Orientador: Silvio Roberto Andrietta / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-03T15:31:10Z (GMT). No. of bitstreams: 1 Vieira_ErikaDurao_M.pdf: 3130433 bytes, checksum: a9b8f1b36ccecb2daf18896dac4b39fa (MD5) Previous issue date: 2003 / Resumo: Este traballio teve como objetivo isolar e selecionar linhagens potencialmente produtoras de goma presentes na cana-de-açúcar. Gomas são biopolimeros de origem vegetal (e.g., gomas guar, carragena) ou microbiana (e.g., gomas xantana, dextrana). As linhagens produtoras de goma do tipo dextrana são freqüentemente encontradas em amostras de cana deteriorada. A dextrana é um biopolimero constituído de unidades monoméricas de a-Dglicose. A enzima dextrana-sacarase, responsável por sua síntese, é extracelular e tem a sacarose com principal indutor. Na indústria farmacêutica é que a dextrana tem a sua maior aplicabilidade: a dextrana de baixa massa molecular é utilizada como substituto do plasma sanguíneo e facilitador do fluxo sanguíneo. O microrganismo Leuconostoc mesenteroides NRRL B-512F, utilizado na maioria das indústrias produtoras de dextrana no mundo, serviu de referência para a seleção dos isolados. Para o isolamento, foram colhidas amostras de canade-açúcar deteriorada de 4 diferentes regiões e o caldo foi plaqueado em meio rico em sacarose, específico para produtores de goma. Colônias que apresentaram formação gomosa foram purificadas e estocadas em Litmus Milk a -15°C. Foram realizados ensaios em frascos agitados a 150 rprn, 28:tl°C por 12 horas para produção da enzima onde cada isolado foi incubado em meio contendo 5% de sacarose. A atividade enzimática do caldo centrifugado foi determinada medindo-se a velocidade de liberação de frutose. A goma foi produzida em meio contendo 15% de sacarose em frascos agitados a 150 rpm e 28:f:l°C por 15 horas. Etanol foi adicionado ao caldo bruto para precipitar a goma. As linhagens foram caracterizadas quanto à massa molecular média da dextrana produzida e à capacidade produtiva. A distribuição de massa molecular foi determinada por meio de cromatografia de permeação em gel (GPC). As análises de açúcares foram feitas em HPLC utilizando coluna de troca iônica com detecção por amperometria pulsada. Foram isolados cinqüenta e seis microrganismos e atividade enzimática foi evidenciada no caldo de vinte e oito linhagens. Destas, cinco foram selecionadas para produção e separação da goma. As atividades variaram de 33 a 131 UDS contra 49 UDS da linhagem referência nas condições do ensaio. Entre as cinco linhagens selecionadas, três são diplococos e produzem goma solúvel e duas são streptococos e produzem goma insolúvel. A análise de distribuição de massa molecular evidenciou que as linhagens selecionadas produzem goma de alta massa molecular, chegando a quase 2 milhões de Daltons / Abstract: The aim of this work was to isolate and select potentia1ly gum producing strains present in sugar cane. Guns are biopolymers carne 1Tom vegetal (e.g., guar gurn, carragen gum) or microbian (e.g., xantan gum, dextran gum) source. Dextran producing bacteria are 1Tequently found in damaged sugar cane. Dextran is a biopolymer that consists of a-Dglucose monomeric units. The enzyme dextransucrase, responsible for dextran synthesis, is extracellular and has sucrose as its main inductor. ln the pharmaceutical industry is where dextran has its larger applicability: low molecular weight dextran, clinical dextran, is used as blood-plasma substitute and blood flow improver. Leuconostoc mesenteroides NRRL B512F strain, used in the majority of dextran producing industries around the world, was used as reference for the isolated microorganisms selection. Damaged sugar cane sarnples, :ITom four di:fferent regions, were used as the microorganisms isolation source and the cane juice was inoculated in a 10% sucrose solid medium. Strains that had presented gummy colony formation were purmed and maintained in Litmus Milk broth at -15°C. Assays were conducted for enzime production in Erlenmyer flasks on a rotatory shaker at 150 rprn, 28::tl°C for 12 hours where each isolated microorganism was incubated in a 5% sucrose medium. The enzymatic activity of the centrifugated broth was determined by measuring :fi:uctose production rate. Gum was produced in Erlenmyer flasks containing of 15% sucrose medium on a rotatory shaker at 150 rprn, 28::tl°C for 15 hours. Etanol was added to the crude broth for gum precipitation. The strains were characterized by the produced dextran average molecular weight and by the productive capacity. The molecular weight distribution was determined by gel permeation chromatography (GPC). The sugar determination analyses were made by HPLC using an ion exchange column with amperiometric detention. Fifty six microorganisms were isolated and enzymatic activity was found in centrifugated broth of twenty eight strains. From these, tive had been selected for gum production. The activities varied 1Tom 33 to 131 UDS against 49 UDS :ITom the reference strain in the assay conditions. Among the tive selected strains, three are diplococci and produce soluble gum and the other two are streptococci and produce insoluble gum. The molecular weight distribution analysis showed that the selected strains produce high molecular weight gurn, one ofthem reaching almost 2 million Daltons / Mestrado / Desenvolvimento de Processos Biotecnologicos / Mestre em Engenharia Química

No description available.

A targeted, stimuli-responsive, polymeric drug delivery vehicle has been developed to help alleviate the severe side-effects caused by narrow therapeutic window drugs. Doxorubicin, a commonly used chemotherapeutic agent has been conjugated to dextran by two different techniques. In the first method, doxorubicin and hepatocyte-targeting galactosamine were attached to dextran through amine bonds. Conjugation efficiency based on the amount loaded of each reactant varied from 1% to 50% for doxorubicin and from 2% to 20% for galactosamine, depending on various synthesis parameters. For the second conjugate, doxorubicin was attached to dextran through an acid-labile hydrazide bond. Fluorescence quenching indicated that all our conjugates can bind to DNA. The degree of binding was improved with increasing polymer molecular weight and substitution of doxorubicin, and also with hydrazide-bonded conjugate. In cell culture experiments, we have found that the uptake of conjugates was much lower than that of free doxorubicin. Lower uptake of conjugates decreased the toxicity of doxorubicin. Also, the uptake of non-galactosylated conjugate was lower than that of the galactosylated conjugate. Microscopy studies indicated that doxorubicin was localized almost exclusively at the nucleus, whereas the amine-bonded conjugates were present throughout the cell. Targeted amine-linked conjugates and hydrazide-bonded conjugates achieved greatly improved cytotoxicity. Following uptake, the doxorubicin was dissociated from the hydrazide conjugate in an endosomal compartment and diffused to the nucleus. The LC₅₀ values of non-targeted amine-linked, targeted amine-linked, and hydrazide-linked doxorubicin were 19.81 μg/mL, 7.33 μg/mL and 4.39 μg/mL, respectively. The amine-linked conjugates were also tested on a multidrug-resistant cell line; the LC₅₀ values of doxorubicin and the non-targeted amine-linked conjugate were 8.60 μg/mL and 36.02 μg/mL, respectively. / Singapore-MIT Alliance (SMA)

L’objectif de ce travail est d’évaluer la biocompatibilité d’un copolymère de Dextrane- Polybutylmethacrylate utilisé comme revêtement de stent métallique en Cobalt-Chrome. L’étude s’est déroulée en trois phase : 1/La production du polymère et la caractérisation physico-chimique, 2/L’évaluation in vitro et 3/L’évaluation in vivo dans plusieurs modèles. Dans un premier temps deux copolymères de concentrations distinctes ont été synthétisés et mis en forme pour les différentes expériences. Leur caractérisation par FTIR, mesure d’angle de contact et une première implantation in vivo évaluant la réaction à corps étranger a permis d’ensélectionner un : le Dex-PBMA. Aucune réaction inflammatoire chronique n’a été observée. Desépreuves dynamiques et une observation des stents recouverts au MEB ont permis de confirmer la présence et la tenue du film de Dex-PBMA sur les stents. Des tests in vitro ont montré une faible d’adhésion bactérienne et plaquettaire ainsi qu’une thrombogénicité modérée. Un dispositif sous flux ex vivo et l’utilisation d’une molécule modèle - le Tacrolimus – ont montré la faisabilité d’utiliser le Dex-PBMA comme plateforme de libération de substances. In vitro, l’adhésion et la prolifération des progéniteurs endothéliaux ainsi que des cellules souches mésenchymateuses étaient faibles mais aucun effet toxique n’a été noté. Finalement les stents recouverts de Dex-PBMA ont été implantés in vivo dans un modèle d’aorte saine de rat puis dans un modèle de resténose chez le lapin. Chez le rat, après 30 jours, une hyperplasie limitée, l’absence de macrophage et une réendothélialisation des mailles ont été observées. Les premières implantations chez le lapin ont confirmé ces tendances mais l’étude doit être élargie afin d’en tirer une conclusion plus fiable. En conclusion, ces données démontrent que le Dex-PBMA est un matériau intéressant pour le revêtement de stent. / The purpose of this work was to study the biocompatibility of a dextran-graft-polybutylmethacrylate copolymer coated on cobalt chromium metallic stent. This study was divided in 3 parts: 1/the production of the copolymer and its physico-chemical characterization; 2/ its in vitro evaluation and 3/ its in vivo evaluation in several models. In the first step, 2 copolymers with different concentrations were synthetized and shaped for the following experiments. Their FTIR examination, contact angle measurement and a first in vivo implantation to evaluate foreign body reaction lead to the selection of one copolymer: the Dex-PBMA. No chronicle inflammatory reaction was noticed. Dynamic tests and SEM observations of coated stents confirmed the presence and the resistance of the Dex-PBMA coating. In vitro tests showed both low bacterial and platelet adhesions and a moderate thrombogenicity. An ex vivo test under flow with a model molecule – the Tacrolimus – showed the ability of Dex-PBMA to deliver drug. In vitro, the human endothelial progenitors and mesenchymal stem cells adhesion and proliferation were low but didn’t reveal any toxic effect. Finally Dex-PBMA coated stent were implanted in vivo in a healthy rat aorta model of stenting then in a rabbit model of restenosis. In rat, the intimal hyperplasia was moderate and an endothelium was present 30 days after stent implantation. First rabbit implantation confirmed these trends nevertheless this study must be extended to obtain significant results. In conclusion, these data demonstrate that Dex-PBMA is an interesting material for stent coating.

The distribution of neurons in the rostral nucleus of the solitary tract (rNST) that respond to gustatory input from the anterior tongue was visualized by Fos protein immunohistochemistry following electrical stimulation of the chorda tympani (CT) nerve in rats. Maps of Fos-immunoreactive (Fos-ir) neurons were compared with the distribution of CT afferent terminal fields labeled by transganglionic transport of rhodamine-dextran in a separate group of animals. The primary concentration of Fos-ir neurons localized in register with the major terminal fields of CT afferent fibers, in the central third of the rostral 1.0 mm of the NST ipsilateral to the stimulated nerve. A similar correspondence in location and degree of labeling of Fos-ir neurons and afferent terminals was observed in the ipsilateral dorsal spinal trigeminal complex (Sp5) pars caudalis, near the obex, and the Sp5 pars oralis near the rostral pole of the rNST. Thus, the magnitude of Fos upregulation in brainstem targets of the CT nerve having chemosensory or nociceptive function, was proportional to the relative density of the CT afferent input. This correspondence, and the absence of labeling in neurons known to be one additional synapse away from the afferent input within gustatory or oral reflex pathways, suggests that the cell map obtained represents mainly neurons that are directly activated via primary afferent synapses from CT fibers. The availability of a method to histochemically identify a population of putative second-order taste neurons will facilitate analysis of the cellular/molecular properties of these neurons and of synaptic circuitry in the rNST.

No description available.

As the two most abundant natural polymers on earth, cellulose and chitin have attracted increasing attention as a source of renewable energy and functional materials. Thin films of cellulose and chitin are useful for studying interactions of these materials with other natural and synthetic molecules via techniques such as quartz crystal microbalance with dissipation monitoring (QCM-D) and surface plasmon resonance (SPR). Because of the difficulty of extracting native cellulose, regenerated cellulose (RC), sulfated nanocrystalline cellulose (SNC), and desulfated nanocrystalline cellulose (DNC) thin films are often studied in its place. In this work, QCM-D solvent exchange studies showed that water contents of RC, SNC and DNC films were proportional to the film thickness (d). Accessibility and degradation of the films was further analyzed via substrate exposure to cellulase. Cellulase adsorption onto RC films was independent of d, whereas cellulase adsorption onto SNC and DNC films increased with d. Enhanced access to guest molecules for SNC and DNC films relative to RC films revealed they are more porous. The porosity of these cellulose films aided in understanding the observed differences of xyloglucan (XG) adsorption onto their surfaces. Xyloglucan adsorption onto RC, SNC, and DNC was studied by QCM-D and SPR. The amount of adsorbed XG increased in the order RC < SNC < DNC. XG adsorption onto RC films was independent of d, whereas XG adsorption was weakly dependent upon d for SNC films and strongly dependent upon d for DNC films. However, XG adsorbed onto "monolayer" thin films of RC, SNC, and DNC in approximately the same amount. These results suggested that the morphology and surface charge of the cellulose substrate had a limited effect upon XG adsorption and that accessible surface area of the cellulose film may be the factor leading to apparent differences in XG adsorption for different surfaces. The porosity and surface charge of SNC films presented a unique opportunity to examine polyelectrolyte adsorption and subsequent dewatering of the SNC substrate. The adsorption of a series of cationically derivatized dextran (cDex) polyelectrolytes with various degrees of substitution (DS) onto SNC was studied using QCM-D and SPR. As the hydrophobic character of the cDex samples increased, the water content of the adsorbed cDex layer decreased. For cDex with the greatest hydrophobic content, nearly 50% by mass of the initial water present in the porous SNC film was removed upon cDex adsorption. This study indicated that the water content of the film could be tailored by controlling the DS and hydrophobic character of the polyelectrolyte. This work also presents the first report of smooth, homogeneous, ultrathin chitin films, opening the door to surface studies of binding interactions, adsorption kinetics, and enzymatic degradation. The chitin films were formed by spincoating trimethylsilyl chitin onto gold or silica substrates, followed by regeneration to a chitin film. The utility of these chitin films as biosensors was evident from QCM-D and SPR studies that revealed bovine serum albumin adsorbed as a monolayer. / Ph. D.

Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-05-19T13:37:35Z No. of bitstreams: 1 luizgustavodeoliveira.pdf: 3109049 bytes, checksum: 4df3b04529f2b0980313cfda47b84ab7 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-19T14:46:00Z (GMT) No. of bitstreams: 1 luizgustavodeoliveira.pdf: 3109049 bytes, checksum: 4df3b04529f2b0980313cfda47b84ab7 (MD5) / Made available in DSpace on 2017-05-19T14:46:00Z (GMT). No. of bitstreams: 1 luizgustavodeoliveira.pdf: 3109049 bytes, checksum: 4df3b04529f2b0980313cfda47b84ab7 (MD5) Previous issue date: 2013-03-22 / Doenças inflamatórias intestinais, entre elas colite ulcerativa e doença de Crohn, compreendem um amplo espectro de afecções que apresentam em comum inflamação crônica do trato gastrointestinal. Colite ulcerativa afeta exclusivamente o cólon e o reto, possui etiologia ainda pouco conhecida podendo estar relacionada com fatores ambientais, genéticos e de resposta imune. O tratamento se baseia em medicamentos como aminossalicilatos, glicocorticóides e imunossupressores, porém seus efeitos colaterais atrapalham a adesão do paciente ao tratamento por longos períodos. Condroitim sulfato (CS) e glucosamina (GlcN) são atualmente indicados para o tratamento de doenças inflamatórias, como a osteoartrite, principalmente por apresentarem efeito anti-inflamatório ao diminuírem a ação do fator de transcrição NF-kB diminuindo a expressão de metaloproteases (MMP), TNF-α, iNOS entre outros mediadores inflamatórios. O objetivo deste trabalho foi analisar os efeitos da associação de CS e GlcN na colite ulcerativa experimental induzida por dextran sulfato de sódio (DSS) em ratos Wistar. Para isso foram avaliados o índice de atividade da doença (IAD), parâmetros hematológicos e bioquímicos, morfológicos e a atividade de MMP-2 e -9 da matriz extracelular no intestino grosso, concentração de NO tecidual e concentração de glicosaminoglicanos. Os animais foram divididos em quatro grupos: (1) controle, (2) controle + CS/GlcN, (3) DSS , (4) DSS + CS/GlcN. Observamos que o tratamento com CS/GlcN melhorou a severidade da colite aguda em ratos, verificado pela redução do score histológico e melhora de parâmetros hematológicos. CS/GlcN também reduziu a destruição de células caliciformes observados pelo azul de alcian, bem como a produção de óxido nítrico, a atividade de mieloperoxidase e metaloproteases, principalmente de MMP-9. Além disso, foi observado uma redução na concentração de GAGs total no grupo DSS + CS/GlcN quando comparado ao grupo DSS. Portanto, a administração de CS/GlcN apresentou melhoras em alguns dos parâmetros avaliados principalmente na atividade de MMP-9, mostrando um potencial destes compostos para futura utilização no tratamento dessa patologia. / Inflammatory bowel disease, including ulcerative colitis and Crohn's disease comprising a broad spectrum of diseases those have in common chronic inflammation of the gastrointestinal tract. Ulcerative colitis affects only the colon and rectum, has still poorly understood etiology and this could may be related to environmental factors, genetic and immune response. Treatment is based on drugs as aminosalicylates, immunosuppressants and glucocorticoids, but its side effects hinder patient compliance with treatment for long periods. Chondroitin sulphate (CS) and glucosamine (GlcN) are currently indicated for treatment of inflammatory diseases such as osteoarthritis, mainly because of the anti-inflammatory effect by decreasing the activity of transcription factor NF-kB and decreasing the expression of metalloproteases (MMP), TNF-α, iNOS and other inflammatory mediators. The objective of this study was to analyze the effects of the combination of CS and GlcN in experimental ulcerative colitis model induced by dextran sulfate sodium (DSS) in rats. To do so we evaluated the disease activity index (DAI), haematological and biochemical parameters, morphological changes and activity of MMP-2 and -9, NO and glycosaminoglycans concentration in the large intestine. Animals were divided into four groups: (1) control, (2) control + CS / GlcN, (3) DSS-induced colitis, (4) DSS + CS / GlcN. We observed that treatment with CS/GlcN improved the severity of acute colitis in rats verified by histological score reduction and improvement in hematological parameters. CS/GlcN also reduced goblet cells destruction observed by alcian blue, as well as nitric oxide production, the activity of myeloperoxidase and metalloproteases, especially MMP-9. Moreover, we observed a reduction in the concentration of total GAG + DSS group CS / GlcN when compared to DSS. Therefore, administration of CS/GlcN showed improvements in some of the parameters evaluated mainly on the activity of MMP-9, showing a potential future use of these compounds for the treatment of this pathology.

La consommation de polyphénols, micronutriments largement répandus dans lesaliments d’origine végétale, a été associée à la diminution du risque de développement denombreuses pathologies telles que maladies cardiovasculaires, maladies neurodégénérativesou cancers. Cet effet des polyphénols s’explique en partie par leurs propriétés antioxydanteset anti-inflammatoires. Du fait de leur faible absorption au niveau de l’intestin grêle, lespolyphénols sont présents en grande quantité dans le côlon où ils peuvent exercer cespropriétés. L’inflammation intestinale fait interagir le système immunitaire intestinal avecde nombreux facteurs environnementaux et est fréquemment associée à une augmentationdu stress oxydant via la production d’espèces réactives de l’oxygène par les cellulesimmunitaires. De nombreuses études ont montré, sur des modèles animaux d’inflammationintestinale, les effets protecteurs de certains polyphénols. La verveine odorante (Aloysiatriphylla (L’Hérit.) Britton) est une plante médicinale connue pour ses vertus thérapeutiquesdigestives et anti-spasmodiques et couramment consommée en infusion. L’infusé deverveine odorante contient de grandes quantités de polyphénols (acides phénoliquescomplexes et dérivés de flavones) et ses propriétés antioxydantes ont été mises en évidenceaussi bien in vitro qu’in vivo.L’objectif de cette thèse a donc été d'évaluer l’effet d’une consommation préventived’un infusé de verveine odorante à dose nutritionnelle (40 g/l et 4 g/l) sur le développementd’une inflammation intestinale modérée chez le rat. Des rats Wistar ont consommé commeboisson l’infusé de verveine seul pendant deux semaines puis associé à un agentinflammatoire, le sulfate de dextran sodique (DSS), à 4% pendant 7 ou 9 jours. L’effet de laverveine a été évalué sur différents paramètres cliniques (diarrhée, saignements rectaux,poids corporel), marqueurs de l’inflammation (longueur du côlon, score histologique,activité myéloperoxydase, cytokines) et du stress oxydant (peroxydation lipidique,glutathion, défenses antioxydantes enzymatiques). Les cellules immunitaires ont étéidentifiées dans le sang ainsi que dans les structures lymphoïdes secondaires par cytométrieen flux. Enfin l’étude du métabolisme des polyphénols en situation inflammatoire ou non aété initiée par l’analyse de l’excrétion urinaire des dérivés polyphénoliques.Lors d’une inflammation de 7 jours, la consommation préventive d’infusé deverveine à 40 g/l et 4 g/l retarde l’apparition de diarrhée et de saignements rectaux, limite larétraction du côlon et la diminution de la prise de poids des rats. Malgré l’absence d’effetsur l’activité myéloperoxydase, l’infusé à 40 g/l atténue les altérations histologiques de lamuqueuse colique induites par l’inflammation. L’infusé à 4 g/l stimule l’activité de lasuperoxyde dismutase et réduit la peroxydation lipidique. Les deux infusés modulent lespopulations de cellules immunitaires dans les structures lymphoïdes secondaires (ganglionsmésentériques et plaques de Peyer), en particulier les lymphocytes B et les lymphocytes Tcytotoxiques. L’excrétion urinaire des polyphénols de la verveine est faible et n'est pasaffectée par l'inflammation. Lors d’une inflammation de 9 jours, les deux infusés limitentl’augmentation d’activité de la myéloperoxydase. Seul l’infusé à 40 g/l limite la rétractiondu côlon, stimule l’activité de la glutathion réductase et diminue les taux d’IL-6 et deTNF-α. Ainsi, nous avons montré qu’une consommation préventive d’un infusé de verveineodorante offre des effets protecteurs lors de l’inflammation intestinale en agissant àdifférents niveaux. L’exploration des voies de signalisation impliquées pourrait permettre demieux comprendre les effets protecteurs de cette boisson de consommation courante. / Polyphenols are micronutrients widely distributed in foods of plant origin and theirconsumption has been associated with a decreased risk of various pathologies such ascardiovascular diseases, neurodegenerative diseases and cancer. This effect of polyphenolsis sustained by their antioxidative and anti-inflammatory properties. Due to their poorabsorption in the small intestine, high amounts of polyphenols reach the colon where theycan exert such properties. Intestinal inflammation results from an interaction between gutimmunity and various environmental factors and is frequently associated with an increase ofoxidative stress. Numerous studies have shown protective effects of polyphenols in animalcolitis models. Lemon verbena (Aloysia triphylla (L’Hérit.) Britton) is a medicinal herbknown for its digestive and antispasmodic properties and is widely consumed as an infusion.Lemon verbena infusion contains large amounts of polyphenols (complex phenolic acidsand flavone glycosides) and their antioxidative properties have been shown in vitro and invivo.The aim of the present thesis was to evaluate the effects of a preventive consumptionof lemon verbena infusion at nutritional doses (40 g/l and 4 g/l) on the development of amoderate colitis in the rat. Wistar rats ingested lemon verbena infusion alone as a drink fortwo weeks and then associated with the inflammatory agent dextran sulfate sodium (DSS) at4% for 7 or 9 days. Effects of lemon verbena were evaluated on several clinical parameters(diarrhoea, rectal bleeding, body weight), inflammatory markers (colon length, histologicalscore, myeloperoxidase activity, cytokines) and oxidative stress markers (lipid peroxidation,glutathione, antioxidative enzymatic defenses). Immune cells were identified in blood andgut associated lymphoid structures using flow cytometry. Moreover, the study of polyphenolmetabolism was initiated by the analysis of urinary polyphenol metabolites in healthy andcolitis rats.During a 7 days inflammation, the preventive consumption of lemon verbenainfusion at 40 g/l and 4 g/l delays apparition of diarrhoea and rectal bleeding, limits thecolon length reduction and the decrease of body weight gain. Despite no effect onmyeloperoxidase activity, the 40 g/l infusion attenuates colonic mucosa alterations due tothe colitis. The 4 g/l infusion increases superoxide dismutase activity and reduces lipidperoxidation. Both infusions modulate immune cell populations in gut associated lymphoidstructures (mesenteric lymph nodes and Peyer patches), especially B cells and cytotoxic Tcells. Urinary excretion of lemon verbena polyphenols is low and not modified byinflammation. During a 9 days inflammation, both lemon verbena infusions limitmyeloperoxidase increase. Only the 40 g/l infusion reduces colon retraction, increasesglutathione reductase activity and reduces colonic IL-6 and TNF-α levels.Thus, we have shown that the preventive consumption of a lemon verbena infusionprovided protection against intestinal inflammation at different levels. Exploration ofvarious signalling pathways could allow better insight into the protective effects of thiscommon beverage.

Active Pharmaceutical Ingredients with poor solubility have presented significant difficulties in drug product design and development including slow and ineffective absorption leading to inadequate and variable bioavailability. Therefore it has become increasingly desirable to overcome the low aqueous solubility of drug candidates and develop more novel and innovative formulation approaches to increase the dissolution rate of the poorly soluble drugs. This work focuses on the formulation of novel amorphous ibuprofen-polymer nanoconjugates based on the polymer-drug complexation in order to improve its physical and dissolution characteristics without the use of toxic organic solvents. Plain and ibuprofen-loaded binary and ternary nanoconjugates were prepared using four modified co-precipitation techniques including melt solubilization; alkaline solubilization; surfactant solubilization and hydrotropic complexation techniques. A remarkably high loading capacity was achieved ranging from 89.05 to 99.49% across the four techniques and polymer-polymer ratio of 50:50 was found to be most efficient. All the four techniques reduced the size of ibuprofen (2.87 μm) significantly in the presence of 2.0 x10-3 mM of Diethylaminoethyl Dextran (DEAE-Dextran) in the order melt solubilization (203.25 nm) > alkaline solubilization (185.68 nm) > surfactant (Tween 80) solubilization (122.17 nm) > hydrotropic complexation (77.92 nm). 5.0 x 10-4 mM of chitosan also reduced the size of ibuprofen from 2872.12 to 10.70 nm (268-fold reduction). The FTIR spectroscopic analysis revealed electrostatic, hydrophobic and hydrogen bonding interaction between solubilized ibuprofen and the cationic polymers (DEAE-Dextran and chitosan) to form a new product (an amide). Polymer-polymer complexation also occurred between DEAE-Dextran and gellan as well as chitosan and gellan to a different extent depending on the mixing ratios. 1H and 13C NMR analysis confirmed the conjugation between ibuprofen and each of the cationic polymers as well as the formation of a new amide product. DSC thermal analysis showed that the nanoconjugates exhibited new broad and diffuse peaks confirming that they did exist in amorphous state as multiple complexes. The TGA thermograms of the binary nanoconjugates exhibited one step degradation profile compared with the physical mixture which exhibited two steps. However the ternary nanoconjugates exhibited two steps degradation profile confirming the formation of multiple complexes. Marked enhancement of drug release was achieved by the four techniques compared with the ibuprofen control. All the DG (DEAE-Dextran - Gellan) complexes exhibited a higher release profile than ibuprofen control. Fickian and non-Fickian anomalous mechanisms were deduced for the drug release of ibuprofen from the binary conjugates. The ternary nanoconjugates exhibited non-Fickian (anomalous) diffusion, Fickian diffusion and Super Case II transport release mechanisms. The ternary nanoconjugate hydrogels exhibited complete release (100%) within 48 h. The lowest concentration of DEAE-Dextran, Gellan - Ibuprofen - DEAE-Dextran (GIbDD) 2:0.125, increased the release of ibuprofen by 13.4% however higher concentrations of DEAE-Dextran decreased the release profile steadily. It was concluded that DEAE-Dextran has potentials in the formulation of modified (extended) release of ibuprofen. The most prominent mechanism of release of ibuprofen from the nanoconjugate hydrogel was Super Case II transport. SEM and AFM micrographs of the drug loaded composite pharmaceutical films exhibited concentric spheres with two and three layers for the binary and ternary films respectively. This supports the evidence of internalization of ibuprofen by the polyelectrolyte complex. The FTIR and DSC results confirmed electrostatic and hydrophobic interactions between ibuprofen and DEAE-Dextran as well as between gellan and DEAE-Dextran. Thermal analysis revealed that plain bilayer films were thermally more stable than composite films. The addition of ibuprofen significantly increased (p < 0.05, n = 4) the swelling ratio of the films compared with films without the drug. The drug loaded bilayer films exhibited Fickian diffusion mechanism while the dominating mechanism for composite films was anomalous (Non-Fickian) transport. From the foregoing, it was evident that ibuprofen-polymer nanoconjugate present a novel tool for the delivery of ibuprofen with potential application for transdermal delivery.