Дисертації з теми "Encapsulation of molecules of interest"

Ce travail porte sur la préparation de matériaux silicatés à porosité hiérarchisée pour l'encapsulation de molécules d'intérêt dans le domaine de la pharmacie et en tant que biocatalyseur. Afin d’atteindre cet objectif, les nano-émulsions sont choisies comme empreinte pour créer les macropores du matériau en raison de la taille homogène et réduite des gouttelettes de l’émulsion (inférieure à 100 nm). Pour cela le système Remcopal 4/décane/eau est investi en déterminant les conditions les plus optimales de formation de nano-émulsion, via les méthodes d'inversion de phases. L’ajout de micelles aux nano-émulsions ne déstabilise pas les émulsions et permet la formation d’un réseau de mésopores organisés selon une symétrie hexagonale. Les matériaux hybrides issus des matériaux poreux contenant encore la phase organique sont dopés par le ketoprofène en vue d’étudier la libération de ce dernier. Celle-ci se révèle sensible au pH. De plus, cette étude de la libération du kétoprofène à partir du matériau méso-macroporeux indique qu'elle est assistée par les micelles qui sont solubilisées dans la solution réceptrice. Le deuxième objectif de ce travail est d'utiliser ces matériaux poreux en tant que biocatalyseur pour la synthèse de biodiesel à partir d'huile de colza. Pour cette application, il est nécessaire que les matériaux résistent à l’immersion dans des milieux aqueux. L’étude de la stabilité hydrothermale a montré que le matériau calciné présente la meilleure stabilité dans l’eau bouillante. Par ailleurs, le matériau peut résister jusqu’à 550°C, la structure ne subissant que des dégradations mineures. Nous avons également utilisé un matériau silicaté à double mésoporosité préparé à partir de micelles fluorées et hydrogénées coexistant dans une même solution. L'évaluation thermique et hydrothermale indique que ces matériaux présentent deux cinétiques de déstructuration qui correspondent à chacune des deux matrices ayant deux tailles de pores différents. L’immobilisation de la lipase Mml est étudiée sur le matériau méso-macroporeux calciné et sur le matériau à double mésoporosité. Les isothermes d'adsorption ont permis de mettre en évidence que le matériau à double mésoporosité peut encapsuler plus d’enzymes que son homologue méso-macroporeux. L’activité enzymatique, au regard des réactions de transestérification, est de façon inverse plus importante avec le matériau méso-macroporeux calciné
This work concerns the preparation of silica materials with hierarchical porosity for the encapsulation of molecules of interest in the field of drug delivery and as biocatalysts. In order to reach this goal, the nano-emulsions were chosen as templates for the macropores of the material because of the homogeneous and small size of the emulsion droplets (less than 100 nm). The system Remcopal 4/decane/water was investigated and the optimal conditions for which nano-emulsion is formed via the phase inversion methods were determined. Adding micelles to the nano-emulsions does not affect its stability and can form a network of mesopores organized with a hexagonal symmetry. Hybrid materials which are hierarchically porous materials where the organic phase is still present, were doped with ketoprofen to study its release, which proved to be pH sensitive. Moreover, the study of the release of ketoprofen from the meso-macroporous material indicates that it is assisted by the micelles which are solubilized in the release medium. The second objective of this work was to use these porous materials as a biocatalyst for biodiesel synthesis from colza oil. For this application it was necessary that the materials are resistant to immersion in aqueous media. The study of the hydrothermal stability shows that the calcined material has the best stability in boiling water. Moreover, the material can withstand up to 550 ° C, the structure undergoes only minor damages. We also used a dual-mesoporous silica material prepared from hydrogenated and fluorinated micelles coexisting in the same solution. Thermal and hydrothermal evaluation indicates that these materials have two different decay kinetics corresponding to each of the two matrices having different pore sizes. The immobilization of lipase Mml was studied on the meso-macroporous calcined material and the dual-mesoporous material. The adsorption isotherms were used to demonstrate that the dual-mesoporous material can encapsulate more enzymes than its meso-macroporous counterpart. On the other hand, the enzyme activity, evaluated by the transesterification reactions, is more important for the calcined meso-macroporous material

Ce travail est consacré à l’élaboration de matériaux permettant le relargage contrôlé de molécules d’intérêt. Dans la première partie de ce projet, des synthèses d’hybrides organiqueinorganique de structure de type talc ont été réalisées avec différentes sources de silicium, ce qui induit des cristallinités et des degrés de condensation différentes des espèces siliciques. Ces hybrides ont ensuite été caractérisés. La présence d’acide folique (molécule d’intérêt) dans le milieu de synthèse permet son encapsulation dans l’hybride. L’incorporation d’acide folique n’induit pas de changements significatifs dans la structure des hybrides formés. Les différentes techniques de caractérisation ont permis de montrer que l’acide folique est peu mobile dans la structure et est donc bien encapsulé dans l’interfoliaire des hybrides. Au niveau du relargage, les hybrides induisent un relargage rapide, que ce soit dans l’eau ou dans un sol modèle. Les hybrides préparés à partir de N2TMS (N-[3-(triméthoxysilyl))propyl]éthylènediamine) permettent le relargage le plus rapide tandis que ceux synthétisés avec du C16TMS (Hexadécyltriméthoxysilane) présentent le relargage le plus lent. Ceci est attribué au caractère fortement hydrophobe de la chaine organique dans l’interfoliaire. La deuxième partie de la thèse a permis de tester plusieurs matériaux qui pourrait conduire à du relargage photo-contrôlé de principes actifs. Les matériaux hybrides synthétisés à partir de NBATES (3-(triéthoxysilylpropyl)-4-nitrobenzamide) ont montré des résultats prometteurs : sous irradiation UV à 254 nm, le taux de relargage d’une molécule modèle est en effet deux fois plus élevé qu’en absence de lumière. Pour les hybrides élaborés à partir de MCTES (O-4-methylcoumarinyl-N-[3-(triéthoxysilyl)propyl]carbamate), les meilleurs résultats ont été obtenus avec une irradiation UV à 365 nm. Les groupes fonctionnels photosensibles présents dans les hybrides de type talc permettent en effet de rendre les composites photosensibles. Ces résultats prometteurs pourront être développés par la suite pour des applications dans le domaine agricole
This work is devoted to the development of materials allowing the controlled release of molecules of interest. In the first part of this project, syntheses of organic-inorganic hybrids having a talc type structure were carried out with different silica sources, which induces variable crystallinity and polycondensation of silicic species. These hybrids were then characterized. The folic acid (molecule of interest) once added to the synthesis medium was encapsulated into the hybrid. The incorporation of folic acid does not induce significant changes in the structure of the hybrids formed. The different characterization techniques have shown that the folic acid is not very mobile in the structure and is therefore well encapsulated in the interlayer space of the hybrids. The hybrids showed a fast releasing kinetics, both in water or in a model soil. Hybrids prepared from N2TMS (N- [3-(trimethoxysilyl))propyl]ethylenediamine) showed the fastest release, while those synthesized with C16TMS (Hexadecyltrimethoxysilane) exhibited the slowest releasing kinetics due to the highly hydrophobic nature of the organic chain of the hybrid. The second part of the thesis was focused on finding and testing materials potentially active in the photo-controlled release of active molecules. The hybrid materials synthesized from NBATES (3-(triethoxysilylpropyl)-4- nitrobenzamide) have shown promising results: under UV irradiation at 254 nm, the quantity released of a model molecule was indeed two times higher than that measured in the absence of light. For the hybrids synthesized from MCTES (O-4-methylcoumarinyl-N-[3- (triethoxysilyl)propyl]carbamate), the best results was obtained under UV irradiation at 365 nm. The photosensitive functional groups present in the talc type hybrids made possible to obtain photosensitive composites. These promising results are the base for further developments in agricultural applications

Three nanoparticle systems were investigated for the nano-encapsulation and release of bioactive molecules. The first series of hydroxyethyl methacrylate-co-carboxyethyl acrylate random polymers were found, above their critical aggregation concentration (CAC), to self-assemble into spherical nanoparticles which dissociated when the external pH rose above 4. The second and third series were core:shell microgels, crosslinked with ethylene glycol dimethacrylate (EGDMA), made from a core composed of hydroxyethyl methacrylate (HEMA) and a carboxyethyl acrylate (CEA) shell which underwent volume transitions when the external solution was raised above pH 4. These nanoparticle systems were investigated using proton NMR, zeta-potential, dynamic light scattering (DLS), potentiometric titrations, gel permeation chromatography (GPC) and turbidity studies. The shape, morphology and core:shell architecture were imaged using transmission electron microscopy (TEM) staining with uranyl acetate and phosphotungstic acid (PTA), Cryo-TEM, scanning electron microscopy (SEM), cryo-SEM, confocal microscopy and optical microscopy. The micro gels were all shown to have good biocompatibility by slug mucosal tests. The uptake and release of three dyes; Rhodamine 6G, Coumarin 153, and 9-diethylamino-5-benzo[a]phenoxazinone (Nile red) were investigated. High uptake of the dye molecules was observed at pH 4 and high release at pH 7, with microgel particle separation from the aqueous solution being achieved by centrifugation. The micro gel systems were investigated for the uptake of the model pharmaceuticals paracetamol, caffeine, dopamine, ibuprofen, carbamazepine and riboflavin; all of which have been detected globally in drinking water supplies. The uptake of pharmaceuticals by the microgel systems was shown to be low at both pH 4 and pH 7. The low uptake was concluded to be caused by the carboxylic acids groups localised on the microgel surface creating a collapsed skin layer, so inhibiting the inward diffusion of additional drugs. The uptake and release experiments were performed using spectrofluorescence analysis and UV -visible spectrometry. All three nanoparticulate systems were filterable from aqueous media at low (15 psi) pressure using lab-cast polyethersulphone (PES) ultrafiltration membranes with a molecular weight cut off (MWCO) of 10kDa.

The use of highly-energetic iOIl: beams for treating cancerous tumours is of increasing importance. In this study the damage caused to plasmid DNA by HO and H+ beams was investigated. Damage to dry DNA samples as a function of dose was assessed using gel electrophoresis. Results show enhanced levels of damage relative to that of x-rays and demonstrate an increase in damage with beam energy. Additionally, a considerable dependence on sample structure was shown. X-ray irradiation work has shown that doping samples with gold nanoparticles greatly enhances DNA damage and could enhance the effectiveness of cancer treatment. Hence in this study, damage to DNA samples containing gold nanoparticles was investigated, however, no enhancement was observed. TOF-MS was used to investigate fragment damage profiles at a molecular level. High-mass fragments corresponding to basal cleavage were not observed. Significant buffer residues in the dried samples were seen and identified. A model of DNA damage as a function of dose was constructed, providing quantitative conclusions about the effects of both gold nanoparticles and the different buffers used. Most of the energy deposited in the body by ionising radiation is absorbed by water molecules, leading to radical formation and, potentially, subsequent DNA damage. Current damage models use information on energy loss rates with penetration depth instead of information on radical production. In this work, fundamental fragmentation processes of water molecules irradiated with H+, HO and carbon ions and atoms were investigated. It was shown that it is imperative to consider the damage caused by fast neutrals in any dose profile modelling. Additionally, results for the ion production rate, to which free-radical production relates directly, show it is actually relatively uniform at a region where the ions come to rest and is not as sharply localised as suggested by the Bragg peak energy loss profiles.

El color juega un papel importante en nuestra vida diaria y no solo desde un punto de vista estético. Existe un gran mercado centrado en las aplicaciones tecnológicas derivadas del color, el cual engloba desde sus usos clásicos en colorantes y pigmentos hasta monitores, LEDs, almacenamiento óptico de datos y optoelectrónica, entre otros. En particular, la comunidad de materiales inteligentes ha dedicado especial atención al desarrollo de sistemas capaces de presentar una variación de color reversible al aplicar estímulos externos y a los cambios derivados en otras propiedades físicas, lo que se denomina cromismo. En esta tesis nos hemos interesados particularmente en colorantes orgánicos que exhiban propiedades fotocrómicas y termocrómicas, es decir, cambios de color inducidos por exposición a la luz o variaciones de temperatura. Estos compuestos poseen una gran variedad de aplicaciones potenciales; sin embargo no pueden ser aplicados directamente ya que en muchos casos sus propiedades crómicas características en disolución se ven modificadas, ralentizadas o inhibidas cuando son introducidos en materiales sólidos. El objetivo de esta tesis es proponer y explorar una nueva metodología capaz de solventar estos inconvenientes y permitir la transferencia directa de las propiedades fotocrómicas y termocrómicas observadas en disolución al estado sólido. Básicamente, nuestra aproximación consiste en la encapsulación de compuestos foto- y termocrómicos en el interior de cápsulas poliméricas con núcleos líquidos, capaces de preservar el comportamiento crómico característico en solución y ofrecer la posibilidad de introducir estos sistemas en matrices sólidas en las cuales el cambio del color se vería inhibido de ser incorporados de forma directa. Aplicando la aproximación propuesta, tres tipos diferentes de materiales fotoactivos han sido desarrollados a lo largo de esta tesis: (i) recubrimientos fotocrómicos de respuesta rápida con fines fotoprotectores, (ii) materiales sólidos termocrómicos basados en tautoméros de valencia, (iii) y sistemas sólidos basados en fluoróforos termosensibles capaces de emitir luz blanca sintonizable.
Colour plays an important role in our everyday live and not only from an aesthetic point of view. There is a big market centred in technological applications derived from chromic phenomena and colour science, encompassing from the classical commercial uses of dyes and pigments to visual displays, light emitting diodes, optical data storage and optoelectronics, among others. Particularly, the smart materials community has paid special attention to systems exhibiting a reversible colour change upon application of external stimuli and the variations that this induces in other physical properties- namely, chromism. In this thesis we have been particularly interested in photochromic and thermochromic organic dyes whose colour-tunability is induced by light irradiation and heat, respectively. These compounds present a wide range of potential applications; however, their usage is not straightforward since in many cases the well-established chromic properties of these species in solution are modified, slowed down or prevented when applied in solid materials. The aim of this thesis is to propose and explore a novel methodology to address this issue and allow the direct transfer of photo- and thermochromic properties from solution to the solid state. Basically, it consists in the encapsulation of the photo- and thermochromic compounds of interest inside liquid-filled polymeric capsules, which should preserve their solution-like chromic behaviour and offer the possibility to introduce these systems into any type of matrix that would restrain their colour tunability when directly incorporated. As proof of concepts of this strategy, three specific types of photoactive systems have been developed along this thesis: (i) fast-responsive photochromic coatings for photoprotective purposes, (ii) solid thermochromic materials made of valence tautomers, and (iii) white-light colour-tunable materials based on thermoresponsive fluorophores.

There is increasing clinical need for bone substitutes because of the limited supply of autogenous tissue, and the significance of inherited or other bone diseases. The ultimate aim of this study was to form calcium phosphate (CaP) based matrices as bone grafts for medical applications. Amongst CaP based materials, CaP gels made by the sol-gel process have attracted much interest since they can be processed at room temperature allowing the incorporation of environmentally sensitive molecules such as growth factors. CaP gels can be engineered by changing process conditions. There is little previous work however on the effect of drying regimes on the CaP materials formed using the sol-gel process. The objectives of this research were to investigate the influence of drying conditions on the physicochemical properties of CaP gels and the effect of the resultant structures of CaP gels on the function of the incorporated therapeutic molecules. In addition, surface modification of the CaP gels was investigated as a means to enhance biological interaction and also a potential way of creating primary bonds between apatite crystals enabling mechanical reinforcement of the material, which is currently too weak to bear load. This work has confirmed that different drying regimes have a significant influence on the formation of the gel pore structure, with the storage of gel in humid conditions, enabling reprecipitation of an apatitic phase. This variation in pore structure has a significant influence on the catalytic of encapsulated enzymes. In addition, the pH fluctuation of CaP based matrices during processing determines the activity of biomolecules after incorporation. It has also been shown that it is possible to form thiol functional groups on the surface of CaP gels, which could be used in future for mechanical reinforcement or for the attachment of biological moieties.

Le spectre d'absorption de molécules d'intérêt atmosphérique a été enregistré et analysé à l'aide de techniques expérimentales de très haute sensibilité : la technique ICLAS (Intracavity laser absorption spectroscopy) près de 1 æm, la spectroscopie par transformée de Fourier et la technique CW-CRDS (Cavity Ring Down Spectroscopy) dans l'infrarouge moyen. L'analyse et l'attribution rovibrationnelles des nombreuses bandes nouvelles 13CO2, ont été réalisées sur la base d'un Hamiltonien rovibrorationnel effectif. Un nouvel ajustement global tenant compte de nos nouvelles données et de toutes les données disponibles dans la littérature a été réalisée pour 13C16O2 et 16O13C18O. L'intensité absolue de sept bandes de 13C16O2 a aussi été mesurée. L'analyse spectroscopique de la structure vibrationnelle de SiHCI3 et rovibrationnelle de bandes de H70GeD3, DOCI and H2S est aussi présentée. Les paramètres rovibrationnels ont pu être déterminés pour les bandes faibles observées et des interactions rovibrationnelles fortes ont été mises en évidence et modélisées
The present work is devoted to the recording and anlysis of highly excited vibrational state of molecules of atmospheric interest with several high sensitive absorption techniques : intracavity laser absorption spectrometry (ICLAS) based on a Vertical External Cavity Surface Emitting Lasers (VeCSEL) near 1 æm, Fourier transform spectroscopy and cw-Cavity Ring Down Spectroscopy in the mid-infrared region. For 13CO2, the rotational analysis and vibrational assignments of the observed upper states have been performed on the basis of predictions of the effective Hamiltonian. New global fittings of the line positions of by gathering the present line positions with prévious measurements were performed for 13C16O2 and 16O13C18O. The parameters of the reduced effective Hamiltonian were derived. Line intensities of seven 13C16O2 bands were also recorded. The vibrational structure of SiHCI3 and rotational analysis of other molecules (H70GeD3, DOCI and H2S) are also presented. Their rovibrational parameters are obtained and strong interactions are evidenced and analized for most of the studied bands

Ce travail de thèse a pour objectif une meilleure connaissance des formulations filmogènes développées par les Laboratoires URGO. Deux aspects ont été développés.Il a tout d’abord été recherché un système d’encapsulation afin de protéger des molécules d’intérêt dans des solutions filmogènes. Des polymersomes en phase aqueuses et en phase organique ont été développés à base de copolymères amphiphiles m-PEG-PCL synthétisés et caractérisés au laboratoire. Ces auto-assemblages des copolymères possèdent des tailles variables (40 nm à 800 nm) avec une membrane en bicouche. Leur caractérisation a été réalisée en phase aqueuse et organique par différentes techniques : DLS, NTA, microscopie biphotonique et AFM. Puis des techniques de caractérisation ont été mises au point pour évaluer une formulation filmogène à base de nitrocellulose contenant de l’urée libre ou encapsulée dans des polymersomes. Cette formulation a été suivie au cours d’essais de stabilité à 25°C et à 40°C pendant 6 mois. Il a été observé une chute de viscosité, surtout à 40°C, attribuée à une coupure des chaînes macromoléculaires de la nitrocellulose (par CES). Les films formés ont un module de Young stable dans le temps avec apparition d’un jaunissement (paramètre b en colorimétrie). La quantité d’urée reste stable dans le temps mais elle accélère les phénomènes de vieillissement. Le jaunissement est dû à la décomposition de l’huile de ricin. L’encapsulation de l’urée au sein des polymersomes n’a pas amélioré la stabilité de la formulation prouvant ainsi le rôle catalyseur de l’urée
This work aims at a better understanding of film-forming formulations developed by Laboratoires Urgo. Two parts have been developed. First, an encapsulation system to protect a model drug in film forming solutions was investigated. Polymersomes in aqueous and organic media have been developed based on amphiphilic copolymers m-PEG-PCL which were synthesized and characterized in the laboratory. Auto-assemblies of copolymers display variable sizes (40 nm to 800 nm) with a bilayer membrane. Their characterization was carried out in aqueous and organic phase by various techniques: DLS, NTA, bi-photonic microscopy and AFM. In a second part, characterization techniques have been developed to assess a film forming solution based on nitrocellulose, containing free or encapsulated urea in polymersomes. This formulation was investigated during stability studies at 25°C and 40°C up to 6 months. A drop in viscosity was observed, especially at 40°C, due to cleavage of the macromolecular chains of nitrocellulose (SEC). The formed films have a stable Young's modulus over time with an appearance of yellowing (parameter b in colorimetry). The urea quantity remains stable in time, but accelerates the aging of the solution. Yellowing is caused by the decomposition of castor oil. The encapsulation of the urea within polymersomes did not improve the stability of the formulation thus proving the catalytic role of urea

It was observed in the ‘80s that the radiation damage on biological systems strongly depends on processes occurring at the microscopic level, involving the elementary constituents of biological cells. Since then, lot of attention has been paid to study elementary processes of photo- and ion-chemistry of isolated organic molecule of biological interest. This work fits in this framework and aims to study the radiation damage mechanisms induced by different types of radiations on simple halogenated biomolecules used as radiosensitizers in radiotherapy. The research is focused on the photofragmentation of halogenated pyrimidine molecules (5Br-pyrimidine, 2Br-pyrimidine and 2Cl-pyrimidine) in the VUV range and on the 12C4+ ion-impact fragmentation of the 5Br-uracil and its homogeneous and hydrated clusters. Although halogen substituted pyrimidines have similar structure to the pyrimidine molecule, their photodissociation dynamics is quite different. These targets have been chosen with the purpose of investigating the effect of the specific halogen atom and site of halogenation on the fragmentation dynamics. Theoretical and experimental studies have highlighted that the site of halogenation and the type of halogen atom, lead either to the preferential breaking of the pyrimidinic ring or to the release of halogen/hydrogen radicals. The two processes can subsequently trigger different mechanisms of biological damage. To understand the effect of the environment on the fragmentation dynamic of the single molecule, the ion-induced fragmentation of homogenous and hydrated clusters of 5Br-uracil have been studied and compared to similar studies on the isolated molecule. The results show that the “protective effect” of the environment on the single molecule hold in the homogeneous clusters, but not in the hydrated clusters, where several hydrated fragments have been observed. This indicates that the presence of water molecules can inhibit some fragmentation channels and promote the keto-enol tautomerization, which is very important in the mutagenesis of the DNA.

We have carried out a series of ab initio R-matrix calculations at the static exchange and close-coupling levels of approximation on molecules of astrophysical interest. These include the polar triatomics HCN and HNC (hydrogen isocyanide) and their isotopologues DCN and DNC, the diatomics CS (carbon monosulphide) and SiO (silicon monoxide), the weakly polar CO molecule and the non-polar CH4 molecule. With the exception of CO, all the calculations presented here were carried out using the software ‘Quantemol-N’ which provides an intuitive user-friendly interface to the UK polyatomic R-matrix codes. A chapter is devoted to the discussion on the software: how to prepare an R-matrix calculation using it, its present capabilities and future development. The ultimate aim of this thesis is to demonstrate the need to account for electron-induced chemistry in any astrophysical model. We seek to show that in the case of polar molecules, namely, those molecules with large dipole moments, electron collisions are the dominant mechanism of rotational excitation in comets and other astrophysical bodies. Specifically, we will show that electron-impact excitation rate coefficients are several orders of magnitude higher than the corresponding atom-molecule ones. The thesis concludes with a summary of the key findings and opportunities (and where necessary improvements) that may arise from them. All the scattering equations presented here used atomic units.

Variational calculations of rotation-vibration spectra are presented for a range of four- and five-atom molecules of atmospheric and astrophysical importance. Using state-of-the-art electronic structure methods, new nine-dimensional potential energy and dipole moment surfaces are constructed for methyl chloride (CH3Cl), silane (SiH4), and methane (CH4). The respective surfaces are rigorously evaluated against high-resolution spectroscopic data from a variety of experimental sources. The ab initio potential energy surfaces represent some of the most accurate to date, whilst intensity simulations utilizing the dipole moment surfaces show good agreement with experiment. A novel application of rotation-vibration computations is introduced to investigate the sensitivity of spectral lines to a possible space-time variation of the proton-to-electron mass ratio μ. The approach relies on finding the mass dependence of the computed energy levels and is only possible because of the remarkable accuracy of variational calculations. Highly sensitive transitions are uncovered for ammonia (NH3) and the hydronium cation (H3O+) which could lead to a tighter constraint on a varying μ. An advantage of the variational approach is that Einstein A coefficients can be determined to help guide future laboratory and astronomical observations. This thesis demonstrates the current capabilities of variational calculations of rotation-vibration spectra and highlights the challenges faced by the field.

Within this work, three physicochemical methods for the hydrophobization of initially hydrophilic solid particles are investigated. The modified particles are then used for the stabilization of oil-in-water (o/w) emulsions. For all introduced methods electrostatic interactions between strongly or weakly charged groups in the system are es-sential. (i) Short chain alkylammonium bromides (C4 – C12) adsorb on oppositely charged solid particles. Macroscopic contact angle measurements of water droplets under air and hexane on flat silica surfaces in dependency of the surface charge density and alkylchain-length allow the calculation of the surface energy and give insights into the emulsification properties of solid particles modified with alkyltrimethylammonium bromides. The measure-ments show an increase of the contact angle with increasing surface charge density, due to the enhanced adsorp-tion of the oppositely charged alkylammonium bromides. Contact angles are higher for longer alkylchain lengths. The surface energy calculations show that in particular the surface-hexane or surface-air interfacial en-ergy is being lowered upon alkylammonium adsorption, while a significant increase of the surface-water interfa-cial energy occurs only at long alkyl chain lengths and high surface charge densities. (ii) The thickness and the charge density of an adsorbed weak polyelectrolyte layer (e.g. PMAA, PAH) influence the wettability of nanoparticles (e.g. alumina, silica, see Scheme 1(b)). Furthermore, the isoelectric point and the pH range of colloidal stability of particle-polyelectrolyte composites depend on the thickness of the weak polye-lectrolyte layer. Silica nanoparticles with adsorbed PAH and alumina nanoparticles with adsorbed PMAA be-come interfacially active and thus able to stabilize o/w emulsions when the degree of dissociation of the polye-lectrolyte layer is below 80 %. The average droplet size after emulsification of dodecane in water depends on the thickness and the degree of dissociation of the adsorbed PE-layer. The visualization of the particle-stabilized o/w emulsions by cryogenic SEM shows that for colloidally stable alumina-PMAA composites the oil-water interface is covered with a closely packed monolayer of particles, while for the colloidally unstable case closely packed aggregated particles deposit on the interface. (iii) By emulsifying a mixture of the corrosion inhibitor 8-hydroxyquinoline (8-HQ) and styrene with silica nanoparticles a highly stable o/w emulsion can be obtained in a narrow pH window. The amphoteric character of 8-HQ enables a pH dependent electrostatic interaction with silica nanoparticles, which can render them interfa-cially active. Depending on the concentration and the degree of dissociation of 8-HQ the adsorption onto silica results from electrostatic or aromatic interactions between 8-HQ and the particle-surface. At intermediate amounts of adsorbed 8-HQ the oil wettability of the particles becomes sufficient for stabilizing o/w emulsions. Cryogenic SEM visualization shows that the particles arrange then in a closely packed shell consisting of partly of aggregated domains on the droplet interface. For further increasing amounts of adsorbed 8-HQ the oil wet-tability is reduced again and the particles ability to stabilize emulsions decreases. By the addition of hexadecane to the oil phase the size of the droplets can be reduced down to 200 nm by in-creasing the silica mass fraction. Subsequent polymerization produces corrosion inhibitor filled (20 wt-%) poly-styrene-silica composite particles. The measurement of the release of 8-hydroxyquinoline shows a rapid increase of 8-hydroxyquinoline in a stirred aqueous solution indicating the release of the total content in less than 5 min-utes. The method is extended for the encapsulation of other organic corrosion inhibitors. The silica-polymer-inhibitor composite particles are then dispersed in a water based alkyd emulsion, and the dispersion is used to coat flat aluminium substrates. After drying and cross-linking the polmer-film Confocal Laser Scanning Micros-copy is employed revealing a homogeneous distribution of the particles in the film. Electrochemical Impedance Spectroscopy in aqueous electrolyte solutions shows that films with aggregated particle domains degrade with time and don’t provide long-term corrosion protection of the substrate. However, films with highly dispersed particles have high barrier properties for corrosive species. The comparison of films containing silica-polystyrene composite particles with and without 8-hydroxyquinoline shows higher electrochemical impedances when the inhibitor is present in the film. By applying the Scanning Vibrating Electrode Technique the localized corrosion rate in the fractured area of scratched polymer films containing the silica-polymer-inhibitor composite particles is studied. Electrochemical corrosion cannot be suppressed but the rate is lowered when inhibitor filled composite particles are present in the film. By depositing six polyelectrolyte layers on particle stabilized emulsion droplets their surface morphology changes significantly as shown by SEM visualization. When the oil wettability of the outer polyelectrolyte layer increases, the polyelectrolyte coated droplets can act as emulsion stabilizers themselves by attaching onto bigger oil droplets in a closely packed arrangement. In the presence of 3 mM LaCl3 8-HQ hydrophobized silica particles aggregate strongly on the oil-water inter-face. The application of an ultrasonic field can remove two dimensional shell-compartments from the droplet surface, which are then found in the aqueous bulk phase. Their size ranges up to 1/4th of the spherical particle shell.
Im Rahmen dieser Arbeit wurden drei Oberflächenmodifikationen zur Hydrophobierung von ursprünglich hydrophilen Feststoffpartikeln entwickelt. Die so modifizierten Partikel werden dann zur Stabilisierung von Öl-in-Wasser Emulsionen verwendet. Für sämtliche entwickelte Methoden sind elektrostatische Wechselwirkungen zwischen stark oder schwach dissoziierten chemischen Gruppen essentiell. (i) Kurzkettige Alkyltrimethylammonium Bromide (C4-C12) adsorbieren auf entgegengesetzt geladenen Partikeln. Makroskopische Kontaktwinkelmessungen von Wasser Tropfen in Luft und Hexan auf flachen Siliziumoxid Oberflächen mit variabler Oberflächenladungsdichte und Alkylkettenlänge ermöglichen die Berechnung der Oberflächenenergie und geben Einblicke in die Emulgationseigenschaften von so modifizierten Feststoffpartikeln. Die Messungen zeigen einen Anstieg des Kontakwinkels mit steigender Oberflächenladungsdichte, bedingt durch die verstärkte Adsorption von entgegengesetzt geladenen Alkyltrimethylammonium Bromiden. Die Kontaktwinkel sind zudem größer für längerkettige Alkyltrimethylammonium Bromide. Die Berechnungen der Oberflächenenergie zeigen, dass besonders die Feststoff-Hexan oder Feststoff-Luft Grenzflächenenergie durch die Adsorption verringert wird, wohingegen die Feststoff-Wasser Oberflächenenergie nur bei längeren Alkylkettenlängen und hohen Oberflächenladungsdichten signifikant ansteigt. (ii) Die Schichtdicke und Ladungsdichte von adsorbierten schwachen Polyelektrolyten (z.B. PMAA, PAH) beeinflusst die Benetzbarkeit von Nanopartikeln (z.B. Aluminiumoxid, Siliziumoxid). Der isoelektrische Punkt und der pH Bereich für kolloidale Stabilität solcher Polyelektrolyt modifizierter Partikel hängt von der Dicke der Polyelektrolytschicht ab. Siliziumoxid und Aluminiumoxid Nanopartikel mit adsorbierten PAH bzw. PMAA werden Grenzflächenaktiv und dadurch befähigt Öl-in-Wasser Emulsionen zu stabilisieren, wenn der Dissoziationsgrad der Polyelektrolytschicht geringer als 80 % ist. Die durchschnittliche Tropfengröße von Dodecan-in-Wasser Emulsionen ist abhängig von der Polyelektrolytschichtdicke und dem Dissoziationsgrad. Die Visualisierung von Partikel stabilisierten Öl-in-Wasser Emulsionen durch kryogene REM zeigt, dass im Falle von kolloidal stabilen Aluminiumoxid-PMAA Partikeln die Öl-Tröpfchen mit einer dichtgepackten Partikelhülle belegt sind, während für kolloidal destabilisierte Partikel eine Hülle aus aggregierten Partikeln gefunden wird. (iii) Durch das Emulgieren einer Lösung des Korrosionsinhibitors 8-Hydroxychinolins (8HQ) in Styrol mit Siliziumoxid Nanopartikeln können stabile Öl-in-Wasser Emulsionen in einem pH Fenster von 4 - 6 hergestellt werden. Der amphoterische Charakter von 8HQ ermöglicht eine pH abhängige elektrostatische Wechselwirkung mit den Siliziumdioxid Nanopartikeln, welche diese Grenzflächenaktiv werden lässt. In Abhängigkeit der Konzentration und des Dissoziationsgrads von 8HQ folgt die Adsorption auf Siliziumdioxid aus elektrostatischen oder aromatischen Wechselwirkungen zwischen 8HQ und der Partikeloberfläche. Bei mittleren adsorbierten Mengen wird die Öl Benetzbarkeit der Partikel ausreichend erhöht um Öl-in-Wasser Emulsionen zu stabilisieren. Kryogene REM zeigt, dass die Partikel dann in dicht gepackte Hüllen, mit teilweise aggregierten Domänen auf der Öltröpfchenoberfläche vorliegen. Durch weiter ansteigende adsorbierte 8HQ Mengen wird die Öl-Benetzbarkeit wieder zurückgesetzt und die Emulgationsfähigkeit der Partikel aufgehoben. Durch die Zugabe von Hexadecan zur Öl Phase kann die Tropfengröße durch Erhöhung des Siliziumdioxid Anteils auf 200 nm herabgesetzt werden. Anschließende Polymerisation des Styrols generiert Korrosionsinhibitor gefüllte (20 Gew-%) Polystyrol-Silizumoxid Komposite. Die Messung der Freisetzungsrate von 8HQ zeigt einen schnellen Anstieg der 8HQ Konzentration in einer gerührten wässrigen Lösung innerhalb von 5 Minuten. Die Verkapselungsmethode wird auch für andere organische Korrosionsinhibitoren erweitert. Die Komposite werden dann in einer wasserbasierten Alkydpräpolymeremulsion dispergiert und diese Mischung wird zur Beschichtung von flachen Aluminiumplatten genutzt. Nach Trocknung und Quervernetzung des Films wird Konfokale Laser Mikroskopie dazu verwendet um die räumliche Verteilung der Composite im Film zu visualisieren. Elektrochemische Impedanzspektroskopie zeigt, dass die Barriereeigenschaften des Films durch die Anwesenheit der Komposite verbessert sind. Raster Vibrationselektroden Messungen zeigen, dass die Korrosionsrate in einem Kratzer des Films durch die Anwesenheit der Inhibitor efüllten Komposite reduziert ist. Durch die Ablagerung von 6 Polyelektroytschichten auf Feststoffstabilisierten Emulsionströpfchen verändert sich deren Oberflächenmorphologie deutlich (gezeigt durch REM). Wenn die Ölbenetzbarkeit der äußeren Polyelektrolytschicht ansteigt, dann können solche Polyelektolytbeschichteten Feststoffstabilisierte Emulsionströpfchen selber als Emulsionsstabilisatoren verwendet werden. Diese lagern sich dann in einer dicht gepackten Schicht auf der Oberfläche von größeren Emulsionstropfen ab. In der Gegenwart von 3 mM LaCl3 aggregieren 8HQ modifizierte Siliziumoxid Partikel stark auf der Öl-Wasser Grenzfläche. Der Einsatz von Ultraschall kann aggregierte Schalenbestandteile von der Tropfenoberfläche wegreißen. Diese Wracks können bis zu einem Viertel der Kugelhülle ausmachen und liegen dann als kolloidale Schalen im Wasser vor.

The template synthesis of core / shell particles is described. One template employed as the core is a gold particle. Polymers employed as the shell are polypyrrole, poly(N-methylpyrrole), and poly(3-methylthiophene). The gold core of the composite particle is removed to yield a hollow polymer capsule, the core dimensions of which are determined by the dimensions of the template. Shell thickness is also controlled easily. Permeability of the shell is varied according to shell composition, oxidation state of the polymer, and incorporated counterion. Attaching rhodamine B, anthraquinone, or horseradish peroxidase to the gold particle template prior to shell formation and removal of the core results in encapsulation of the molecule. A second template employed as the core is a micelle. Micelle core / polymer shell particles may possibly be further utlilized as an encapsulation method by solubilizing a molecule in the core of the micelle prior to polymer shell formation.

Here the ab-initio R-Matrix method has been used to carry out electron-molecule collision calculations on the the molecules of interstellar interest C3N, C2H & CN, and molecules found in industrial plasma applications SiBr, SiBr2 and NaI. These were carried out using the UK Molecular R-Matrix codes, along with the Quantemol expert system for running these codes. Calculations have also been carried out on electron collisions with atomic oxygen using these codes, with details included about the problems faced in running an atomic calculation with the molecular codes. Calculations on each species include comparison of different models, including staticexchange and close-coupling models (with different size CAS tried), various basis sets, and for some species different initial orbitals. These different initial orbitals were either taken from the codes themselves (for SCF orbitals), or the quantum chemistry program MOLPRO (for natural orbitals), for the latter numerous state averaged orbitals were tried with different weightings in order to produce good target energies for carrying into the scattering calculation. Results for all calculations include scattering observables such as eigenphase sums, elastic and excitation cross-sections, bound anionic states and resonance positions and widths. Also a new theory has been developed for calculating rotational cross-sections which includes the spin angular momentum of the incoming scattering electron, this has been implemented into the already existing code ROTLIN, which can calculate rotational cross-sections using the scattering data from an R-Matrix calculation.

This thesis has developed an innovative technology, electrospraying, that allows biodegradable microparticles to deliver pharmaceuticals that aid bone regeneration. The establishment, characterisation and optimisation of the technique are a step forward in developing an affordable and safe alternative to the products used currently in the clinical setting for the treatment of musculoskeletal disorders. The researcher has also investigated electrospraying as a coating technique on biodegradable structures that are used to replace damaged tissues, in order to provide localised and efficient drug delivery in the site of the defect to help tissue reconstruction.

Una de les àrees més prometedores en recerca biomèdica i farmacèutica és el disseny molecular computacional, que intenta establir relacions entre propietats físico-químiques i activitat biològica.
L'èxit d'aquestes tècniques depen críticament de la qualitat de la descripció molecular. En aquest sentit, metodologies basades en potencials d'interacció molecular (MIP) són eines útils per la comparació de compostos que presenten comportaments biològics semblants.
Aquest projecte desenvolupa eines per comparar molècules basades en la caracterització de llurs MIPs. El programa de similaritat molecular MIPsim ha estat desenvolupat i aplicat a diferents problemes biològics.
Aquesta tesi consisteix en quatre estudis científics que mostren l'ús del MIPSim en aliniament molecular, catalisi enzimàtica, en acoratge de molècules dins el lligand i en estudis 3D-QSAR.
One of the most promising areas in biomedical and pharmaceutical research is computer assisted molecular design, which tries to stablish relationships between physicochemical properties and biological activity.
The success of these techniques depends critically on the quality of the molecular description. In this sense, methodologies based on molecular interaction potentials (MIP) are useful tools for the comparison of compounds displaying related biological behaviours.
This project aims to develop tools to compare 'molecules based on the characterization 'of their MIPs. To this end, the molecular similarity program MIPSim has been further developed and applied to different biological problems.
This thesis consists on four scientific studies showing the use of MIPSim for molecular alignment, enzymatic catalysis, ligand-protein docking and 3D-QSAR analyses.

Les composés organiques volatils biogéniques (COVBs), et en particulier les monoterpènes (C10H16), sont des molécules naturellement présentes dans l’atmosphère, qui sont liées à la formation d’aérosols organiques secondaires (SOA). Ils peuvent altérer les propriétés physiques et chimiques de l’atmosphère, avoir des effets négatifs sur la santé humaine et contribuer aux changements climatiques. Une forte relation existe entre la structure d’un système moléculaire et les interactions inter- et intramoléculaires présentes à l’échelle moléculaire. Par conséquent, l’accès aux informations sur la structure, en phase gazeuse, et la dynamique interne pourrait être essentiel pour prédire les voies possibles de réaction ou de la formation de complexes et d’agrégats.La spectroscopie micro-ondes à transformée de Fourier (FTMW) une fois combinée aux calculs de chimie quantique, sont une approche fiable pour étudier le paysage conformationnel, la structure et la dynamique interne de plusieurs types des molécules, et notamment les molécules d’intérêt atmosphérique, leurs produits d’oxydation et leurs complexes associés.Dans le cadre de cette thèse, nous avons appliqué cette approche théorique-expérimentale pour caractériser les complexes de deux monoterpénoïdes : le fenchol (C10H18O) et la fenchone (C10H16O) avec un autre contaminant atmosphérique, à savoir le H2S. Les conformations stables en phase gazeuse ont été identifiées dans le spectre de rotation pure à l’aide des calculs ab initio et DFT. Une analyse comparative des complexes observés avec leurs analogues hydratés a confirmé la présence d’une liaison hydrogène plus faible. En plus, nous avons observé un mouvement de grande amplitude, décrit qualitativement. Les interactions non covalentes stabilisantes des deux complexes ont également été évaluées.De manière similaire, et dans le même contexte général, nous avons également caractérisé le paysage conformationnel et la rotation interne du groupe méthyle dans le cas de la limona cétone (C9H14O), qui est un BVOC issu de l’oxydation du limonène. La hauteur de barrière expérimentale de la torsion du méthyle a montré un certain écart par rapport aux valeurs calculées, ce qui nous a poussé vers une investigation plus approfondie, qui a révélé la présence d’une interaction intermoléculaire.La deuxième partie de cette thèse a été consacrée à la construction et à l’évaluation d’un nouveau spectromètre FTMW à dérive de fréquence, large bande (6-18 GHz). Une description technique détaillée du spectromètre est donnée dans ce manuscrit. De plus, les tests préliminaires effectués pour évaluer les performances du spectromètre sont rapportés
Biogenic volatile organic compounds (BVOCs), and especially monoterpenes (C10H16), are molecules naturally occurring in the atmosphere, which have been linked to the formation of secondary organic aerosol (SOA). They can alter the physical and chemical properties in the atmosphere, have negative effects on human health and contribute to climate change. There exists a strong relationship between the structure of a molecular system and the inter- and intramolecular interactions present on the molecular scale.Hence, having in-depth information about the gas phase structure and internal dynamics of these molecules, or their molecular complexes, is important to better understand their reaction pathways and complexation patterns.The synergic combination of quantum chemical calculations and Fourier transform microwave (FTMW) spectroscopy has been shown to be a reliable approach to examine the conformational landscape, structure and internal dynamics of several types of molecules of atmospheric interest, their oxidation products and their complexes. In the framework of this thesis, we have applied this theoretical-experimental approach to characterize the complexes of two monoterpenoids: fenchol (C10H18O) and fenchone (C10H16O) with another atmospheric contaminant: the H2S molecule. The gas phase stable conformations were identified in the pure rotational spectrum with the supportof ab initio and DFT calculations. A comparative analysis of the observed complexes with their water analogues confirmed the presence of weaker hydrogen bonds. On top of that, we observed a large amplitude motion, that was qualitatively described. The stabilizing non-covalent interactions of the two complexes were also evaluated.In a similar manner, and within the same general context, we also characterized the conformational landscape and methyl internal rotation in the case of limona ketone (C9H14O), which is a biogenic volatile organic compounds (BVOC) originating from the oxidation limonene. The experimental barrier height of the methyl torsion showed some deviation from the calculated values, which pushed toward a more thorough examination, that revealed the presence of an intermolecular interaction.The second part of this thesis was dedicated to the construction and evaluation of a broadband chirped pulse FTMW spectrometer, operating in the range 6-18 GHz. A detailed technical description of the spectrometer is given herein. Moreover, the preliminary tests performed to evaluate the performance of the spectrometer are reported

The spectroscopic investigation of the gas-phase molecules relevant for the chemistry of the atmosphere and of the interstellar medium has been performed. Two types of molecules have been studied, linear and symmetric top. Several experimental high-resolution techniques have been adopted, exploiting the spectrometers available in Bologna, Venezia, Brussels and Wuppertal: Fourier-Transform-Infrared Spectroscopy, Cavity-Ring-Down Spectroscopy, Cavity-Enhanced-Absorption Spectroscopy, Tunable-Diode-Laser Spectroscopy. Concerning linear molecules, the spectra of a number of isotopologues of acetylene, 12C2D2, H12C13CD, H13C12CD, 13C12CD2, of DCCF and monodeuterodiacetylene DC4H, have been studied, from 320 to 6800 cm-1. This interval covers bending, stretching, overtone and combination bands, the focus on specific ranges depending on the molecule. In particular, the analysis of the bending modes has been performed for 12C2D2 (450-2200 cm-1), 13C12CD2 (450-1700 cm-1), DCCF (320-850cm-1) and DC4H (450-1100 cm-1), of the stretching-bending system for 12C2D2 (450-5500 cm-1) and of the 2nu1 and combination bands up to four quanta of excitation for H12C13CD, H13C12CD and 13C12CD2 (6130-6800 cm-1). In case of symmetric top molecules, CH3CCH has been investigated in the 2nu1 region (6200-6700 cm-1), which is particularly congested due to the huge network of states affected by Coriolis and anharmonic interactions. The bending fundamentals of 15ND3 (450-2700 cm-1) have been studied for the first time, characterizing completely the bending states, v2 = 1 and v4 = 1, whereas the analysis of the stretching modes, which evidenced the presence of several perturbations, has been started. Finally, the fundamental band nu4 of CF3Br in the 1190-1220 cm-1 region has been investigated. Transitions belonging to the CF379Br and CF381Br molecules have been identified since the spectra were recorded using a sample containing the two isotopologues in natural abundance. This allowed the characterization of the v4 = 1 state for both isotopologues and the evaluation of the bromine isotopic splitting.

[ES] La presente tesis doctoral titulada "New nanostructured suports with signal amplification features for the detection of molecules and biomolecules of interest" se centra en el diseño y preparación de nuevos materiales híbridos orgánicos-inorgánicos constituidos por puertas moleculares soportadas sobre alúmina mesoporosa con el objetivo de desarrollar nuevos sistemas sensores con aplicaciones potenciales en el campo de la diagnosis y del control alimentario. En el primer capítulo de la tesis se introducen los conceptos en los que están basados los estudios realizados y los materiales preparados. A continuación, en el segundo capítulo se describen los objetivos generales de la tesis que serán abordados en los siguientes apartados. En el tercer capítulo se presenta el diseño y optimización de un nanodispositivo para la detección de la bacteria Mycoplasma fermentans. En primer lugar, los poros de una placa de alúmina mesoporosa se cargan con un indicador fluorescente (rodamina B). Seguidamente, la superficie es funcionalizada con una secuencia de ADN complementaria a una región altamente conservada de la subunidad ribosomal 16S de la bacteria Mycoplasma fermentans. El impedimento estérico generado por las secuencias de ADN ancladas al exterior de los poros impide la salida del indicador encapsulado. Únicamente en presencia de DNA de la bacteria Mycoplasma fermentans, se produce la apertura de los poros permitiéndose la difusión de la carga (rodamina B) que es posteriormente medida mediante espectroscopía de fluorescencia. En el capítulo cuatro se diseña de un nanodispositivo capaz de detectar de forma rápida, sensible y selectiva la bacteria Staphylococcus aureus. Para la preparación del material sensor, un soporte de alúmina mesoporosa es, en primer lugar, cargado con el indicador fluorescente rodamina B. A continuación, los poros del soporte son tapados mediante el anclaje de un aptámero que reconoce de forma específica la bacteria. Solamente en presencia de Staphylococcus aureus se produce la liberación del indicador encapsulado, que es posteriormente medido mediante espectroscopía de fluorescencia. Además, la respuesta obtenida es específica para Staphylococcus aureus. Este sistema ha sido ensayado en muestras reales. En el sexto capítulo, diseña un nanodispositivo híbrido orgánico-inorgánico consistente en un material de alúmina mesoporosa cubierto con una secuencia de ADN específica para la detección de ADN del hongo Pneumocystis jirovecii. En este caso, el soporte de alúmina cargado con rodamina B se recubre con una secuencia de ADN específica para el reconocimiento de este hongo. En presencia del organismo, la horquilla hibrida con el ADN del hongo, lo que resulta en una conformación triplex con elevada afinidad y estabilidad que induce, al mismo tiempo, el desplazamiento de este complejo de la superficie. Como consecuencia de este reconocimiento la carga se libera y es cuantificada mediante espectroscopía de fluorescencia. El sistema ha sido satisfactoriamente validado. En el séptimo capítulo, se diseña un sistema sensor con la capacidad de detectar gluten de forma rápida y sencilla en extractos de alimentos procesados y no procesados. Para ello, un soporte de alúmina mesoporosa se carga con rodamina B y los poros se recubren con un aptámero específicamente diseñado para la detección de la proteína gliadina, que constituye el 50 % del total del clúster de elementos que forman el gluten. La elevada afinidad y especificidad entre el aptámero y la proteína en cuestión hacen que en presencia de ésta se produzca un desplazamiento de la puerta molecular que permite la difusión del colorante encapsulado que es finalmente monitorizado mediante espectroscopía de fluorescencia. Finalmente, en el capítulo octavo se discuten de forma conjunta los resultados obtenidos en los capítulos anteriores y la potencial aplicación de los sistemas desarrollados en el actual sistem
[CA] La present tesi doctoral, titulada "New nanostructured supports with signal amplification features for the detection of molecules and biomolecules of interest", es centra en el disseny i preparació de nous materials híbrids orgànics-inorgànics constituïts per portes moleculars suportades sobre alúmina mesoporosa amb l'objectiu de desenvolupar nous sistemes sensors amb potencials aplicacions en el camp de la diagnosi i del control alimentari. En el primer capítol de la tesi s'introdueixen els conceptes en què estan basats els estudis realitzats i els materials preparats. A continuació, en el segon capítol es descriuen els objectius generals de la tesi que seran abordats en els següents apartats. En el tercer capítol es presenta el disseny i optimització d'un nanodispositiu per a la detecció de la bactèria Mycoplasma fermentans. Primerament, els porus d'una placa d'alúmina mesoporosa són carregats amb un indicador fluorescent (rodamina B). Seguidament, la superfície és funcionalitzada amb una seqüència d'ADN complementaria a una regió altament conservada de la subunitat ribosomal 16S de la bactèria Mycoplasma fermentans. L'impediment estèric generat per les seqüències d'ADN ancorades a l'exterior dels porus impedeix l'alliberament de l'indicador encapsulat. Únicament en presencia d'ADN de la bactèria Mycoplasma fermentans, es produeix l'obertura dels porus permetent la difusió de la càrrega (rodamina B) que és posteriorment mesurada mitjançant fluorescència. En el capítol quatre es dissenya un nanodispositiu capaç de detectar de forma ràpida, sensible i selectiva la bactèria Staphylococcus aureus. Per a la preparació del material sensor, el suport d'alúmina mesoporosa és, primerament, carregat amb l'indicador fluorescent rodamina B. A continuació, els porus del suport són tapats mitjançant l'ancoratge d'un aptàmer que reconeix de forma específica a la bactèria. Solament en presència de Staphylococcus aureus es produeix l'alliberament de l'indicador encapsulat, que és posteriorment mesurat mitjançant espectroscòpia de fluorescència. A més a més, la resposta obtinguda és específica per Staphylococcus aureus. Aquest sistema ha sigut validat amb mostres reals de pacients. En el sisè capítol, es dissenya un nanodispositiu híbrid orgànic-inorgànic consistent en un material d'alúmina mesoporosa cobert amb una seqüència d'ADN específica per a la detecció de l'ADN del fong Pneumocystis jirovecii. En aquest cas, el suport d'alúmina carregat amb l'indicador fluorescent rodamina B és recobert amb una seqüència d'ADN específica per al reconeixement d'aquest fong. En presència de l'organisme, la forquilla hibrida amb l'ADN del fong, resultant en una conformació triplex amb elevada afinitat i estabilitat, que indueix, al mateix temps, el desplaçament d'aquest complex de la superfície. Com a conseqüència d'aquest reconeixement la càrrega és alliberada i quantificada mitjançant espectroscòpia de fluorescència. El sistema ha sigut validat com a mètode diagnòstic mitjançant l'anàlisi de mostres reals de pacients. En el seté capítol, es dissenya un sistema sensor amb la capacitat de detectar gluten de forma ràpida i senzilla en extractes d'aliments processats i no processats. Per a això, un suport d'alúmina mesoporosa es carrega amb indicador fluorescent rodamina B i posteriorment és recobert amb un aptàmer específicament dissenyat per a la detecció de la proteïna gliadina, que constitueix el 50 % del total del clúster d'elements que formen el gluten. L'elevada afinitat i especificitat entre l'aptàmer i la proteïna en qüestió fa que en presència d'aquesta es produesca un desplaçament de la porta molecular que permet la difusió de la càrrega encapsulada i que serà finalment monitoritzada mitjançant espectroscòpia de fluorescència. Finalment, en el capítol vuité es discuteixen de manera conjunta els result
[EN] The PhD thesis hereby presented and entitled "New nanostructured supports with signal amplification features for the detection of molecules and biomolecules of interest", focuses in the design and preparation of new hybrid organic-inorganic materials constituted by molecular gates supported over mesoporous alumina with the aim of developing new sensor probes of potential applications in the fields of diagnosis and food control. In the first chapter, the concepts in which studies and prepared materials are based, are introduced. Next, the second chapter describes the general objectives of this thesis, which will be approached in the following sections. In the third chapter, it is presented in detail the design and optimization process of a nanodevice applied for the detection of Mycoplasma fermentans bacterium. First of all, mesoporous alumina porous films are charged with a fluorescent indicator (rhodamine B). Then, the surface is functionalized with a DNA sequence complementary to a highly conserved region of the 16S ribosomal subunit of the bacterium Mycoplasma fermentans. Steric hindrance generated by DNA sequences on the surface inhibits the release of the encapsulated indicator. Only in the presence of bacterium Mycoplasma fermentans DNA, molecular gates open, allowing payload diffusion to the solution, which is measured by fluorescence spectroscopy. In chapter four, it is carried out the design and optimization of a nanodevice able to detect Staphylococcus aureus bacterium in a fast, sensitive and selective way. For the sensor preparation, alumina mesoporous support is, first, loaded with the rhodamine B fluorescent dye. Then, the mesoporous are blocked through the attachment of an aptamer that recognises specifically this bacterium. Exclusively in the presence of Staphylococcus aureus it is accomplished the release of the encapsulated dye, which is later monitored by fluorescence spectroscopy. The response obtained is specific for Staphylococcus aureus. This system has been validated in real samples. In the sixth chapter, it is detailed the design and optimization process of a hybrid organic-inorganic nanodevice based on a capped mesoporous alumina material for the detection of Pneumocystis jirovecii fungus DNA. In this case, the mesoporous alumina support is loaded with a fluorescent dye and decorated with a specific oligonucleotide sequence designed for the recognition of Pneumocystis fungus. In the presence of the target organism, the fork-like oligonucleotide hybridises with the DNA of the fungus, which results in the adoption of a triplex conformation with high affinity and stability that induces, at the same time, the displacement of this complex from the surface. Consequently, the payload diffused to the solution is quantified through fluorescence spectroscopy. The system has been successfully validated. In the seventh chapter, it was developed a sensor system for gluten detection, in a quick and easy way, in processed and non-processed food extracts. For this, a mesoporous alumina support is loaded with the fluorescent dye rhodamine B, and later was functionalized with an aptamer specifically designed for the detection of gliadin, a protein that constitutes 50 % of average cluster elements that forms gluten. The protein-aptamer high affinity and specificity induce the displacement of the capping aptamer and cargo delivery, which is monitored through fluorescence spectroscopy. Finally, in the eighth chapter, the results obtained in the previous chapters and the potential application of the systems developed as health and food control system are discussed.
We thank the Spanish Government projects MAT2015-64139-C4-1-R, AGL2015-70235-C2-2-R, and TEC2015-71324-R (MINECO/FEDER, UE), the Generalitat Valenciana (project PROMETEOII/2014/047), the Catalan authority (project AGAUR 2014SGR1344), and ICREA under the 2014 ICREA Academia Award for support. This study was supported by the Spanish Government projects RTI2018-100910-B-C41 and SAF2017-82251-R (MCUI/AEI/FEDER, UE), the Generalitat Valenciana (project PROMETEO/2018/024), the Universitat Politècnica de València−Instituto de Investigación Sanitaria La Fe (B02-MIRSA project), CIBER-BBN (NANOPATH and valorization project CANDI-EYE) and co-financed by the EU through the Valencian Community ERDF PO 2014-2020. This research was funded by the Spanish Government, projects RTI2018-100910-B-C41 (MCUI/AEI/FEDER, UE) and CTQ2017-84415-R
Pla Blasco, L. (2021). New nanostructured supports with signal amplification features for the detection of molecules and biomolecules of interest [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/166500
TESIS

Line lists including positions and absolute intensities have been produced using a combination of theoretical and experimental methods, for several spectroscopic systems of diatomic molecules, including the C2 and 12C13C Swan systems, the CN, 13CN, and C15N A2Π-X2Σ+ (red), B2Σ+-X2Σ+ (violet), and X2Σ+ state rovibrational systems, the CP A2Π-X2Σ+ system, and the NH X3Σ− state rovibrational and rotational transitions. Preliminary calculations for the OH X2Π state rovibrational transitions have also been performed. RKR potential energy curves, vibrational wavefunctions, and matrix elements (MEs) were calculated using the programs RKR1 and LEVEL. The MEs were transformed from Hund’s case (b) to (a), for which an equation was derived. Einstein A values were calculated from the case (a) MEs and molecular constants using PGOPHER. These lists will be useful in the fields of astronomy, combustion science, materials science, and anywhere else that transitions of these diatomic molecules are investigated. Line intensities have also been used to retrieve an atmospheric CO2 volume mixing ratio. A new technique for the satellite remote sensing of atmospheric greenhouse gases via absorption of short-wave infrared laser signals transmitted between counter-rotating satellites in low Earth orbit has recently been proposed; this would enable the acquisition of a long-term, stable, global set of altitude-resolved concentration measurements. The first ground-based experimental demonstration of this new infrared-laser occultation method is presented, in which the atmospheric absorption of CO2 near 2.1 µm and CH4 near 2.3 µm were measured over a 144 km path length between two peaks in the Canary Islands, using relatively low power diode lasers. The retrieved CO2 volume mixing ratio of 400 ppm (±15 ppm) is consistent within experimental uncertainty with simultaneously recorded validation measurements. The new method has a sound basis for monitoring atmospheric CO2 and other greenhouse gases.

De nombreux composés bioactifs hydrophobes sont actuellement mis en avant en raison de leurs propriétés nutritionnelles et fonctionnelles. Une attention particulière est, en conséquence, portée à leur incorporation en tant qu'ingrédients dans des aliments fonctionnels. Cependant, la majorité de ces composés bioactifs sont caractérisés par une faible solubilité en milieu aqueux, une dégradation au cours des procédés de transformation ainsi qu'une absorption limitée au niveau du tractus gastro-intestinal. La micelle de caséines, grâce à ses propriétés fonctionnelles uniques, peut être considérée comme un support d’encapsulation naturel pour ces molécules bioactives hydrophobes. En effet, une des originalités de cette suprastructure est sa dynamique dans le lait se caractérisant par des échanges réversibles de protéines et de minéraux entre le sérum et la structure micellaire interne en fonction des conditions physicochimiques, et notamment avec la température. En particulier, un stockage du lait à 4°C permet la dissociation sélective de la caséine β de la phase micellaire vers la phase soluble et un retour à température ambiante permet sa réintégration. L’objectif de cette thèse est de développer une nouvelle stratégie d’encapsulation de molécules bioactives hydrophobes dans les micelles de caséines via cette dynamique de la caséine β. Dans un premier temps, l’optimisation de la dissociation de la caséine β de la micelle de caséines a été réalisée en modifiant la température et le pH, tout en portant une attention particulière au maintien de l’intégrité des micelles déplétées en caséines β. Un procédé de séparation physique de la caséine β solubilisée a été optimisé par microfiltration à l’échelle pilote. Une étude de la concentration micellaire critique de la caséine β a permis de vérifier son état monomérique à l’issue de cette séparation. Une étude de la cinétique d’interaction entre la caséine β monomérique et deux composés bioactifs hydrophobes, la curcumine et la vitamine D3, a ensuite été réalisée par résonance plasmonique de surface et par spectroscopie de fluorescence. La curcumine a été choisie pour la suite de l’étude au vu de sa bonne affinité pour la caséine β. Le complexe caséine β monomérique-curcumine a ensuite été encapsulé dans des micelles de caséines préalablement déplétées en caséines β. Les résultats de ces travaux montrent l’efficacité de cette stratégie d’encapsulation qui peut présenter un intérêt particulier pour la vectorisation de molécules bioactives hydrophobes afin d’assurer leur protection dans des produits laitiers pauvres en matière grasse.De plus, au cours de ce projet, une méthode de caractérisation des propriétés morphologiques et nano-mécaniques des micelles de caséines par microscopie à force atomique en milieu liquide a été développée. Cette méthode représente un outil intéressant de compréhension de la structure micellaire dans son environnement natif et offre la possibilité d’évaluer l’impact de certaines modifications sur les propriétés de la micelle de caséines, comme sa déplétion en caséine β ou sa réticulation
In the last years, the number of studies highlighting the nutritional and functional properties of several hydrophobic bioactives has markedly increased. Special attention is consequently paid to their addition as ingredients to food. However, most of these hydrophobic compounds display a low aqueous solubility, poor stability during processing and low absorption in the gastrointestinal tract. Casein micelles exhibiting unique set of properties can be considered as a natural nanocarrier for these molecules. Actually, changes in environmental factors namely pH and temperature induce the dissociation of caseins and minerals from the colloidal phase to the soluble phase. Particularly, a selective dissociation of β-casein occurs at low temperatures. This effect is reversed with an increase in temperature, with a transfer of β-casein from the serum to the micelles when equilibrated at room temperature. The aim of this study is to develop a novel encapsulation strategy to incorporate hydrophobic bioactive compounds into casein micelles using the β-casein reversible dissociation. First, the β-casein dissociation from casein micelles was optimized by temperature and pH modifications while preserving the integrity of the β-casein depleted casein micelles. The separation of dissociated β-caseins from casein micelles was carried out by microfiltration at a pilot scale. The β-casein critical micelle concentration was concurrently evaluated to ensure the monomeric state of -casein after separation. Secondly, the binding kinetic between monomeric β-casein and two hydrophobic compounds, curcumin and vitamin D3, was investigated by surface plasmon resonance and fluorescence spectroscopy. Curcumin was then selected thanks to its high affinity to -casein β. The complex monomeric β-casein – curcumin was encapsulated in β-casein depleted casein micelles. The results of this study show the efficiency of this encapsulation strategy of hydrophobic bioactive compounds, which could be used to protect such molecules in low fat dairy products.Besides, during this project, a novel strategy was developed in order to evaluate the casein micelle topography and nanomechanical properties by atomic force microscopy in liquid environment. This method opens a new line of investigation to better understand the casein micelle structure in its native environment but also investigate the impact induced by the modification of physico-chemical conditions on its topography and elastic properties

A series of water-soluble platinum(II) terpyridine complexes with functionalized alkynyl ligands and a boronic acid-containing polymer, PAAPBA, have been synthesized and characterized. The photophysical and electrochemical properties of all the platinum(II) complexes have been studied. Some of the complexes have been demonstrated to show ground-state aggregation in organic solvents and aqueous solutions at high concentrations, leading to Pt…Pt and/or π–π interactions and hence the emergence of metal-metal-to-ligand charge transfer (MMLCT) transitions in both the UV−visible and emission spectra. The induced self-assembly of [Pt(tpy)(C≡CC6H4−CH2NMe3-4)](OTf)2 by PAAPBA has been explored for the development of glucose sensing protocols and α-glucosidase assay by monitoring the triplet metal-metal-to-ligand charge transfer (3MMLCT) emission in the near-infrared (NIR) region. [Pt(tpy){C≡CC6H4− {NHC(=NH2+)(NH2)}-4}](OTf)2 has been observed to undergo induced aggregation in the presence of citrate, with good selectivity over other mono- and dicarboxylates in the tricarboxylic acid (TCA) cycle. Enzymatic activity of citrate lyase has also been probed by the emission spectral changes of the complex in the NIR region. A series of water-soluble alkynylplatinum(II) terpyridine complexes and water-soluble conjugated polyelectrolytes (CPEs) have been synthesized and characterized. The UV–vis absorption and emission properties of the platinum(II) complexes and CPEs have been investigated in organic solvents and/or aqueous buffer solutions. The electrochemical properties and ground-state aggregation at high concentrations of the platinum(II) complexes have also been examined. Two-component ensembles containing selected platinum(II) complexes and PPE-SO3− have been studied, and Förster resonance energy transfer (FRET) has been demonstrated from the PPE-SO3− donor to the aggregated complexes as acceptors. The ensemble containing PPE-SO3− and [Pt(tpy)(C≡CC6H4CH2NMe3-4)](OTf)2 has been employed for a “proof-of-principle” label-free detection of human serum albumin (HSA) in pH 3 buffer solutions with high selectivity and sensitivity, while another ensemble containing PPE-SO3− and [Pt{tpy(C6H4CH2NMe3-4)-4’}(C≡CC6H5)](OTf)2 has been utilized for selective label-free detection of G-quadruplex structure of the human telomeric DNA in physiological buffer solutions. A series of water-soluble platinum(II) terpyridine complexes with stimuli-responsive alkynyl ligands and a series of water-soluble platinum(II) metallosupramolecular triblock copolymers have been synthesized and characterized. The photophysical and electrochemical properties as well as the ground-state aggregation of the complexes have been investigated. Some of them have been found to show different electronic absorption and emission properties in aqueous solution at different pHs due to aggregation/deaggregation of the complexes. One of the complexes has been employed for live-cell imaging experiments to locate acidic organelles, such as lysosomes, in MDCK cells. The water-soluble platinum(II) metallosupramolecular triblock copolymers have been found to show an increase in 3MMLCT emission intensity in the red-NIR region with temperature, which has been attributed to the formation of spherical polymeric micelles. The platinum(II) triblock copolymer with pH-responsive –CH2NMe2 moieties has been demonstrated as a NIR-emitting dual sensor for pH and temperature through the changes in hydrophilicity and hence the emission properties with pH and temperature simultaneously.
published_or_final_version
Chemistry
Doctoral
Doctor of Philosophy

Ces dernières décennies, la spectroscopie moléculaire a bénéficié du progrès des spectromètres, notamment en terme de sélectivité et sensibilité, et de méthodes d'analyse et de calculs de chimie quantique toujours plus avancés. Désormais, la spectroscopie rotationnelle s'oriente vers l'analyse de systèmes moléculaires plus complexes caractérisés spectralement par une forte densité de raies. La congestion spectrale des espèces étudiées dans ma thèse s'explique non seulement par de faibles constantes rotationnelles mais aussi par la présence d'états vibrationnels excités à température ambiante, une forte richesse isotopique, un haut degré de splittings dus aux mouvements de grande amplitude ou encore par un paysage conformationnel complexe. Cette thèse illustre ainsi divers scénarii à travers les études du chlorure de thionyle, des nitrotoluènes et des méthoxyphénols. Les spectres rovibrationnels des bandes v2 et v5 des isotopologues du chlorure de thionyle ont été mesurés dans l'infrarouge lointain au synchroton SOLEIL et analysés en utilisant une approche semi-automatique basée sur des algorithmes évolutionnaires. Les isomères du nitrotoluène ont été ciblés pour leur intérêt défense comme traceurs d'explosif (TNT), les spectres de rotation pure ont été mesurés dans les régions micro-ondes en jet moléculaire et millimétrique à température ambiante. Le spectre millimétrique du 3-nitrotoluène était particulièrement faible et congestionné avec des splittings dus à la rotation interne très importants (jusqu'à plusieurs GHz) en raison d'une barrière de rotation très faible ( Vз=6.7659(24)cmˉ ¹). La limite de détection a été estimée et une liste de raies établie. Les spectres millimétriques des 2-nitrotoluène et 4-nitrotoluène ont également été partiellement analysés. Enfin, les méthoxyphénols émis lors de feux de biomasse ont également étudiés comme précurseurs d'aérosols organiques secondaires pour leur détection atmosphérique future. Associée à des calculs de chimie quantique, l'analyse du spectre millimétrique du 3-méthoxyphénol mesuré à température ambiante dans la région millimétrique a permis de déterminer la stabilité relative de quatre conformères
In recent decades, molecular spectroscopy has benefited from the progress of spectrometers, particularly in terms of selectivity and sensitivity, and from the continuous advancement of the analysis methods and quantum chemistry calculations. Today, rational spectroscopy is moving towards the analysis of more complex molecular systems spectrally characterized by a high density of lines. The spectral congestion of the species studied in this thesis is not only explained by low rotational constants, but also by the presence of vibrational states excited at room temperature, a high isotopic richness, a high degree of line splitting due to large amplitude motions or by a complex conformational landscape. This thesis thus illustrates various scenarios through the studies of thionyl chloride, nitrotoluenes and methoxyphenols. The rovibrational spectra of the v2 and v5 bands of the isotopologues of thionyl chloride were measured in far-infrared at the SOLEIL synchroton and analyzed using a semi-automatic approach based on evolutionary algorithms. The isomers of nitrotoluene have been targeted for military application as explosive taggants (TNT), the pure rotation spectra were measured in the microwave region in molecular jet and in the millimeter-wave region at room temperature. The millimeter-wave spectrum of 3-nitrotoluene was especially weak and congested with very large internal rotation splittings (up to several GHz) due to a very weak rotational barrier (V3=6.7659(24)cmˉ ¹). The detection limit was estimated and a linelist established. The 2-nitrotoluene and 4-nitrotoluene millimeter-wave spectra have been also partially analyzed. Finally, methoxyphenols emitted during biomass fires have also been studied as they are secondary organic aerosol precursors for their future atmospheric detection. Combined with quantum chemistry calculations, the analysis of the millimeter-wave spectrum of the 3-methoxyphenol measured at room temperature permitted the relative stability of four conformers to be determined

La fonction barrière de la peau, qui protège l’organisme contre les molécules exogènes, limite la pénétration des actifs cosmétiques, ce qui réduit l’efficacité des molécules actives dans les couches profondes de l’épiderme. Il est alors apparu essentiel d'optimiser l'administration des actifs cosmétiques déjà existants afin d’en tirer tout le bénéfice escompté. Certaines innovations sont développées pour répondre à ce défi, notamment l’encapsulation des actifs cosmétiques dans des nanosystemes. En parallèle, il est nécessaire de s’intéresser aux méthodes analytiques capables de fournir une information qualitative et quantitative sur ces systèmes dispersés dans un produit fini complexe et de permettre une évaluation biologique à différents stades de développement des formulations
The barrier function of the skin, which protects the body against exogenous molecules, limits the penetration of active cosmetic ingredients (ACI), thus reduce the effectiveness of molecules with a deep cellular target. Therefore, it appeared crucial to optimize the administration of existing active cosmetic in order to get the full benefits expected. Some innovations are explored to bypass this issue, including the encapsulation of existing active cosmetic in nanocarriers. In parallel, it is important to also focus on the development of analytical methodologies that could provide qualitative and quantitative information, in particular the determination of ACI contents and potentially excipients incorporated in a final form, and biological evaluation at different stages of formulation

The interaction between metal nanoparticles and small molecules has been investigated by FTIR and UV-visible absorption spectroscopy. Electrospray deposition into an argon matrix was chosen as the initial method. An electrospray metal source was tested in development stage. Both the formation of a stable corona discharge as well as a stable Taylor cone were successfully completed. Problems arose when the entire system was tested. It was determined that the vacuum was insufficient for the length of the flight path. Focus then shifted to nanoparticles in more conventional environments. Sol-gel encapsulated nanoparticles were generated, in the form of both monoliths as well as thin film coatings on silicon wafers. The gels were exposed to 1atm of carbon monoxide in a gas cell. The method encountered problems due to spectral interference from the matrix. The next attempt consisted of solution stabilized nanoparticles. The solution was exposed to various amounts of both ammonium sulphate and diethylamine. There was again the problem of solvent interference, even when attempting to observe the system using Raman spectroscopy. Finally, surface stabilized nanoparticles were generated, using 3-mercaptopropyltrimethoxysilane to adhere the particles to glass slides. While the coating was successfully applied to the glass slides, as confirmed with Raman spectroscopy, it was not possible to get the nanoparticles to adhere. Future outlook for this project is briefly reviewed.
Thesis (Master, Chemistry) -- Queen's University, 2009-06-26 10:30:58.295

博士
國立交通大學
應用化學系碩博士班
104
Small molecules can probe the biological systems thereby understanding of biological processes is possible. Hence, they have been exploited in designing drug molecules against various biological targets. The present thesis deals with the design and synthesis of heterocyclic small molecules of biological interest. The thesis is divided into three chapters for the sake of convenience and better understanding. The first chapter deals with a facile and efficient synthesis of novel oxo, thio and seleno hydantoin fused tetrahydroazepino [4, 5-b]indoles. Naturally occurring iboga class alkaloid inspired seven-member azepino[4,5-b]indole ring was synthesized as a new scaffold through Pictet-Spengler reaction followed by skeletal rearrangement of aziridine ring. To improve the efficiency of the synthetic route, the double bond of the rearranged olefinic product 1-45 was reduced and privileged hydantoin moiety was constructed on the core system through urea formation using variety of isocyanates, isothiocyanates and isoselenocyanates followed by intramolecular cyclization to incorporate elements of diversity. The regeneration of the double bond of intermediate 1-49 afforded hydantoin-fused tetrahydroazepino [4, 5-b]indoles. In the second chapter, an efficient and regioselective synthesis of novel 1,2,3-triazole-fused-1,5,-benzoxazocinones through intramolecular cyclization of substituted ethynyl triazoyl benzoic acids was explored. A crucial precursor 5-iodo-1,2,3-triazole benzoate was obtained from substituted anthranalic acid esters in a single step through CuAAC reaction using CuI/NBS catalytic system. Carbon-carbon triple bond was installed through Sonogashira coupling reaction by various terminal alkynes. Finally, the 1,4,5-substituted ethynyl triazoyl benzoic acids were obtained by AgOTf mediated intramolecular cyclization. The third chapter describes the design and synthesis of new biprivileged molecular scaffolds with diverse structural features. Commercially available, simple heterocyclic building blocks such as 4-fluoro-3-nitrobenzoic acid, 2-chloro-3-nitrobenzoic acid, and indoline were utilized for the synthesis of the novel heterocycles. Pictet–Spengler-type condensation was used as a key step to construct tetracyclic indolo-benzodiazepines and indolo-quinoxalines linked with substituted benzimidazoles. Analysis of single crystals of representative compounds showed that these molecular skeletons have the potential to present various substituents with distinct three-dimensional orientations.