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Kronenfrakturen, insbesondere im Rahmen von Frontzahntraumata, nehmen einen immer größeren Stellenwert bei der Behandlung von Kindern und Jugendlichen ein. Da auch in Zukunft mit einem weiteren Anstieg derartiger Verletzungen zu rechnen ist, muss an minimal-invasiven, ästhetischen und ökonomischen Therapiemöglichkeiten geforscht werden. Die Fragmentbefestigung mit Hilfe von Dentinadhäsiven mit oder ohne zusätzliche Verwendung von fließfähigem Komposit stellt derzeit die Methode der Wahl dar. Da es in den letzten Jahren zu einer Umstellung von Mehrflaschen-Adhäsiven auf Einflaschen-Adhäsive gekommen ist, sollten in der vorliegenden Arbeit Dentinadhäsivsysteme verschiedenen Generationen bezüglich ihres Bruchverhaltens nach Versagen der adhäsiven Befestigung getestet werden. Zudem sollte herausgefunden werden, ob unterschiedliche Frakturverläufe im Schmelz- und Dentinbereich zu beobachten sind. Humane extrahierte Zähne aus einer vorangegangenen Studie zur Bruchfestigkeit von Dentinadhäsiven dienten als In-vitro-Testsystem. Die Dentinadhäsive OptiBond FL®, Syntac®, AdheSE®, Adper® Prompt® L-Pop® sowie die kombinierte Anwendung von OptiBond FL® mit dem fließfähigen Komposit Tetric® Flow wurden anhand von lichtmikroskopischen Bruchflächenanalysen auf ihr Frakturverhalten nach Versagen der Fragmentbefestigung untersucht. Die Adhäsivsysteme untereinander unterschieden sich dabei bezüglich der Frakturverläufe kaum. Abweichungen gab es allerdings zwischen Schmelz- und Dentinbereich. Während es im Schmelzbereich zu einem ausgeglichenen Verhältnis von Kohäsiv- und Adhäsivfrakturen kam, dominierte im Dentinbereich der Anteil an Kohäsivfrakturen innerhalb des Restaurationsmaterials. Lediglich das Adhäsivsystem Syntac® fiel durch einen erhöhten Anteil an Adhäsivfrakturen im Dentinbereich und Adper® Prompt® L-Pop® durch einen hohen Prozentsatz an Adhäsivfrakturen im Schmelzbereich auf. In der Literatur werden Kohäsivfrakturen häufig mit hohen Haftwerten und Adhäsivfrakturen mit niedrigen Verbundfestigkeiten zwischen Zahn und Adhäsiv in Verbindung gebracht. Bei Adper® Prompt® L-Pop® konnte im Rahmen der vorangegangenen Studie eine verminderte Bruchfestigkeit gegenüber den anderen Adhäsivsystemen bestätigt werden. Zur Wiederbefestigung von Kronenfragmenten sind somit die modernen „Einflaschen-Adhäsivsysteme“ derzeit noch nicht zu empfehlen. Gefüllte Dentinadhäsive, wie OptiBond FL®, scheinen hingegen aufgrund ihrer höheren Bruchfestigkeit und ihrer langen klinischen Erfahrung für die Fragmentbefestigung geeignet zu sein. / Crown fractures are becoming more and more important in the dental treatment of children. The therapy of these tooth injuries has to fulfill the demands of a minimal invasive preparation, a pleasant aesthetic outcome as well as economical aspects. Currently, a standard treatment of crown fractures is the reattachment of the fragment with bonding agents. The aim of the present study was to investigate the fracture behaviour of different bonding agents following stress-induced failure of reattached crown fragments. Four kinds of failure modes should be analysed on the complementary interfaces of the crown fragment and tooth base (adhesive fractures to the crown fragment, adhesive fractures to the base, cohesive fractures inside the bonding agent and cohesive fractures inside the tooth material). Furthermore, differences between the failure mode of dentin and enamel ought to be analyzed. Extracted human teeth, which were already used within a previous study concerning the fracture strength of bonding agents, served as an in vitro experimental model. The bonding agents OptiBond FL®, Syntac®, AdheSE®, Adper® Prompt® L-Pop® as well as the combined application of OptiBond FL® with the flowable composite material Tetric® Flow were analyzed referring to the conditions of the fracture interface by optical microscopy. With the assistance of a special CAD-software the failure modes could be quantified. The analysis of the fracture behaviour revealed only scarce distinctions among the bonding agents. However, obvious differences between enamel and dentin areas could be observed. Within the enamel areas a balanced ratio of cohesive and adhesive fractures could be found, whereas the dentin areas presented predominantly cohesive fractures within the restoration material. Solely the bonding agent Syntac® showed a higher percentage of adhesive fractures within the dentin and the material Adper® Prompt® L-Pop® presented increased adhesive fractures within the enamel areas. As adhesive fractures, contrary to cohesive fractures, are often correlated to a minor bond strength between tooth substance and bonding agent, modern all-in-one bonding agents like Adper® Prompt® L-Pop® should currently not be recommended for the reattachment of crown fragments. Filled bonding agents like OptiBond FL® seem to be more advisable, based on their higher fracture strength and existing long-term clinical experience.

Um Arzneimittelwechselwirkungen von Arzneistoffen sowie neuen Arzneistoffkandidaten zu vermeiden, werden zur Abschätzung des Interaktionsrisikos so genannte In-vitro-Interaktionsstudien durchgeführt. Hierfür werden vor allem Mikrotiterplatten-basierte Fluoreszenz- und LC/MS-Methoden verwendet. Das Ziel dieser Arbeit war die Untersuchung der Anwendbarkeit und Validität dieser In-vitro-Methoden bezüglich der Inhibition von CYP-Enzymen durch Arzneipflanzenextrakte. Die in dieser Arbeit erhaltenen Daten belegen, dass die verwendeten Fluoreszenz-Assays für Pflanzenextrakte keine validen Ergebnisse liefern und für die Bestimmung der inhibitorischen Aktivität von Pflanzenextrakten nur in wenigen Fällen geeignet sind. Bei einigen untersuchten Pflanzenextrakten wurden sehr starke inhibitorische Aktivitäten gefunden, da durch Quenching des Fluoreszenzsignals falsch positive Ergebnisse vorgetäuscht wurden. Ebenso war die Inhibition bei einigen Pflanzenextrakten aufgrund einer starken Eigenfluoreszenz sehr schwach oder konnte überhaupt nicht bestimmt werden. Des Weiteren wurden als Referenzmethoden für die Bestimmung der Inhibition von CYP-Enzymen LC/MS-basierte Methoden mit Online-Festphasenextraktion verwendet, die speziell für Pflanzenextrakte entwickelt und validiert wurden. Die Ergebnisse der LC/MS-basierten CYP-Assays wurden durch die Pflanzenmatrix nicht beeinflusst, so dass diese Assays hervorragend als Referenzmethoden für die Bestimmung der inhibitorischen Aktivität von Pflanzenextrakten geeignet sind. Bei sehr hohen Extraktkonzentrationen zeigten einige Pflanzenextrakte sehr starke Abweichungen der mittels LC/MS und Fluorimetrie in Mikrotiterplatten erhaltenen inhibitorischen Aktivität. Die Verwendung von niedrigen Extraktkonzentrationen führte zu einer besseren Übereinstimmung der erhaltenen Ergebnisse. D.h. vor allem bei hohen Extraktkonzentrationen sind starke Quenching- und Eigenfluoreszenz-Effekte zu erwarten. Dennoch sind auch bei niedrigen Extraktkonzentrationen diese Effekte nicht auszuschließen. In den meisten Veröffentlichungen wurden sehr hohe Testkonzentrationen für die Bestimmung der inhibitorischen Aktivität von Pflanzenextrakten verwendet, so dass mit hoher Wahrscheinlichkeit aufgrund von Quenching- und Eigenfluoreszenz-Effekten falsch positive bzw. negative Ergebnisse erhalten wurden. Untersuchungen zum Quenching haben gezeigt, dass die meisten Extrakte in den üblicherweise verwendeten Konzentrationen (ca. 10-1000 µg/ml) die Fluoreszenzintensität der Metabolite sehr stark reduzierten. Die Quenching-Effekte der Pflanzenextrakte beeinflussten das Fluoreszenzsignal aller enzymatisch gebildeten Metabolite (Cumarin-Derivate, Resorufin, Fluorescein), wobei die Quenching-Effekte bei Resorufin und Fluorescein in ihrer Stärke und Häufigkeit geringer ausfielen. Bei CYP2B6, CYP2C9 und CYP2D6 wurden in Verbindung mit Fluoreszenzsubstraten, die eine Cumarinstruktur aufweisen, sehr oft falsch negative oder gar keine Ergebnisse erhalten, weil die Eigenfluoreszenz der Extrakte die Metabolitenfluoreszenz überlagerte. Quenching-Effekte traten bei den untersuchten Pflanzenextrakten weitaus häufiger auf als eine Eigenfluoreszenz. Aufgrund dieser Tatsachen können die Mikrotiterplatten-basierten Fluoreszenz-Methoden nur eingesetzt werden, wenn vorher gezeigt wurde, dass die Pflanzenextrakte bei allen Testkonzentrationen sowie bei verschiedenen Metabolitenkonzentrationen weder Quenching- noch Eigenfluoreszenz-Effekte zeigen. Ebenso wurde in dieser Arbeit gezeigt, dass die bisher in Veröffentlichungen durchgeführten Kontrollinkubationen nur bedingt zur Kompensation von Quenching- und Eigenfluoreszenz-Effekten geeignet sind. Das Auftreten und Ausmaß der Quenching- und Eigenfluoreszenz-Effekte sind abhängig vom Inhibitor (Pflanzenextrakt), der Inhibitorkonzentration, dem Metaboliten und dessen Anregungs- und Emissionswellenlänge sowie der Metabolitenkonzentration, die durch die enzymatische Umsetzung des Substrats und der inhibitorischen Aktivität des Inhibitors bestimmt wird. Während der Inhibitor, die zu testenden Inhibitorkonzentrationen, der Metabolit sowie dessen Anregungs- und Emissionswellenlänge eine feste Größe darstellen, ist die Metabolitenkonzentration je nach inhibitorischer Aktivität des Inhibitors sehr unterschiedlich. D. h. letztendlich hängt das genaue Ausmaß der Eigenfluoreszenz- und Quenching-Effekte von der inhibitorischen Aktivität der Pflanzenextrakte ab. Es konnte gezeigt werden, dass je geringer die Metabolitenkonzentration ist, desto stärker wird das Fluoreszenzsignal reduziert (Quenching) bzw. erhöht (Eigenfluoreszenz). Eine sinnvolle Kontrollinkubation zur Kompensation von Quenching- und Eigenfluoreszenz-Effekten kann also gar nicht durchgeführt werden. Bei In-vitro-Untersuchungen zur Bestimmung der inhibitorischen Aktivität ist die Metabolitenkonzentration nicht bekannt und somit der Einfluss der Effekte nicht bestimmbar. / To avoid interactions with drugs or new drug candidates, in vitro interaction studies are performed for the assessment of their drug interaction potential. For this purpose, microtiterplate-based fluorimetric and LC/MS-based methods are used. The goal of this work was to investigate the applicability and validity of the microtiterplate-based fluorescence methods with respect to the inhibition of CYP enzymes by plant extracts. The results show that the microtiterplate-based fluorimetric assays do not provide reliable results for plant extracts and that these assays are only suitable for the determination of the inhibitory activities of plant extracts in some cases. Several of the tested plant extracts showed very strong inhibitory activities. But, due to quenching effects, the extracts additionally reduced the fluorescence signals of the metabolites thereby pretending false positive results. Also, the inhibition of CYP enzymes by some plant extracts was very weak or even not determinable due to intrinsic fluorescence. Additionally, LC/MS-based methods with online solid phase extraction were developed and validated as reference methods for the determination of the inhibition of CYP enzymes. Since the results of the LC/MS-based assays were not affected by the matrix of the plant extracts, these assays are suitable reference methods for the determination of the inhibitory activities of plant extracts. At high extract concentrations some plant extracts showed strong deviations of the inhibitory activities using LC/MS- and microtiterplate-based fluorimetric assays. The use of low extract concentrations provided a good correlation of the obtained inhibitory activities. That means, especially high extract concentrations are responsible for strong quenching effects and intrinsic fluorescence thereby pretending false positive or negative results. Nevertheless, also at low extract concentrations these effects were observed. Interestingly, in most publications very high concentrations of plant extracts were used for the determination of the inhibitory activities, so that reduced or increased IC50 values were obtained due to quenching and intrinsic fluorescence. Analyses of the quenching effects showed that most extracts strongly reduced the fluorescence intensity of the metabolites at frequently used concentrations (ca. 10-1000 µg/ml). The quenching effects of the plant extracts decreased the fluorescence signal of all enzymatically produced metabolites (coumarin derivatives, resorufin and fluorescein), whereas the quenching effects for resorufin and fluorescein were much less potent and frequent. By using coumarin derivatives as substrates for CYP2B6, CYP2C9 und CYP2D6 often false negative or no results were obtained, because the intrinsic fluorescence of the extracts interfered with the metabolite fluorescence. Finally, quenching effects occurred more often than intrinsic fluorescence. Due to these facts, microtiterplate based fluorimetric methods are only useable if the plant extracts show neither quenching nor intrinsic fluorescence for all inhibitor concentrations at various metabolite concentrations. Also, analyses of this work showed that control incubations performed in recently published studies are only of limited use for the compensation of quenching effects and intrinsic fluorescence. The occurrence and the extent of quenching effects and intrinsic fluorescence depend on the inhibitor (plant extract), the inhibitor concentration, the metabolite and its excitation and emission wavelength as well as the metabolite concentration, which is determined by the inhibitory activity of the inhibitor. Whereas the inhibitor, the inhibitor concentration, the metabolite as well as its excitation and emission wavelength are constant parameters, the metabolite concentration depends on the inhibitory activity of the inhibitor. That means, the extent of quenching and intrinsic fluorescence depends mainly on the inhibitory activity of the plant extracts. Studies in this work showed that the lower the metabolite concentration the more the fluorescence signal is decreased (quenching) or increased (intrinsic fluorescence). Thus, control incubations to compensate quenching effects and intrinsic fluorescence are not valid, because the metabolite concentration is unknown and thus the influence of the effects is not determinable.

A maturação in vitro de oócitos (MIV) é uma importante tecnologia reprodutiva a qual gera oócitos maduros capazes de suportar o desenvolvimento embrionário pré-implantacional e sua completa evolução à termo. Muitos fatores levam ao processo de maturação do oócito, e o AMH (hormônio anti-Mülleriano) tem demonstrado possuir um importante efeito nesta etapa. Neste trabalho nós demonstramos a influência da suplementação de AMH na maturação de complexos cumulus-oócito (COCs). Nossos resultados demonstram que não houve efeito na produção de embriões para COCS grau I. Entretanto, pudemos encontrar diferenças significativas entre os COCs graus II e III maturados na presença de 150ng/ml de AMH. Aqui também demonstramos que não houve diferença significativa na expressão relativa de mRNA para os genes AMHRII e FSHR no oócito, e na expressão relativa de mRNA para os genes AMH, AMHRII e FSHR nas células da granulosa. Nossos resultados corroboram com as importantes funções do AMH na produção de embriões, sugerem que a suplementação do meio de maturação de oócitos com AMH pode ajudar a melhorar a produção de blastocistos. / The in vitro oocyte maturation (MIV) is an important reproductive technology that generates mature oocytes able to support the preimplantation embryonic development and their fully evolution to term. Many factors lead to oocyte maturation process, and the AMH (AntiMüllerian hormone) have demonstrated important effects in the oocyte development. Here, we report the influence of AMH supplementation in the cumulus-oocyte complex (COCs) maturation. We found that AMH had no effect on embryo production of COCs grade I. On the other hand, significant differences between the COCs grade II and COCs grade III matured in AMH 150ng/ml were verified. We have also demonstrated that there were no significant difference in mRNA expression of the genes AMHRII and FSHR in the oocyte, and in mRNA of the genes AMH, AMHRII and FSHR in the granulosa cells. Taken together, the results corroborate the important roles for AMH on embryo production, and suggest that AMH supplementation could achieve successful outcome in the production of blastocysts.

Submitted by Inácio de Oliveira Lima Neto (inacio.neto@inpa.gov.br) on 2017-12-12T12:49:24Z No. of bitstreams: 2 Josiane Celerino de Carvalho.pdf: 6852491 bytes, checksum: dcc1b722406d959e630215ab94d59860 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-12-12T12:49:24Z (GMT). No. of bitstreams: 2 Josiane Celerino de Carvalho.pdf: 6852491 bytes, checksum: dcc1b722406d959e630215ab94d59860 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-06-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Considering the advances of the studies with Hevea brasiliensis and the implementation of breeding programs, the propagation of this species has been recommended by the use of grafting. However, complete seed or parts there of (embryos) should not be neglected since, while maintaining the use of clones to improve production, genetics, biochemistry and functional characterization, in addition to the vigor and sanity of the propagated material may contribute to the complete formation of the plants by sexuada (seed germination) and asexual (embryo culture in vitro) for the selection of individuals more balanced in terms of rusticity and production. Thus, the objective of this work was to investigate the implications of the morphology and origin of the H. brasiliensis seeds on germination and seedling formation, from the morphological, histochemical, physiological and biochemical at view. The acquired seeds were categorized as coming from wild and clone matrices and were collected in Altamira-Pa and Belterra-Pa city’s, respectively. The seeds after asepsis were submitted to morphological, physiological and biochemical analyzes, beyond cultivation "in vitro". From the morphophysiological point of view, the seeds of wild and clone H. brasiliensis showed differences in size and color, being wild seeds larger and darker in color. There were no differences in germination morphology. Considering the viability of the seeds, they did not present differences in the moisture contents, and probably due to the high humidity the seeds showed proliferation of fungi, Aspergillus sp. and Penicillium sp., that cause deterioration in seeds. Regarding the germination physiology, the seeds showed a pattern of the three-phase model, but were different in relation to the soaking speed, and the wild seeds absorbed water more slowly than clone, but gain of fresh weight were no different between them. From the biochemical point of view, the constitution of the reserves were similar for both wild and clone seeds. Among the primary metabolites, the lipids correspond to the majority reserves stored in the endosperm of the seeds of the wild H. brasiliensis and clones individuals, being mobilized during germination and initial seedling growth. In the wild and clone seeds the proteins were also mobilized during germination and initial seedling growth and the soluble proteins were mobilized at the beginning of germination and exhibited protein bands in the bands of 7 to 30 kDa that may be associated with the main proteins of synthesis of the latex. Soluble sugar reserves were mobilized more intensely at the beginning of germination and starch at the beginning of seedling initial growth. In wild seeds and clone the nutrient phosphorus (P) and potassium (K) were mobilized at the beginning of germination and initial seedling growth, calcium (Ca) are mobilized at the beginning of germination, nitrogen (N) and magnesium (Mg) are mobilized in the initial growth of the seedlings. For micronutrients, the iron (Fe) was mobilized at the beginning of germination and initial growth of manganese (Mn) is poorly mobilized during germination and zinc (Zn) is mobilized at the beginning of initial seedling growth. The seeds and clone showed behavior and strategies mobilization of the primary metabolites and minerals during the germination and initial seedling growth. Morphological structures of the in vitro, hypocotyl, radicular (primary and secondary root) epicotyl and eophile present different sizes when compared to these same structures of seeds germinated in sand. The cultivation of zygotic embryos presented germination percentages closed to seeds germinated in sand, which may propagation of the species on a large scale. The disinfestation protocols were effective for the low contamination of the embryos. Highest mean of aerial part length was in culture medium with BAP growth and root part, with AIA growth regulator. The higher levels of protein in shoot and root observed in the culture media AIA and MS. The tissues of H. brasiliensis, aerial part and radicular showed protein bands in the bands from 7 to 30 kDa, which may be associated with the main proteins of the latex synthesis. Considering the results obtained in this work it is suggested that it is possible to produce healthy seedlings and perspectives to infer about the beginning of latex synthesis with a focus on future studies of these biomolecules. / Considerando os avanços dos estudos com Hevea brasiliensis e a implementação de programas de melhoramento, a propagação desta espécie tem sido recomendada pelo emprego da enxertia. Entretanto, os estudos com sementes completas ou partes delas (embriões) não devem ser negligenciados uma vez que, mantendo a utilização dos clones para aperfeiçoar a produção, pesquisas de caracterização genética, bioquímica e funcional, além do vigor e da sanidade do material propagado podem contribuir para verificar a formação completa das plantas por via sexuada (germinação das sementes) e assexuada (cultivo de embrião in vitro) visando a seleção de indivíduos mais equilibrados em termos de rusticidade e produção. Assim, o objetivo desse trabalho foi investigar as implicações da morfologia e origem das sementes de H. brasiliensis sobre a germinação e a formação das plântulas, do ponto de vista morfológico, histoquímico, fisiológico e bioquímico. As sementes utilizadas foram categorizadas como oriundas de matrizes selvagens e de clone e foram coletadas nos municípios de Altamira-Pa e Belterra-Pa, respectivamente. As sementes após assepsia foram submetidas às análises morfológicas, fisiológicas e bioquímicas, além do cultivo "in vitro". Do ponto de vista morfológico, as sementes de H. brasiliensis selvagens e de clone apresentaram diferenças quanto ao tamanho e coloração, sendo as sementes selvagens maiores e de coloração mais escuras. Quanto à morfologia da germinação, não apresentaram diferenças. Considerando a viabilidade das sementes, as mesmas não apresentaram diferenças nos teores de umidade, provavelmente, devido à alta umidade as sementes apresentaram proliferação de fungos, Aspergillus sp. e Penicillium sp., que causam deterioração em sementes. Em relação à fisiologia da germinação, as sementes apresentaram padrão trifásico, porém com diferenças em relação à velocidade de embebição, sendo que as sementes selvagens absorveram água de forma mais lenta do que o clone, quanto ao ganho de massa fresca das sementes não houve diferença. Do ponto de vista bioquímico, a constituição das reservas foi similar tanto para sementes selvagens, quanto para de clone. Dentre os metabólitos primários, os lipídeos, correspondem às reservas majoritárias estocadas no endosperma de sementes da espécie H. brasiliensis selvagem e clone e foram mobilizados durante a germinação e o crescimento inicial das plântulas. Nas sementes selvagens e clone as proteínas também foram mobilizadas durante a germinação e crescimento inicial de plântulas. As proteínas solúveis foram mobilizadas no início da germinação e exibiram bandas proteicas nas faixas de 7 a 30 kDa que podem estar associadas as principais proteínas de síntese do látex. As reservas de açúcares solúveis foram mobilizadas mais intensamente no início da germinação e o amido no início do crescimento inicial das plântulas. Nas sementes selvagens e clone os nutrientes fósforo (P) e o potássio (K) foram mobilizados no início da germinação e crescimento inicial de plântulas, cálcio (Ca) são mobilizados no início da germinação e, nitrogênio (N) e magnésio (Mg) durante o crescimento inicial das plântulas. Quanto aos micronutrientes, o ferro (Fe) foi mobilizado no início da germinação e crescimento inicial das plântulas, manganês (Mn) é pouco mobilizado durante a germinação e o zinco (Zn) é mobilizado no início do crescimento inicial das plântulas. As sementes selvagens e clone apresentaram comportamento e estratégias distintas de mobilização dos metabólitos primários e minerais durante a germinação e crescimento inicial das plântulas. As estruturas morfológicas das plântulas in vitro, hipocótilo, parte radicular (raiz primária e secundária), epicótilo e eofilos apresentam tamanhos diferentes quando comparadas a estas mesmas estruturas das sementes germinadas em areia. O cultivo de embriões zigóticos apresentaram porcentagens de germinação próximas às sementes germinadas em areia, fato que pode tornar vantajosa a propagação da espécie em larga escala. Os protocolos de desinfestação foram eficazes para a baixa contaminação dos embriões. Maior média de comprimento de parte aérea foi em meio de cultivo com reguladores de crescimento BAP e parte radicular, com regulador de crescimento AIA. Os maiores teores de proteínas na parte aérea e radicular foram observadas no meio de cultivo MS e com regulador AIA. Os tecidos de plântulas de H. brasiliensis, parte aérea e radicular exibiram bandas proteicas nas faixas de 7 a 30 kDa, que podem estar associadas as principais proteínas de síntese do látex. Considerando os resultados obtidos neste trabalho sugere-se que é possível se produzir plântulas saudáveis e com perspectivas de inferir sobre o início da síntese de látex com foco em futuros estudos destas biomoléculas.

Les microparticules à base de copolymères d’acides lactique et glycolique (PLGA) sont biocompatibles et biodégradables tout en permettant de contrôler la libération des principes actifs pendant quelques jours à plusieurs mois. Récemment, des stratégies ont été développées pour améliorer les propriétés de ces polymères en introduisant des groupements fonctionnels le long de la chaîne polymérique dans le but de moduler la libération des principes actifs.L’un des objectifs de ce travail a été d’étudier le potentiel de nouveaux copolymères fonctionnalisés portant des groupements carboxyliques pour la préparation de systèmes à libération contrôlée. L’apomorphine est encapsulée comme principe actif modèle. Son effet thérapeutique reste limité de part son court temps de demi-vie et son puissant effet émétique. Ainsi, des microparticules biodégradables, assurant une libération contrôlée de l’apomorphine, amélioreraient son efficacité thérapeutique et l’observance du traitement en réduisant la fréquence d’administration et les effets secondaires systémiques. Les microparticules chargées en apomorphine ont été préparées par une méthode d’émulsion à partir des nouveaux polymères fonctionnalisés, et de PLGA 50:50 de différentes masses moléculaires, pour comparaison. Les microparticules obtenues ont été caractérisées par différentes techniques. Le contenu résiduel en dichlorométhane (utilisé au cours de la formulation) a été quantifié et la libération de l’apomorphine a été étudiée in vitro. L’utilisation des polymères fonctionnalisés portant des fonctions carboxyliques libres a mené à une efficacité d’encapsulation plus élevée en apomorphine, de plus bas taux résiduels en dichlorométhane et à des cinétiques de libération in vitro de l’apomorphine distinctes de celles obtenues avec les PLGA traditionnels. Ces résultats suggèrent une application prometteuse de ces polymères fonctionnalisés pour la libération contrôlée de principes actifs. Une étape d’optimisation a ensuite consisté à modifier les paramètres de formulation afin d’étudier leur influence sur les caractéristiques des microparticules produites. L’objectif était notamment d’améliorer l’efficacité d’encapsulation tout en limitant la libération initiale d’apomorphine pouvant engendrer des pics de concentration néfastes, à l’origine d’effets indésirables. Ainsi, certains paramètres de formulation ont été modulés au cours de la préparation des microparticules à base de PLGA 50:50 de 10 kDa. La sélection de paramètres optimaux a mené au développement d’une formulation assurant une libération d’ordre zéro de l’apomorphine sur une période de dix jours.En outre, la littérature met en évidence l’importance des études de libération in vitro au cours du développement des microparticules de PLGA. Cependant, aucune méthode n’étant décrite par les autorités réglementaires, des conditions très différentes sont utilisées en pratique et leur influence sur les cinétiques de libération est peu connue. Par conséquent, une partie de ce travail a consisté à évaluer l’impact des conditions expérimentales sur les essais de libération in vitro à partir des microparticules. Différents systèmes couramment utilisés ont été employés pour les études de libération. Différents principes actifs modèles ont été encapsulés à différents taux de chargement et plusieurs techniques ont été utilisées pour caractériser les formulations obtenues. Des modèles mathématiques ont été appliqués pour mieux comprendre les phénomènes observés. Les résultats montrent que les conditions expérimentales peuvent influencer, de manière négligeable ou significative, les cinétiques de libération, en fonction du type de formulation et du système expérimental utilisé. Les différences observées peuvent être partiellement attribuées à des différences de mécanismes impliqués dans le processus de libération. Cet effet doit particulièrement être pris en considération avant de tirer toute conclusion à partir des études de libération in vitro. / Poly(lactic-co-glycolic) acid (PLGA)-based microparticles represent an attractive choice to sustain drug release over periods ranging from a few days up to several months, while ensuring good biocompatibility and complete biodegradability. Recently, tremendous efforts have been devoted to improve the properties of these copolymers by introducing functional groups along the polymeric chain, with the aim of modulating the drug release.On the one hand, the main objective of this work was to investigate the potential application of new functionalized copolymers bearing pendant carboxyl groups (PLA-co-PBED), as controlled drug delivery device. In this study, apomorphine was encapsulated as a model drug. Its therapeutic effect is limited due to its very short half-life and its strong emetic effect. Consequently, biodegradable microparticles would offer the advantage of improving therapeutic efficiency and compliance, by reducing administration frequency and minimizing systemic side effects. Apomorphine-loaded, PLA-co-PBED-based microparticles were prepared using an emulsion method. Microparticles based on PLGA 50:50 of different molecular weights were used as a reference. The obtained microparticles were characterized using various techniques. The residual content of dichloromethane (used as organic phase during microparticle preparation) was quantified and the in vitro release of apomorphine was studied. Interestingly, the functionalized polymers bearing free-carboxylic groups led to higher drug encapsulation efficiencies, lower residual contents of dichloromethane and different drug release patterns. These results suggest a promising application of these functionalized polymers to control drug release. Furthermore, the impact of the formulation parameters on the resulting physico-chemical properties of microparticles was studied. The main objective was to optimize the encapsulation efficiency, while minimizing initial burst release, to avoid toxic concentration peaks, and thus potential side effects. In this matter, some formulation parameters were varied during the preparation of microparticles based on PLGA 50:50 of 10 kDa. Optimal parameters were selected to achieve a zero-order apomorphine release over 10 days.On the other hand, it is well known that the in vitro drug release studies are crucial for the development of PLGA-based microparticles. However, as no standardized method has yet been established by authority agencies, very different methods are used in practice and their consequences on the resulting drug release kinetics are not well understood. Consequently, this work was intended to evaluate the impact of the experimental conditions on the resulting drug release kinetics from PLGA-based microparticles. Frequently applied setups were used. Different model drugs were encapsulated at different initial drug loadings. Various techniques were used to characterize the resulting formulations. Mathematical modeling was applied to better understand the observed phenomena. These results showed that the impact of the experimental conditions can be negligible or significant, depending on the type of formulation and the experimental setup. The observed differences could partially be explained by differences in the underlying drug release mechanisms. It can be concluded that great care must be taken when drawing conclusions from in vitro drug release measurements.

Syfte: Syftet med denna studie var att beskriva hur Lazarus och Folkmans copingstrategier används av kvinnor och män som genomgår IVF behandling, vid första försöket och vid försöken därefter. Metod: Studien har utförts som en kvalitativ metod med deskriptiv design, i form av frågeformulär där totalt sexton personer deltog. Tre män och tretton kvinnor. En innehållsanalys har utförts på det insamlade materialet vilket resulterade i att tre copingstrategier kunde identifieras. Huvudresultat: Resultatet visar att personer som genomgår IVF behandling använder sig av tre olika copingstrategier, en probleminriktad copingstrategi, en emotionellt inriktad copingstrategi samt en meningsbaserad copingstrategi. Hur dessa strategier används beror på individen och vart i behandlingsprocessen det gäller. Slutsats: Det visade sig att den grupp som hade gjort IVF förut hade mer erfarenhet inom området vilket innebar att deras huvudsakliga copingstrategi var behovet att prata med andra i liknande situationer, via bloggar eller forum. De som skulle göra IVF för första gången hade rädslor inför behandlingen och koncentrerade sig mer på det.