract into a reversed micelle phase of the anionic surfactant AOT in isooctane and back-extracted, to a final aqueous phase by addition of butanol. The effects of pH, ionic strength and surfactant concentration on the protein transfer process from the aqueous to the organic phase were characterized, being the best results obtained after 5 min of contact, under agitation, between the two phases, at pH 5.5 (10 mM citrate-phosphate buffer), 30 mM NaCl, and 5 mM AOT. Recovery to a new aqueous phase was performed with 5 min of contact, under agitation, 10 mM citrate-phosphate buffer at pH 5.5, 500 mM KCl and 5% of butanol. The overall yield obtained for the process was 80% for lectin activity and 56% for protein recovery. The efficiency of the process was confirmed by SDS-PAGE analysis.ALFA/VALNATURA; CNPq

Prediabetes blunts DPP4 genetic control of postprandial glycaemia and insulin secretion

Funding Information: The PREVADIAB-2 study was supported by a grant from the Portuguese Directorate General of Health. This work was financed by Fundação para a Ciência e Tecnologia (reference number PTDC/BIM/MET/4265/2014), by iNOVA4Health UIDB/Multi/04462/2020 and by ONEIDA (project E-411021.01, Lisboa-01-0145-FEDER-016417, co-funded by FEEI [Fundos Europeus Estruturais e de Investimento] from Programa Operacional Regional Lisboa 2020. We also acknowledge the research infrastructure CONGENTO (project LISBOA-01-0145-FEDER-022170), co-financed by Lisboa Regional Operational Programme (Lisboa 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund and the Foundation for Science and Technology (Portugal).Aims/hypothesis: Imbalances in glucose metabolism are hallmarks of clinically silent prediabetes (defined as impaired fasting glucose and/or impaired glucose tolerance) representing dysmetabolism trajectories leading to type 2 diabetes. CD26/dipeptidyl peptidase 4 (DPP4) is a clinically proven molecular target of diabetes-controlling drugs but the DPP4 gene control of dysglycaemia is not proven. Methods: We dissected the genetic control of post-OGTT and insulin release responses by the DPP4 gene in a Portuguese population-based cohort of mainly European ancestry that comprised individuals with normoglycaemia and prediabetes, and in mouse experimental models of Dpp4 deficiency and hyperenergetic diet. Results: In individuals with normoglycaemia, DPP4 single-nucleotide variants governed glycaemic excursions (rs4664446, p=1.63x10−7) and C-peptide release responses (rs2300757, p=6.86x10−5) upon OGTT. Association with blood glucose levels was stronger at 30 min OGTT, but a higher association with the genetic control of insulin secretion was detected in later phases of the post-OGTT response, suggesting that the DPP4 gene directly senses glucose challenges. Accordingly, in mice fed a normal chow diet but not a high-fat diet, we found that, under OGTT, expression of Dpp4 is strongly downregulated at 30 min in the mouse liver. Strikingly, no genetic association was found in prediabetic individuals, indicating that post-OGTT control by DPP4 is abrogated in prediabetes. Furthermore, Dpp4 KO mice provided concordant evidence that Dpp4 modulates post-OGTT C-peptide release in normoglycaemic but not dysmetabolic states. Conclusions/interpretation: These results showed the DPP4 gene as a strong determinant of post-OGTT levels via glucose-sensing mechanisms that are abrogated in prediabetes. We propose that impairments in DPP4 control of post-OGTT insulin responses are part of molecular mechanisms underlying early metabolic disturbances associated with type 2 diabetes. Graphical abstract: [Figure not available: see fulltext.]publishersversionepub_ahead_of_prin

Sulfated small molecules targeting EBV in Burkitt lymphoma: from in silico screening to the evidence of in vitro effect on viral episomal DNA

Epstein–Barr virus (EBV) infects more than 90% of the world population. Following primary infection, Epstein– Barr virus persists in an asymptomatic latent state. Occasionally, it may switch to lytic infection. Latent EBV infection has been associated with several diseases, such as Burkitt lymphoma (BL). To date, there are no available drugs to target latent EBV, and the existing broad-spec trum antiviral drugs are mainly active against lytic viral infection. Thus, using computational molecular docking, a virtual screen of a library of small molecules, including xanthones and flavonoids (described with potential for antiviral activity against EBV), was carried out targeting EBV proteins. The more interesting molecules were selected for further computational analysis, and sub sequently, the compounds were tested in the Raji (BL) cell line, to evaluate their activity against latent EBV. This work identified three novel sulfated small molecules capable of decreasing EBV levels in a BL. Therefore, the in silico screening presents a good approach for the development of new anti-EBV agents.info:eu-repo/semantics/publishedVersio