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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Antibody targeting of non ionic surfactant vesicles to vascular inflammation

Hood, Elizabeth D 01 June 2007 (has links)
Cardiovascular disease (CVD) and particularly atherosclerosis is a leading cause of morbidity in the developed world. Atherosclerosis and the rupture of vulnerable atherosclerotic plaque cause 70% of deaths from CVD. The progression of atherosclerosis has been identified as a pathological inflammatory process. Targeting atherosclerotic drug therapies to inflammatory markers has emerged as an important and growing research area. The adhesion molecule CD44 has been implicated in the onset and build-up of atherosclerotic lesions throughout the course of development. The research in this dissertation is aimed at targeting anti-inflammatory therapy to activated vascular endothelium with directed with an anti-CD44 antibody, IM7, conjugated to a non ionic surfactant vesicle (niosome) drug carrier. The IM7 conjugated immunoniosome has been shown to bind to endothelial and synovial lining cells in vitro. The preliminary research is involved with the development of the drug delivery vesicle, and the antibody linkage chemistry, along with an analysis of vesicle characteristics and stability. A novel linking chemistry using polyoxyethylene sorbitan monostearate and cyanuric chloride allows antibodies to be conjugated to vesicle surface polymer groups without prior derivatization. Subsequent research tested the resulting 'immunoniosome's' ability to bind to target antigens with selectivity and specificity. Bovine aortic endothelial cells activated with cytokines provide a model of inflammation. Analysis of binding was done through fluorescent and scanning electron microscopy. In vivo uptake of vesicles at sites of inflammation is size dependent. In order to overcome this barrier to uptake, niosome suspensions were thermally extruded to create uniform 200 nm vesicles. Further analysis of the efficacy of the system looked at live cell uptake of the immunoniosomes measured by confocal and transmission electron microscopy. Preparation for in vivo murine studies required that the antibody component was modified to counteract the immune response. Finally, the conjugation of antibody fragments to niosomes and the binding and uptake of the vesicles in a live endothelial cell model is evaluated. A viable drug delivery particle showing binding and cellular uptake capabilities in inflammatory cells was produced by this research using a novel surfactant-antibody linker.
2

Estudo da encapsulação da isotretinoína nas formas livre e associada a ciclodextrinas em niossomas / Research of isotretinoin encapsulation on its free form and associated to HP?Cyclodextrins in niosomes

Rodovalho, Luciana Ferreira Fonseca 15 December 2009 (has links)
Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2014-08-06T11:34:54Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Estudo_da_Encapsulacao_da_isotretinoina_nas_formas_livres_e_associada_a_ciclodextrinas_em_niossomas.pdf: 2030155 bytes, checksum: 19eecf0e1e4b0f42b01d0975d4634686 (MD5) / Made available in DSpace on 2014-08-06T11:34:54Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Estudo_da_Encapsulacao_da_isotretinoina_nas_formas_livres_e_associada_a_ciclodextrinas_em_niossomas.pdf: 2030155 bytes, checksum: 19eecf0e1e4b0f42b01d0975d4634686 (MD5) Previous issue date: 2009-12-15 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Fundação de Apoio à Pesquisa - FUNAPE / Non-ionic surfactant vesicles (niosomes) and cyclodextrins (CDs) are able to modify physical-chemical properties of incorporated drugs. One of the major challenges for the topical administration of retinoids, such as isotretinoin (31cisRA), is the stability of these compounds in formulations capable of reducing their toxicity during the treatment. The purpose of this research was to develop vesicular carries capable to transport and deliver isotretinoin for topical application during acne treatment. The niosomes were obtained from Bryj®30:Cholesterol:DCP (50:25:10) by the film hydration method. The HP CDs:isotretinoin complex was obtained by agitation for 8 days in phosphate buffer pH 7.4. The vesicles were characterized and it was possible to encounter a large amount of morphological varieties, flexible structures and fluid membrane, after inclusion of free isotretinoin. The fluidness of the membrane that contains isotretinoin allowed leaking of the drug when in concentration above 5 mM. The HP CDs:Isotretinoin (20:1) increased the vesicle size considerably, also allowing drug leaking. The systems developed presented themselves as potential carries of isotretinoin for topical application and played the roll of drug delivery system, / Os niossomas, vesículas formadas por tensoativos não-iônicos, e as ciclodextrinas (HP CDs) são sistemas capazes de alterar as características físico-químicas originais de diversos fármacos. O maior desafio da administração tópica de retinóides, como isotretinoína (ácido 13-cis-retinóico), é a manutenção de sua estabilidade em formulações capazes de reduzir a sua toxicidade durante o tratamento. A proposta deste trabalho foi desenvolver sistema para o transporte e liberação da isotretinoína com potencial para aplicação na terapêutica tópica da acne. Os niossomas foram formados a partir de Brij®30:Colesterol:DCP (50:25:10) pelo método de hidratação do filme lipídico. O complexo HP Ciclodextrinasisotretinoína foi obtido por agitação durante 8 dias em tampão fosfato pH 7,4. Os niossomas foram caracterizados sendo possível verificar grande variedade morfológica, estruturas flexíveis e membrana fluída após a inclusão da isotretinoína livre. A fluidez da membrana que contém isotretinoína permitiu o vazamento de fármaco quando em concentrações maiores que 5 mM. O complexo HP CDs:isotretinoína (20:1) aumentou consideravelmente o tamanho das vesículas, também permitindo vazamentos. Os sistemas desenvolvidos possuem potencial para uso como carreadores da isotretinoína na aplicação tópica demonstrando comportamento de “sistema de liberação modificado”.
3

The Preparation of theragnostic immunoliposomes/immunoniosomes and therapy of Parkinson's disease / La préparation de théragnostic immunoliposomes/immunoniosomes pour le diagnostic et thérapie de la maladie de Parkinson

Silindir Gunay, Mine 08 September 2016 (has links)
La maladie de Parkinson (MP) provient de la dégénérescence des cellules du locus nigerproduisant de la dopamine. La barrière hémato-encéphalique (BHE) est un véritable obstacle pour le traitement de la MP car elle empêche ou réduit le passage d’un grand nombre de substances pharmacologiques vers le cerveau. L’encapsulation de ces substances dans des liposomes ou des niosomes avant leur libération intra-cérébrale représente une alternative de choix en raison de la biocompatibilité, la biofragmentation, la non-toxicité et les capacités de ciblage de ces systèmes. A l’heure actuelle le traitement de la MP reste un défi, malgré l’existence de nombreux projets de recherche dans ce domaine. Notre hypothèse est que l’administration de pramipexoleencapsulé dans des liposomes et/ou des niosomes pourrait représenter une approche thérapeutique pertinente. Dans le cadre de la thèse, la caractérisation et la cinétique de diffusion des liposomes et niosomescontenant du pramipexole ont été réalisées. La validation de différentes formulations a été réalisée sur un modèle de BHE constitué de co-cultures cellulaires. Les effets du pramipexoleencapsulé dans des liposomes ou desniosomesont ensuite été étudiés dans un modèle de MP chez le rat obtenu par lésion de la voie dopaminergique nigro-striée à l’aide de 6-hydroxydopamine (6-OHDA). Pour cela, nous avons évalué le comportement rotatoire induit par l’amphétamine et l’expression du transporteur de la dopamine (DAT) par autoradiographie quantitative chez des animaux lésés traités ou non par les nanocapsules. Toutes les formulations que nous avons réalisées ont montré une capacité d’encapsulation d’environ 10% pour une taille de 100 nm, avec une cinétique de dispersion compatible avec une utilisation in vivo. Dans notre modèle de co-culture cellulaire, nous avons déterminé que nos formulations permettent le franchissement de la BHE. Chez les animaux lésés à la 6-OHDA, la quantification du DAT indique que l’administration de pramipexole réduit l’intensité de la lésion, que la substance soit administrée seule ou encapsulée dans des niosomes. Ces travaux montrent l’intérêt potentiel de l’administration de principe actif encapsulé pour le traitement de la MP, et devront être poursuivis afin d’optimiser cette approche thérapeutique, notamment au niveau des doses. / Parkinson’s Disease (PD) is degeneration of dopamine producing cells in substantia nigra. Blood-brain barrier (BBB) is a strong obstacle in PD therapy. More penetration and accumulation in the target tissue can be obtained by preventing RES uptake via “stealth effect”. Liposomes and niosomes are the promising systems for being biodegredable, bioavailable, non-toxic and targetable. Although CNS disorders are the first to endorse at their research in the diagnosis and therapy with several framework projects in Europe and over the world, there is still a huge gap in CNS drug delivery and the success of PD therapy. Although different studies have performed with pramipexole, evaluation of penetration and antiparkinsonian effect of pramipexole encapsulated liposomes and niosomes has never been studied before. Among this thesis, nanosized, polyethylene glycol (PEG) coated, neutral and positively charged, pramipexole encapsulated liposomes and noisomes were formulated, characterized and release kinetics of the systems were evaluated. In vitro penetration of all formulations was evaluated in BBB cell co-culture model. Therapeutic efficacy of neutral, pramipexole encapsulated liposomes and niosomes were evaluated in 6-hydroxydopamine (6-OHDA) lesioned rats by rotometer test and autoradiography. All formulations have approximately 10% encapsulation efficiency, around 100 nm particle sizes and fitted to first-order release kinetics. All formulations were found BBB permeable at in vitro cell culture studies. Nanosized, neutral niosomes designated similar but slightly better effect than pramipexole solution in autoradiograhy studies in 6-OHDA lesioned rats. This pramipexole dose is approximately 9 times lesser doses applied with conventional pramipexole tablets for humans in Neurology clinics. Nanosized, pramipexole encapsulated, neutral niosomes showed potential PD therapeutic effect in PD animal model depending on non-ionic surfactant properties of niosomes. / Uzm. Ecz. Mine Silindir Gunay, Parkinson Hastalığı’nın Teşhis ve Tedavisi İçin Kullanılacak Nanoboyutlu Teragnostik İmmünolipozom/İmmunoniozomlar Üzerine İn Vitro İn Vivo Çalışmalar, Hacettepe Üniversitesi – François Rabelais de Tours University, Sağlık Bilimleri Enstitüsü, Radyofarmasi Programı, UMR Inserm U 930, Ekip 3, Moleküler Görüntüleme ve Beyin Programı, Doktora Tezi, Ankara-Tours, 2016. Parkinson Hastalığı (PH) substantia nigra’daki dopamin üreten hücrelerin dejenerasyonundan kaynaklanmaktadır. Kan-beyin bariyeri (KBB) PH’nın tedavisinin önünde kuvvetli bir engeldir. Hedef dokudaki yüksek penetrasyon ve tutulum “stealth etki” ile RES tutulumunun engellenmesi ile sağlanabilir. Lipozom ve niozomlar biyoparçalanırlıkları, biyouyumlulukları, non-toksik ve hedeflendirilebilir olmaları nedeniyle en çok tercih edilen sistemlerdendir. Santral sinir sistemi hastalıklarının araştırılması Avrupa ve tüm dünyada yapılan pekçok çerçeve projelerinde ilk sırada olmasına rağmen, halen beyne ilaç taşınması ve PH’nin tedavi başarısı konusunda büyük boşluklar bulunmaktadır. Pramipeksol ile pek çok çalışma yapılmasına karşılık, bizim çalışmamız pramipeksol enkapsüle edilmiş lipozom ve niozomların beyin penetrasyonunun ve antiparkinson etkisinin değerlendirilmesi konusunda yenidir. Tez kapsamında, nanoboyutlu, PEG kaplı, nötral ve pozitif yüklü lipozom ve niozomların formüle edilmiş, karakterizasyon ve salım kinetikleri değerlendirilmiştir. Tüm formülasyonların KBB geçirgenliği, hücre KBB ko-kültürü çalışmalarında incelenmiştir. Nötral, pramipeksol enkapsüle edilen lipozom ve niozomların tedavi etkinliği in vivo olarak 6-hidroksidopamin (6-OHDA) ile lezyon yapılarak PH modeli oluşturulan sıçanlarda rotametre ve otoradyografi çalışmaları ile incelenmiştir. Tüm formülasyonlar yaklaşık %10 enkapsülasyon etkinliği ve 100 nm civarında partikül boyutu dağılımı ve birinci derece salım kinetiği göstermiştir. Hücre kültürü çalışmalarında, tüm formülasyonların KBB’nden penetre olabildiği saptamıştır. 6-OHDA lezyonlu sıçanlarda Parkinson hastalığının tedavisinde nanoboyutlu, nötral, pramipeksol enkapsüle edilen niozomlar, aynı dozdaki pramipeksol çözeltisi ile benzer hatta biraz daha iyi sonuçlar göstermiştir. Bu doz Nöroloji kliniklerinde Parkinson tedavisinde rutin olarak kullanılan konvansiyonel pramipeksol tabletlerindeki dozun yaklaşık olarak 9 kat düşük dozlarıdır. Nanoboyutlu, pramipeksol enkapsüle edilen, nötral niozomlar, niozomların non-iyonik sürfaktan özellikleri nedeniyle PH modeli sıçanlarda potansiyel bir antiparkinson terapötik etki göstermiştir.

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