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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.
171

Barcoded DNA Sequencing for Parallel Protein Detection

Dezfouli, Mahya January 2015 (has links)
The work presented in this thesis describes methodologies developed for integration and accurate interpretation of barcoded DNA, to empower large-scale-omics analysis. The objectives mainly aim at enabling multiplexed proteomic measurements in high-throughput format through DNA barcoding and massive parallel sequencing. The thesis is based on four scientific papers that focus on three main criteria; (i) to prepare reagents for large-scale affinity-proteomics, (ii) to present technical advances in barcoding systems for parallel protein detection, and (iii) address challenges in complex sequencing data analysis. In the first part, bio-conjugation of antibodies is assessed at significantly downscaled reagent quantities. This allows for selection of affinity binders without restrictions to accessibility in large amounts and purity from amine-containing buffers or stabilizer materials (Paper I). This is followed by DNA barcoding of antibodies using minimal reagent quantities. The procedure additionally enables efficient purification of barcoded antibodies from free remaining DNA residues to improve sensitivity and accuracy of the subsequent measurements (Paper II). By utilizing a solid-phase approach on magnetic beads, a high-throughput set-up is ready to be facilitated by automation. Subsequently, the applicability of prepared bio-conjugates for parallel protein detection is demonstrated in different types of standard immunoassays (Papers I and II). As the second part, the method immuno-sequencing (I-Seq) is presented for DNAmediated protein detection using barcoded antibodies. I-Seq achieved the detection of clinically relevant proteins in human blood plasma by parallel DNA readout (Paper II). The methodology is further developed to track antibody-antigen interaction events on suspension bead arrays, while being encapsulated in barcoded emulsion droplets (Paper III). The method, denoted compartmentalized immuno-sequencing (cI-Seq), is potent to perform specific detections with paired antibodies and can provide information on details of joint recognition events. Recent progress in technical developments of DNA sequencing has increased the interest in large-scale studies to analyze higher number of samples in parallel. The third part of this thesis focuses on addressing challenges of large-scale sequencing analysis. Decoding of a huge DNA-barcoded data is presented, aiming at phase-defined sequence investigation of canine MHC loci in over 3000 samples (Paper IV). The analysis revealed new single nucleotide variations and a notable number of novel haplotypes for the 2nd exon of DLA DRB1. Taken together, this thesis demonstrates emerging applications of barcoded sequencing in protein and DNA detection. Improvements through the barcoding systems for assay parallelization, de-convolution of antigen-antibody interactions, sequence variant analysis, as well as large-scale data interpretation would aid biomedical studies to achieve a deeper understanding of biological processes. The future perspectives of the developed methodologies may therefore stem for advancing large-scale omics investigations, particularly in the promising field of DNA-mediated proteomics, for highly multiplex studies of numerous samples at a notably improved molecular resolution. / <p>QC 20150203</p>
172

Microfluidic-Based In-Situ Functionalization for Detection of Proteins in Heterogeneous Immunoassays

Asiaei, Sasan January 2013 (has links)
One the most daunting technical challenges in the realization of biosensors is functionalizing transducing surfaces for the detection of biomolecules. Functionalization is defined as the formation of a bio-compatible interface on the transducing surfaces of bio-chemical sensors for immobilizing and subsequent sensing of biomolecules. The kinetics of functionalization reactions is a particularly important issue, since conventional functionalization protocols are associated with lengthy process times, from hours to days. The objective of this thesis is the improvement of the functionalization protocols and their kinetics for biosensing applications. This objective is realized via modeling and experimental verification of novel functionalization techniques in microfluidic environments. The improved functionalization protocols using microfluidic environments enable in-situ functionalization, which reduces the processing times and the amount of reagents consumed, compared to conventional methods. The functionalization is performed using self-assembled monolayers (SAMs) of thiols. The thiols are organic compounds with a sulphur group that assists in the chemisorption of the thiol to the surface of metals like gold. The two reactions in the functionalization process examined in this thesis are the SAM formation and the SAM/probe molecule conjugation. SAM/probe molecule conjugation is the chemical treatment of the SAM followed by the binding of the probe molecule to the SAM. In general, the probe molecule is selective in binding with a given biomolecule, called the target molecule. Within this thesis, the probe molecule is an antibody and the target molecule is an antigen. The kinetics of the reaction between the probe (antibody) and the target biomolecule (antigen) is also studied. The reaction between an antigen and its antibody is called the immunoreaction. The biosensing technique that utilizes the immunoreaction is immunoassay. A numerical model is constructed using the finite element method (FEM), and is used to study the kinetics of the functionalization reactions. The aim of the kinetic studies is to achieve both minimal process times and reagents consumption. The impact of several important parameters on the kinetics of the reactions is investigated, and the trends observed are explained using kinetic descriptive dimensionless numbers, such as the Damköhler number and the Peclet number. Careful numerical modeling of the reactions contributes to a number of findings. A considerably faster than conventional SAM formation protocol is predicted. This fast-SAM protocol is capable of reducing the process times from the conventional 24-hours to 15 minutes. The numerical simulations also predict that conventional conjugation protocols result in the overexposure of the SAM and the probe molecule to the conjugation reagents. This overexposure consequently lowers conjugation efficiencies. The immunoreaction kinetics of a 70 kilo-Dalton heat shock protein (HSP70) with its antibody in a hypothetical microchannel is also investigated through the FEM simulations. Optimal reaction conditions are determined, including the flow velocity and the surface concentration of the immobilized probes (antibodies). Based on the numerical results and a series of experimental studies, the fast-SAM protocol application is successfully confirmed. Moreover, the optimum reagent concentration for a given one- hour conjugation process time is determined. This functionalization protocol is successfully applied to immobilize the HSP70 antibody on gold surfaces. The use of the fast-SAM protocol and the predicted optimum conjugation conditions result in binding of the HSP70 antibody on gold, with the same or superior immobilization quality, compared to the conventional protocols. Upon implementation of a 70 μm.s^(-1) flow velocity, the reaction is observed to complete in around 30-35 minutes, which is close to the numerically predicted 30 minutes and 16 seconds. This immunoreaction time is considerably less than conventional 4-12 hour processes. The modified in-situ functionalization techniques achieved here are promising for substantially reducing the preparation times and improving the performance of biosensors, in general, and immunoassays, in particular.
173

Aspectos clássicos e quânticos de espinores de dinânima não-usual: espinores de dimenssão de massa um / Classical and quantum aspects of non-usual dynamic spinors: mass-dimension-one spinors

Rogério, Rodolfo José Bueno [UNESP] 14 September 2018 (has links)
Submitted by Rodolfo José Bueno Rogério (rodolforogerio@gmail.com) on 2018-11-12T17:40:08Z No. of bitstreams: 1 Tese.pdf: 1544164 bytes, checksum: 89834185eb568c41263eb552802f9252 (MD5) / Approved for entry into archive by Pamella Benevides Gonçalves null (pamella@feg.unesp.br) on 2018-11-14T13:18:34Z (GMT) No. of bitstreams: 1 rogerio_rjb_dr_guara.pdf: 1544164 bytes, checksum: 89834185eb568c41263eb552802f9252 (MD5) / Made available in DSpace on 2018-11-14T13:18:34Z (GMT). No. of bitstreams: 1 rogerio_rjb_dr_guara.pdf: 1544164 bytes, checksum: 89834185eb568c41263eb552802f9252 (MD5) Previous issue date: 2018-09-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Na presente tese apresentaremos de forma detalhada o estudo sistemático de uma teoria quântica com férmions de dimensão de massa um que obedecem as estatísticas de Fermi-Dirac, abordando essencialmente sua construção, quantização do campo, análise dos observáveis físicos e aplicações quânticas. Forneceremos todos os detalhes de uma descoberta teórica inesperada da partícula de spin $1/2$ que compõe um conjunto completo de autoespinores com helicidade dual do operador conjugação de carga. Esses espinores recebem o nome de Elko, um acrônimo proveniente do Alemão \textit{Eigenspinoren des Ladungskonjugationsoperators}. Veremos que o elo entre os espaços de representação $(1/2, 0)$ e $(0, 1/2)$ não é dado pela simetria de paridade mas sim pela ``Mágica das matrizes de Pauli'', e, portanto, como consequência a dinâmica de tais campos será regida única e exclusivamente pela dinâmica de Klein-Gordon. Tal fato faz com que o propagador associado ao Elko guarde muita similaridade com o propagador do campo escalar. Intrinsicamente, em sua formulação embrionária, as somas de spin para o Elko mostram um termo que quebra explicitamente a covariância relativística, levando então à apreciação da \textit{Very Special Relativity}, que nada mais é do que um subgrupo do grupo de Lorentz, cuja álgebra deixa as somas de spin invariantes ou covariantes. Entretanto, mostraremos que existe uma liberdade na definição da estrutura dual, a qual permite que seja construída uma teoria local e invariante por transformações de Lorentz, levando, assim, a uma nova física bastante interessante e promissora. / The present thesis covers in details a systematic study of a quantum theory based on mass dimension one fermions which satisfy the Fermi-Dirac statistics, essentially addressing its construction, field quantization, analysis of physical observables and quantum applications. We provide all the details of an unexpected theoretical discovery of a spin 1/2 particle which composes a complete set of dual helicity spinors of the charge conjugation operator. Such spinors are called Elko, an acronym for the German word Eigenspinoren des Ladungskonjugationsoperators. We show that the relation between the representation spaces (1/2,0) and (0,1/2) is given by the “Magic of Pauli matrices” rather than parity symmetry, therefore, as a consequence the dynamic of such fields is governed solely and exclusively by the Klein-Gordon dynamic. Such fact makes the Elko propagator to be very similar to the scalar field propagator Intrinsically, in its embryonic formulation, Elko spin sums shows up a term that explicitly breaks relativistic covariance, leading to the appreciation of Very Special Relativity, a theory which is based on a subgroup of the Lorentz group, whose algebra leaves the spin sums invariant or covariant. However, we show a freedom in the dual structure definition, which allows the construction of a local and Lorentz invariant theory, thus, leading to a very interesting and promising new physics
174

Avaliação imunológica de vacina de polissacarídeo meningocócico C conjugado e encapsulado em lipossomo / Immunological evaluation of meningococcal polysaccharide C conjugate vaccine and encapsulated liposome

Glauber da Costa de Brito 12 December 2002 (has links)
A tecnologia de conjugação melhorou a imunogeniddade de vacinas constituídas de polissacarídeo, especialmente em crianças. Polissacarídeos conjugados a proteínas carregadoras, como o toxóide tetânico, induzem resposta imunológica dependente de célula T e memória imunológica de longa duração. No entanto, esta tecnologia apresenta custo elevado. Assim, foi investigada a capaddade dos lipossomos de aumentar a resposta imunológica ao polissacarídeo C de Neisseria meningitidis (PSC). Camundongos foram imunizados com Iipossomos contendo PSC, conjugado toxóide tetânico-PSC ou PSC livre como controle, com dose de reforço constituída de PSC livre. Foram gerados anticorpos IgG e IgM contra PSC nos camundongos imunizados com conjugado ou Iipossomo. Os resultados mostram que lipossomos contendo PSC têm potencial para substituir a vadna conjugada toxóide tetânico-PSC. / Conjugation technology has improved the immunogenicity of polysaccharide vaccines, specially in small children. Polysaccharides conjugated to various carrier proteins, e.g. tetanus toxoid, stimulate a T cell-dependent antibody response and induce a long-term immunological memory. However, protein-polysaccharide conjugation technology is expensive and this could constitute an important drawback. Thus, immunopotentiation of Neisseria meningitidis serogroup C polysaccharide (PSC) by use of liposomes as an alternative to protein-polysaccharide C conjugates was investigated. Mice were immunized with liposomes containing PSC or tetanus toxoid-PSC conjugate or free PSC as control and boosted with free PSC. Immunogenicity of these different preparations was compared with each other. Conjugate and liposome containing PSC induced both IgG and IgM antibodies against the polysaccharide. These results show that liposomes containing entrapped PSC have potential to be used as an alternative to tetanus toxoid-PSC conjugate vaccine.
175

Caracterização do plasmídeo pVCM 04 extraídos de Salmonella enterica isolada de carcaçãs de frangos / Characterization of the plasmid extracted pVCM 04 of Salmonella enterica isolated from chicken carcasses

CARNEIRO, Lílian Carla 31 May 2010 (has links)
Made available in DSpace on 2014-07-29T15:10:31Z (GMT). No. of bitstreams: 1 Lilian CARLA CARNEIRO Tese.pdf: 936824 bytes, checksum: e49c7ff122a0392ea9e5120fd05064ed (MD5) Previous issue date: 2010-05-31 / A small cryptic plasmid isolated from Salmonella enterica Enteritidis called pVCM04 was sequenced and characterizated. pVCM04 is a 3583 pb circle molecule that showed no homology with other plasmids deposited in the GenBank. 12 ORF with more than 50 aminoacids were predicted using the ORF finder program. ORF1 and ORF2 showed homology with replication proteins of different plasmids. ORF 3-5 showed homology with mobilization proteins present in several plasmids; the others seven ORF showed no homology with genes deposited in GenBank. The pVCM04 possess a region with more than 500 pb that is not associated with none of the predicted proteins. This region is organizated in a G+C rich, A+T rich and two repeat direct sequences. The second repeat direct sequence contains a region of DnaA box connection (TTTACAC). This region is probably associated to the replication origin theta type. The phylogenetic relationship among replicase and mobilization deduced protein showed highest similarity of replicase proteins than mobilization proteins. Conjugation experiments showed that the pVCM04/pUC18 fusion not have a good ability to transfer, the plasmid stability test showed that the cells lost 60% of pVCM04/pUC18 on the first day of cultivation. The characterization suggests that the pVCM04 probably would be a cryptic plasmid from fusion of different ancestral plasmid. / Um pequeno plasmídeo críptico isolado de Salmonella enterica Enteretidis denominado pVCM04 foi sequênciado e caracterizado. O pVCM04 é uma molécula circular com 3583 pb a qual não apresenta homologia com outros plasmídeos depositados no GenBank . 12 ORF ( Open Read Frame ) com mais de 50 aminoácidos foram preditas usando o programa ORFinder. A ORF1 e a ORF2 apresentaram homologia com proteínas de replicação de diferentes plasmídeos. As ORF 3, 4 e 5 apresentaram homologia com proteínas de mobilização presente em vários plasmídeos; as outras sete ORF não apresentaram homologia com genes depositados no GenBank . O pVCM04 possui uma região, com mais de 500 pb, que não está associada a nenhuma das proteínas preditas. Esta região está organizada em uma sequência rica em G+C, A+T e duas sequências repetidas diretas. A segunda sequência repetida direta contém uma sequência de ligação para a proteína DnaA (TTTACAC). Esta região está provavelmente associada com a origem de replicação do tipo theta. As relações filogenéticas para as proteínas deduzidas replicase e de mobilização mostraram maior similaridade para proteínas replicase do que para proteínas de mobilização. Experimentos de conjugação evidenciaram que a fusão pVCM04&#8260;pUC18 não possui uma boa capacidade de transferência; o teste de estabilidade plasmidial demonstrou que as células perdem 60% do pVCM04&#8260;pUC18 no primeiro dia de cultivo. A caracterização do pVCM04 sugere que este plasmídeo provavelmente seja um plasmídeo críptico oriundo de diferentes ancestrais.
176

As formas verbais finitas do hebraico bíblico: qatal, yiqtol, wayyiqtol e weqatal e seus respectivos usos na narrativa e poesia bíblica / The biblical hebrew verbal finite forms: qatal, yiqtol, weqatal e wayyiqtol and its respective uses in biblical narrative and poetry

Tiago Rebello Perin 20 May 2016 (has links)
O sistema verbal do hebraico bíblico tem sido objeto de debate desde o início dos estudos gramaticais até os dias atuais. As conjugações de sufixo e prefixo, com ou sem a presença do waw prefixado (respectivamente, as formas verbais: qatal, yiqtol, weqatal e wayyiqtol) tomam uma parte central nesse debate devido à grande amplitude de significados que possuem na Bíblia Hebraica. A presente pesquisa propõe-se a apresentar as várias correntes teóricas acerca da interpretação do significado e relação dessas quatro formas verbais e também o uso das mesmas nos textos narrativos e poéticos da Bíblia Hebraica. / The verbal system of Biblical Hebrew has been the subject of debate since the beginning of grammatical studies until today. The suffix and prefix conjugations, with or without the presence of prefixed waw (respectively, the verbal forms: qatal, yiqtol, weqatal e wayyiqtol) take a central part in this debate because of the wide range of meaning that they have in the Hebrew Bible. This research aims to present the various theoretical perspectives about the interpretation of the meaning and relationship of these four verbal forms and also the use of each of them in narrative and poetic texts of the Hebrew Bible.
177

Beiträge zur chemisch-biologischen Oberflächenmodifikation von Nanodiamanten aus der Detonationssynthese

Pohl, Andrea 19 January 2018 (has links) (PDF)
Die vorliegende Arbeit behandelt die Oberflächenmodifikation von Nanodiamanten (ND) aus der Detonationssynthese und die anschließende Konjugation von einzel- bzw. doppelsträngiger DNA an die zuvor eingeführten funktionellen Gruppen. Als Ausgangsmaterialien wurden zwei Nanodiamantpulver mit unbekannter Oberflächenbelegung eingesetzt, deren Charakterisierung durch elektronenmikroskopische Methoden erfolgte. Weiterhin wurden kommerziell modifizierte ND mit definierter Oberflächenbelegung (Amino- und Hydroxylgruppen) verwendet. Für potenzielle Anwendungen von ND wird eine monofunktionale Oberfläche angestrebt, die u. a. über Oxidation oder Reduktion der durch den Herstellungsprozess eingeführten primären funktionellen Gruppen realisiert werden kann. Die dadurch erzeugten sekundären Funktionen ermöglichen die kovalente bzw. nichtkovalente Anbindung weiterer Substanzen, z. B. von Biomolekülen, an die Oberflächen der ND-Partikel. Die hier beschriebene Konjugation von DNA, an die mit Carboxyl-, Hydroxyl- oder Aminogruppen modifizierten Partikeloberflächen, erfolgte durch die Generierung von Amid-, Phosphodiester- und Isoharnstoffbindungen. Der Erfolg der Konjugationen wurde mit Hilfe von Infrarotspektroskopie und Fluoreszenzmikroskopie untersucht. Die Fluoreszenz der Konjugate beruhte dabei auf Fluoreszenzfarbstoffen, die an die DNA-Moleküle gebunden waren. Darüber hinaus wird die Herstellung einer kolloidalen ND-Suspension beschrieben, von der die Partikelgrößen und das Zeta-Potenzial bestimmt wurden. Kolloidale Suspensionen ermöglichen aufgrund der geringen Partikelgrößen diverse biologische und medizinische Anwendungen von ND. Mit den hier präsentierten Ergebnissen erweitert sich der Kenntnisstand zur Konjugation von DNA an ND aus der Detonationssynthese. Die angewandte Methodik kann ebenso auf andere Substanzen wie Proteine oder Chemotherapeutika übertragen werden. Derart funktionalisierte Partikel besitzen ein großes Potenzial für die weitere Anwendung in der Biomedizin und Nanotechnologie. / The present study deals with the surface modification of nanodiamonds (ND) from detonation synthesis and the subsequent conjugation of both single and double stranded DNA to previously introduced functional groups. As starting materials two kinds of nanodiamond powders with unknown surface configuration were used. Both types of ND were characterized by electron-microscopic methods. Furthermore, commercially modified ND with defined surface configuration (amino and hydroxyl groups) were applied. Potential applications of ND require a mono-functional surface, that can be realized e. g. via oxidation or reduction of the primary functional groups introduced during the production process. The thereby generated secondary functions permit the covalent or non-covalent linking of further substances onto the surfaces of ND particles. Conjugation of DNA, as described here, onto the carboxyl-, hydroxyl- or aminomodified particle surfaces was accomplished by generating of amino, phosphodiester and isourea bonds. The success of conjugations has been examined by infrared spectroscopy and fluorescence microscopy. The fluorescence of conjugates based on fluorescent dyes bound to the DNA molecules. Furthermore, the fabrication of a colloidal ND suspension is described, of which the particle sizes and the Zeta potential have been determined. Colloidal suspensions facilitate various biological and medical applications of ND on the basis of low particle sizes. The presented results enlarge the state of knowledge about the conjugation of DNA on ND from detonation synthesis. The applied methodology may also be transferred to other substances like proteins or chemotherapeutics. In this way, functionalized particles have a big potential for further application in biomedicine and nanotechnology.
178

Le plasmide Ti d’Agrobacterium fabrum C58 : analyse fonctionnelle d’ARN régulateurs / Agrobacterium fabrum C58 Ti plasmid : functional analysis of regulatory rna

Diel, Benjamin 18 September 2017 (has links)
L'expression des gènes peut être contrôlée à différents niveaux : transcriptionnel post-transcriptionnel, traductionnel et post­-traductionnel. A ce jour la majorité des études se sont concentrées au niveau transcriptionnel, néanmoins l'importance des mécanismes de régulation post-transcriptionnels se fait de plus en plus évidente. Chez les procaryotes cette régulation post-transcriptionnelle est assurée par les ARN régulateurs dont le mécanisme d'action passe par l'interaction directe avec les ARN messagers ou les protéines. Grâce à l'essor des analyses transcriptomiques haut-débit (RNA-seq), l'identification de ces ARN est devenue accessible, en revanche leur caractérisation fonctionnelle demeure toujours un défi. Nous avons identifié de nombreux ARN régulateurs candidats chez Agrobacterium fabrum C58 (anciennement Agrobacterium tumefaciens C58). Cette bactérie commune du sol devient phytopathogène lorsqu'elle porte le plasmide Ti (pour Tumor inducing). Elle est alors responsable de la maladie dite de la galle du collet qui se traduit par la formation de tumeurs chez les plantes. Ces travaux de thèse ont eu pour objectif de caractériser fonctionnellement des ARN régulateurs présent sur le plasmide Ti. Deux candidats ont été étudiés en combinant prédiction de cibles et analyses phénotypiques. Le premier, nommé RNA1111, a été caractérisé tant que régulateur de la virulence. Quant au deuxième, nommé QfsR, nous avons démontré qu'il régulait des gènes responsables du transfert conjugatif du plasmide Ti et de la production du signal de quorum sensing associé, mais également des gènes chromosomiques responsables de la motilité et de la production de succinoglycane. En utilisant un système rapporteur, nous avons également démontré que QfsR agissait via une interaction directe avec les ARN messagers des gènes cibles. QfsR représente le premier exemple d'ARN régulateur plasmidique régulant des cibles chromosomiques. L'existence d'un tel régulateur chez un plasmide présent transitoirement au sein des populations d'Agrobacterium illustre le dialogue entre plasmide et chromosome / Gene expression can be controlled at different levels: transcriptional, post-transcriptional, translational and post-translational. To date, the majority of studies have been concentrated on the transcriptional level, but the importance of post-transcriptional regulation mechanisms is becoming more and more evident. In prokaryotes this post-transcriptional regulation is ensured by regulatory RNAs whose mechanism of action passes through direct interaction with messenger RNAs or proteins. With development of high-throughput transcriptomic analyzes (RNA-seq), the identification of these RNAs has become accessible, but their functional characterization remains challenging. We have identified many candidate regulatory RNAs in Agrobacterium fabrum C58 (formerly Agrobacterium tumefaciens C58). This common bacterium of the soil becomes phytopathogenic when carrying the plasmid Ti (for Tumor inducing). It is then responsible for the so-called grown gall disease which results in the formation of tumors in plants. The objective of this thesis was to characterize functionally regulatory RNAs present on the Ti plasmid. Two candidates were studied by combining target prediction and phenotypic analysis. The first, named RNA1111, was characterized as a regulator of virulence. As for the second, named QfsR, we demonstrated that it regulates genes responsible for the conjugative transfer of the Ti plasmid and the production of the associated quorum sensing signal, as well as chromosomal genes responsible for the motility and succinoglycan production. Using a reporter system, we also demonstrated that QfsR was acting via direct interaction with the messenger RNAs of the target genes. QfsR represents the first example of plasmid regulatory RNA regulating chromosomal targets. The existence of such a regulator in a plasmid transiently present in the populations of Agrobacterium illustrates the dialogue between the plasmid and the chromosome
179

Site-specific glycoconjugate synthesis / Synthèse site-spécifique de glycoconjugués

Bayart, Caroline 08 December 2017 (has links)
Les vaccins conjugués furent développés suite à l’inefficacité des vaccins polysaccharidiques chez les nourrissons et les personnes âgées. Les vaccins conjugués sont composés d’un polysaccharide extrait de la capsule bactérienne et d’une protéine porteuse. Celle-ci permet de décupler la réponse immunitaire, permettant aux vaccins d’être efficaces. L’évolution des connaissances en chimie et en analytique permettent aujourd’hui de mieux caractériser ces vaccins et de mieux maîtriser leur production. Cependant, les chimies de conjugaison utilisées pour lier le polysaccharide et la protéine porteuse, ne sont pas toujours définies et cela mène souvent à l’obtention de produits hétérogènes. Les objectifs de cette thèse ont été d’étudier le polysaccharide, les protéines porteuses et de nouvelles voies de conjugaisons pour lier spécifiquement ces deux biomolécules.Différents outils analytiques ont été utilisés afin d’acquérir une meilleure connaissance des deux partenaires de conjugaison. Cela a également permis d’établir une stratégie d’analyse efficace pour caractériser les produits de réaction. La spécificité des réactions de conjugaison a été induite par l’utilisation d’espaceurs bi-fonctionnels, réagissant spécifiquement sur certains acides aminés. Leur réactivité a d’abord été testée sur un modèle peptidique. Cela a permis de faciliter la caractérisation et d’étudier l’efficacité et la spécificité des réactions. Les réactions efficaces ont ensuite été testées différents modèles : de la protéine au vaccin. Sur les quatre réactions testées, une a été efficace sur tous les modèles. Cette chimie de conjugaison est prometteuse pour le développement de nouveaux vaccins / Conjugate vaccines were developed because polysaccharide vaccines were not efficient in infant and old people. These vaccines were composed of the polysaccharide extracted from the bacterial capsule linked to a carrier protein. This protein created an immunological boost which allowed the vaccine to induce a proper protection for everyone. As chemistry knowledge and analytical techniques evolved, vaccines can now be better characterized and the production can be better controlled. Nevertheless, the chemistries used to bind the polysaccharide and the carrier protein are not always well-defined, which leads to the production of heterogeneous products. The objectives of this PhD were to study the polysaccharide, carrier proteins and new conjugation chemistries to specifically bind the two biomolecules. The other challenge was to be able to check the reaction specificity and characterize reaction products.To do so different analytical tools were used to allow a better knowledge of both conjugation partners but also to establish an efficient analytical strategy for glycoconjugate characterization. Conjugation reactions specificity was induced by using different bi-functional linkers, reacting specifically for one type of amino acid. Linkers’ reactivity was first tested on a model peptide. This allowed to facilitate the characterization and to check for both reaction specificity and reaction success. Efficient reactions were then tested on different models from carrier proteins to glycoconjugate vaccines. One of the four tested reactions was efficient from the peptide to the vaccine model. This conjugation is thus promising for the development of new conjugate vaccines
180

Beiträge zur chemisch-biologischen Oberflächenmodifikation von Nanodiamanten aus der Detonationssynthese

Pohl, Andrea 04 August 2017 (has links)
Die vorliegende Arbeit behandelt die Oberflächenmodifikation von Nanodiamanten (ND) aus der Detonationssynthese und die anschließende Konjugation von einzel- bzw. doppelsträngiger DNA an die zuvor eingeführten funktionellen Gruppen. Als Ausgangsmaterialien wurden zwei Nanodiamantpulver mit unbekannter Oberflächenbelegung eingesetzt, deren Charakterisierung durch elektronenmikroskopische Methoden erfolgte. Weiterhin wurden kommerziell modifizierte ND mit definierter Oberflächenbelegung (Amino- und Hydroxylgruppen) verwendet. Für potenzielle Anwendungen von ND wird eine monofunktionale Oberfläche angestrebt, die u. a. über Oxidation oder Reduktion der durch den Herstellungsprozess eingeführten primären funktionellen Gruppen realisiert werden kann. Die dadurch erzeugten sekundären Funktionen ermöglichen die kovalente bzw. nichtkovalente Anbindung weiterer Substanzen, z. B. von Biomolekülen, an die Oberflächen der ND-Partikel. Die hier beschriebene Konjugation von DNA, an die mit Carboxyl-, Hydroxyl- oder Aminogruppen modifizierten Partikeloberflächen, erfolgte durch die Generierung von Amid-, Phosphodiester- und Isoharnstoffbindungen. Der Erfolg der Konjugationen wurde mit Hilfe von Infrarotspektroskopie und Fluoreszenzmikroskopie untersucht. Die Fluoreszenz der Konjugate beruhte dabei auf Fluoreszenzfarbstoffen, die an die DNA-Moleküle gebunden waren. Darüber hinaus wird die Herstellung einer kolloidalen ND-Suspension beschrieben, von der die Partikelgrößen und das Zeta-Potenzial bestimmt wurden. Kolloidale Suspensionen ermöglichen aufgrund der geringen Partikelgrößen diverse biologische und medizinische Anwendungen von ND. Mit den hier präsentierten Ergebnissen erweitert sich der Kenntnisstand zur Konjugation von DNA an ND aus der Detonationssynthese. Die angewandte Methodik kann ebenso auf andere Substanzen wie Proteine oder Chemotherapeutika übertragen werden. Derart funktionalisierte Partikel besitzen ein großes Potenzial für die weitere Anwendung in der Biomedizin und Nanotechnologie.:1 Einleitung 1 2 Theoretische Grundlagen 6 2.1 Nanodiamant 7 2.1.1 Historische Betrachtungen zur Detonationssynthese 7 2.1.2 Herstellung von Diamant 8 2.1.3 Aufbereitung von Nanodiamanten aus der Detonationssynthese 11 2.1.4 Struktur und Eigenschaften von Diamant 12 2.1.5 Homogenisierung der Oberflächenbelegung 16 2.1.6 Aggregation und Deaggregation von Nanodiamant-Partikeln 20 2.1.7 Anwendungen von Nanodiamant-Partikeln 21 2.2 Aptamere 26 2.2.1 Strukturbildung und Bindungsmechanismen 26 2.2.2 Zielsubstanzen 28 2.2.3 Vergleich von Aptameren und Antikörpern 29 2.2.4 Herstellung von Aptameren – Der SELEX-Prozess 32 2.2.5 Anwendungsfelder für Aptamere 34 2.3 Konjugation von Nanopartikeln mit Biomolekülen 38 2.4 Herstellung und Charakterisierung von kolloidalen Nanodiamantsuspensionen 46 2.4.1 Herstellung kolloidaler Nanodiamantsuspensionen 46 2.4.2 Bestimmung der Partikelgröße und Partikelgrößenverteilung durch dynamische Lichtstreuung (DLS) 47 2.4.3 Bestimmung des Zeta-Potenzials durch elektrophoretische Licht-streuung (ELS) 48 2.5 Methoden zur Materialcharakterisierung von Nanodiamantpulver 52 2.5.1 Rasterelektronenmikroskopie (REM) 52 2.5.2 Energiedispersive Röntgenspektroskopie (EDX) 53 2.5.3 Transmissionselektronenmikroskopie (TEM) 54 2.6 Nachweismethoden für Modifikation und Konjugatbildung 56 2.6.1 Fourier-Transform-Infrarot- (FT-IR-) Spektroskopie 56 2.6.2 Fluoreszenzmikroskopie 60 3 Material und Methoden 62 3.1 Herstellung und Charakterisierung von kolloidalen Nanodiamantsuspensionen 62 3.1.1 Herstellung kolloidaler Nanodiamantsuspensionen 62 3.1.2 Bestimmung von Partikelgröße, Partikelgrößenverteilung und Zeta-Potenzial 63 3.2 Materialcharakterisierung von Nanodiamantpulver 64 3.2.1 Rasterelektronenmikroskopie (REM) 64 3.2.2 Energiedispersive Röntgenspektroskopie (EDX) 65 3.2.3 Hochauflösende Transmissionselektronenmikroskopie (HRTEM) 65 3.3 Chemische Modifikation von Nanodiamanten 66 3.3.1 Verwendete Materialien und Geräte 67 3.3.2 Einführung von Carboxylgruppen 68 3.3.3 Einführung von Hydroxylgruppen 69 3.3.4 Einführung von Aminogruppen 70 3.4 Herstellung von Nanodiamant-Aptamer-Konjugaten 73 3.4.1 Verwendete Materialien und Geräte 73 3.4.2 Konjugation über Amidbindungen 77 3.4.3 Konjugation über Ester- und Phosphodiesterbindungen 81 3.4.4 Konjugation über Isoharnstoffbindungen 85 3.5 Nachweismethoden für Modifikation und Konjugatbildung 88 3.5.1 Fourier-Transform-Infrarot- (FT-IR-) Spektroskopie 88 3.5.2 Fluoreszenzmikroskopie 89 4 Ergebnisse und Diskussion 92 4.1 Charakterisierung kolloidaler Nanodiamantsuspensionen 92 4.1.1 Bestimmung der Partikelgröße und Partikelgrößenverteilung 92 4.1.2 Bestimmung des Zeta-Potenzials 93 4.2 Materialcharakterisierung von Nanodiamantpulvern 98 4.2.1 Rasterelektronenmikroskopie (REM) 98 4.2.2 Energiedispersive Röntgenspektroskopie (EDX) 101 4.2.3 Hochauflösende Transmissionselektronenmikroskopie (HRTEM) 107 4.3 Fourier-Transform-Infrarot- (FT-IR-) Spektroskopie 117 4.3.1 Nanodiamanten: Originalmaterial und modifizierte Nanodiamanten 118 4.3.1.1 Nanodiamanten – Originalmaterial 118 4.3.1.2 Modifikation mit Carboxylgruppen (ND-COOH) 122 4.3.1.3 Modifikation mit Hydroxylgruppen (ND-OH) 123 4.3.1.4 Modifikation mit Aminogruppen (ND-NH2) 128 4.3.2 Nanodiamant-DNA-Konjugate 138 4.3.2.1 Konjugation über Amidbindungen 140 4.3.2.2 Konjugation über Phosphodiesterbindungen 144 4.3.2.3 Konjugation über Isoharnstoffbindungen 150 4.4 Fluoreszenzmikroskopie an Nanodiamant-DNA-Konjugaten 154 4.4.1 Konjugation über Amidbindungen 154 4.4.2 Konjugation über Phosphodiesterbindungen 157 4.4.3 Konjugation über Isoharnstoffbindungen 161 5 Zusammenfassung und Ausblick 165 6 Literaturverzeichnis 170 Anhang I A-1 Parameter der Partikelgrößen- und Zeta-Potenzial-Messungen I A-2 Nukleotidsequenz von EF1a III A-3 GFP-Filter-Spektrum IV A-4 FT-IR-Spektren von Nanodiamanten V A-5 FT-IR-Spektren von Nanodiamant-DNA-Konjugaten X Verzeichnis der Formelzeichen XIV Abkürzungsverzeichnis XV Eigene wissenschaftliche Beiträge XVIII Danksagung Erklärung / The present study deals with the surface modification of nanodiamonds (ND) from detonation synthesis and the subsequent conjugation of both single and double stranded DNA to previously introduced functional groups. As starting materials two kinds of nanodiamond powders with unknown surface configuration were used. Both types of ND were characterized by electron-microscopic methods. Furthermore, commercially modified ND with defined surface configuration (amino and hydroxyl groups) were applied. Potential applications of ND require a mono-functional surface, that can be realized e. g. via oxidation or reduction of the primary functional groups introduced during the production process. The thereby generated secondary functions permit the covalent or non-covalent linking of further substances onto the surfaces of ND particles. Conjugation of DNA, as described here, onto the carboxyl-, hydroxyl- or aminomodified particle surfaces was accomplished by generating of amino, phosphodiester and isourea bonds. The success of conjugations has been examined by infrared spectroscopy and fluorescence microscopy. The fluorescence of conjugates based on fluorescent dyes bound to the DNA molecules. Furthermore, the fabrication of a colloidal ND suspension is described, of which the particle sizes and the Zeta potential have been determined. Colloidal suspensions facilitate various biological and medical applications of ND on the basis of low particle sizes. The presented results enlarge the state of knowledge about the conjugation of DNA on ND from detonation synthesis. The applied methodology may also be transferred to other substances like proteins or chemotherapeutics. In this way, functionalized particles have a big potential for further application in biomedicine and nanotechnology.:1 Einleitung 1 2 Theoretische Grundlagen 6 2.1 Nanodiamant 7 2.1.1 Historische Betrachtungen zur Detonationssynthese 7 2.1.2 Herstellung von Diamant 8 2.1.3 Aufbereitung von Nanodiamanten aus der Detonationssynthese 11 2.1.4 Struktur und Eigenschaften von Diamant 12 2.1.5 Homogenisierung der Oberflächenbelegung 16 2.1.6 Aggregation und Deaggregation von Nanodiamant-Partikeln 20 2.1.7 Anwendungen von Nanodiamant-Partikeln 21 2.2 Aptamere 26 2.2.1 Strukturbildung und Bindungsmechanismen 26 2.2.2 Zielsubstanzen 28 2.2.3 Vergleich von Aptameren und Antikörpern 29 2.2.4 Herstellung von Aptameren – Der SELEX-Prozess 32 2.2.5 Anwendungsfelder für Aptamere 34 2.3 Konjugation von Nanopartikeln mit Biomolekülen 38 2.4 Herstellung und Charakterisierung von kolloidalen Nanodiamantsuspensionen 46 2.4.1 Herstellung kolloidaler Nanodiamantsuspensionen 46 2.4.2 Bestimmung der Partikelgröße und Partikelgrößenverteilung durch dynamische Lichtstreuung (DLS) 47 2.4.3 Bestimmung des Zeta-Potenzials durch elektrophoretische Licht-streuung (ELS) 48 2.5 Methoden zur Materialcharakterisierung von Nanodiamantpulver 52 2.5.1 Rasterelektronenmikroskopie (REM) 52 2.5.2 Energiedispersive Röntgenspektroskopie (EDX) 53 2.5.3 Transmissionselektronenmikroskopie (TEM) 54 2.6 Nachweismethoden für Modifikation und Konjugatbildung 56 2.6.1 Fourier-Transform-Infrarot- (FT-IR-) Spektroskopie 56 2.6.2 Fluoreszenzmikroskopie 60 3 Material und Methoden 62 3.1 Herstellung und Charakterisierung von kolloidalen Nanodiamantsuspensionen 62 3.1.1 Herstellung kolloidaler Nanodiamantsuspensionen 62 3.1.2 Bestimmung von Partikelgröße, Partikelgrößenverteilung und Zeta-Potenzial 63 3.2 Materialcharakterisierung von Nanodiamantpulver 64 3.2.1 Rasterelektronenmikroskopie (REM) 64 3.2.2 Energiedispersive Röntgenspektroskopie (EDX) 65 3.2.3 Hochauflösende Transmissionselektronenmikroskopie (HRTEM) 65 3.3 Chemische Modifikation von Nanodiamanten 66 3.3.1 Verwendete Materialien und Geräte 67 3.3.2 Einführung von Carboxylgruppen 68 3.3.3 Einführung von Hydroxylgruppen 69 3.3.4 Einführung von Aminogruppen 70 3.4 Herstellung von Nanodiamant-Aptamer-Konjugaten 73 3.4.1 Verwendete Materialien und Geräte 73 3.4.2 Konjugation über Amidbindungen 77 3.4.3 Konjugation über Ester- und Phosphodiesterbindungen 81 3.4.4 Konjugation über Isoharnstoffbindungen 85 3.5 Nachweismethoden für Modifikation und Konjugatbildung 88 3.5.1 Fourier-Transform-Infrarot- (FT-IR-) Spektroskopie 88 3.5.2 Fluoreszenzmikroskopie 89 4 Ergebnisse und Diskussion 92 4.1 Charakterisierung kolloidaler Nanodiamantsuspensionen 92 4.1.1 Bestimmung der Partikelgröße und Partikelgrößenverteilung 92 4.1.2 Bestimmung des Zeta-Potenzials 93 4.2 Materialcharakterisierung von Nanodiamantpulvern 98 4.2.1 Rasterelektronenmikroskopie (REM) 98 4.2.2 Energiedispersive Röntgenspektroskopie (EDX) 101 4.2.3 Hochauflösende Transmissionselektronenmikroskopie (HRTEM) 107 4.3 Fourier-Transform-Infrarot- (FT-IR-) Spektroskopie 117 4.3.1 Nanodiamanten: Originalmaterial und modifizierte Nanodiamanten 118 4.3.1.1 Nanodiamanten – Originalmaterial 118 4.3.1.2 Modifikation mit Carboxylgruppen (ND-COOH) 122 4.3.1.3 Modifikation mit Hydroxylgruppen (ND-OH) 123 4.3.1.4 Modifikation mit Aminogruppen (ND-NH2) 128 4.3.2 Nanodiamant-DNA-Konjugate 138 4.3.2.1 Konjugation über Amidbindungen 140 4.3.2.2 Konjugation über Phosphodiesterbindungen 144 4.3.2.3 Konjugation über Isoharnstoffbindungen 150 4.4 Fluoreszenzmikroskopie an Nanodiamant-DNA-Konjugaten 154 4.4.1 Konjugation über Amidbindungen 154 4.4.2 Konjugation über Phosphodiesterbindungen 157 4.4.3 Konjugation über Isoharnstoffbindungen 161 5 Zusammenfassung und Ausblick 165 6 Literaturverzeichnis 170 Anhang I A-1 Parameter der Partikelgrößen- und Zeta-Potenzial-Messungen I A-2 Nukleotidsequenz von EF1a III A-3 GFP-Filter-Spektrum IV A-4 FT-IR-Spektren von Nanodiamanten V A-5 FT-IR-Spektren von Nanodiamant-DNA-Konjugaten X Verzeichnis der Formelzeichen XIV Abkürzungsverzeichnis XV Eigene wissenschaftliche Beiträge XVIII Danksagung Erklärung

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