Les matériaux de chaussée dits “à froid”, formés d’un mélange de granulats et d’une émulsion de bitume, constituent une alternative plus économique et respectueuse de l’environnement aux matériaux de chaussée classiques. Cependant, ces mélanges incorporent une quantité significative d’eau, retardant la consolidation du mélange granulaire. L’objectif de cette thèse est de comprendre le déroulement du séchage au sein de l’enrobé, un milieu granulaire poreux saturé en émulsion de bitume, et quel en est l’effet sur sa structure et ses propriétés. Les principaux mécanismes du séchage de milieux poreux simples initialement saturés en eau sont relativement bien connus : celui-ci se déroule selon une longue première période à vitesse constante associée à une désaturation homogène du milieu et durant laquelle environ 90% d’eau est extraite, suivie d’une période à vitesse décroissante. Quelques travaux ont récemment montré que l’on peut largement s’éloigner de ce schéma dès que le fluide interstitiel est plus complexe (solution saline, suspension, gel), du fait du transport et/ou de l’accumulation des composants non-évaporables contenus dans le fluide. Nous avons choisi de décomposer le problème en étudiant d’abord le séchage du fluide complexe seul, autrement dit l’émulsion de bitume (ainsi que des émulsions modèles de silicone afin de mieux comprendre les mécanismes), puis le séchage de cette même émulsion en milieu poreux. Notre travail s’appuie sur le suivi « macroscopique » du séchage (i.e. pesée), et un suivi des caractéristiques internes (distribution de de liquide au sein du matériau) par Imagerie par Résonance Magnétique, qui fournit des informations originales très complètes. Nous montrons ainsi que l’extraction d’eau résultant du séchage d’émulsions modèles de silicone et de bitume seules est essentiellement homogène sur toute l’épaisseur (centimétrique) de l’émulsion, et associée à la compaction et la déformation progressives des gouttes de phase dispersée. Cependant, un gradient de concentration existe près de la surface libre et il s’avère que dans cette zone la coalescence de gouttes de phase dispersée ralentit très fortement le séchage. Nous montrons ensuite que la vitesse de séchage de milieux poreux initialement saturés en émulsion diminue dès le départ et continuellement jusqu’à de très faibles valeurs. La formation et la progression rapide d’un front sec dans le milieu poreux ainsi que l’absence de migration de bitume dans le milieu poreux, observés par IRM, permettent d’expliquer en partie ce phénomène, mais il faut probablement y ajouter les caractéristiques propres du séchage de l’émulsion de bitume, qui contribuent également à ralentir la vitesse d’évaporation / The preparation of cold mix asphalts, composed of aggregates and bitumen emulsion, represent a substantial economic and environmental potential but the presence of water delays the strengthening of the material. Our objective is to understand how the mix dries and how this affects its properties. The drying of pure liquids in simple porous media has been extensively studied : a constant drying rate period as well as a homogeneous distribution of water are observed until 90% of the water has been extracted; afterwards the drying rate decreases. Studies have shown that the drying of complex fluids (ionic solutions, suspensions, gels) is very different due to the transport and/or accumulation of the fluid’s non-vaporizable elements. We chose to study first the drying of the complex fluid i.e. the bitumen emulsion as well as silicone oil emulsions to understand better the drying mechanisms, then the drying of the complex fluid in a porous media. We used Magnetic Resonance Imaging (MRI) to monitor the internal characteristics of our systems. This allowed us to show that water is extracted uniformly over the drying emulsion’s entire thickness ($approx$cm), leading to the progressive droplet compaction and deformation. However, a water concentration gradient forms near the free surface, which ultimately slows the drying as droplets coalesce. We then show that the drying rate of a porous medium initially saturated with emulsion decreases from the beginning of drying. The rapid formation and progression of a dry area in the porous medium and the absence of bitumen transport partly explain this but it is very likely that the bitumen emulsion’s drying characteristics contribute to the decreasing drying rate

Se han desarrollado y optimizado dos nanoemulsiones que contienen Nistatina (N1 y N2) para su aplicación en piel y mucosa oral, respectivamente. Estas formulaciones tuvieron un tamaño de gota nanométrico y resultaron ser estables a lo largo del tiempo. Adicionalmente se determinó el comportamiento reológico de ambos sistemas resultando ser fluidos newtonianos. Se evaluó la actividad antifúngica in vitro, observado que la potencia de la nistatina aumentó al ser introducida en las nanoemulsiones, cuando se comparaba con la nistatina libre. El mecanismo de liberación de la nistatina de las nanoemulsiones siguió una cinética de orden uno para ambas formulaciones. Trás el ensayo de permeación ex vivo en piel humana con la nanoemulsion N1 se observó que la cantidad de fármaco permeada fue muy baja, pudiendo descartarse la posible aparición de efectos adversos a nivel sistémico. De la misma manera se realizó el ensayo de permeación ex vivo en mucosa oral porcina para la formulación N2 llegando a la misma conclusión que en el caso de la permeación en piel. En ambos casos la cantidad de fármaco retenido en el tejido (tanto en piel o mucosa) es suficiente para observar un efecto fungistático, fungicida y un prolongado efecto post-antifungico (PAFE). Con el fin de determinar el efecto de la nanoemulsion N2 sobre la mucosa oral se visualizó la ultra-estructura del tejido y no observándose variaciones significativas cuando se comparaban con el control (mucosa no tratada con la nanoemulsion). Las nanoemulsiones N1 y N2 son formulaciones prometedoras para el potencial tratamiento clínico de candidiasis muco-cutáneas. / Muco-cutaneous candidosis is a common opportunistic infection must be treated to prevent other tissue invasion. Nystatin is one of the most prescribed drugs to treat this pathology, but due to its physicochemical properties its pharmaceutical-technological requirements make it a challenge. The purpose of this work was the development and characterization of an optimal nystatin delivery system for the potential treatment of oral candidosis avoiding undesirable side effects and toxicity of potential systemic absorption. Two nanoemulsion (N1 and N2) was developed, evaluated and characterized. It has been formulated successfully as a stable nanoemulsion with a droplet size of 75 and 138 nm, respectively. First order release parameters were estimated using different mathematical approaches and ex vivo permeation of nystatin through human skin and porcine buccal mucosa were found no systemic effects would happen. Microbiologic studies performed revealed an enhanced antifungal effect of the nystatin loaded nanoemulsion. Also the evaluation of buccal mucosa ultrastructure by transmission electron microscopy methodology showing a harmless effect in the mucosa microstructure. We can infer that the selected nystatin nanoemulsion could be potentially used on candidosis infection under mucositis conditions.

Les émulsions de Pickering ont suscité un intérêt croissant dans de nombreux domaines de la recherche en raison de leur grande stabilité et versatilité. Une attention particulière a été accordée à la fabrication des systèmes complexes et originaux qui peuvent être obtenus avec différentes particules. Cette étude a consisté dans l'analyse des différents paramètres physico-chimiques des particules, des milieux liquides et des systèmes dispersées, et leur relation avec le comportement mécanique et la structure des émulsions afin de prédire et de moduler les caractéristiques de ces dernières. Nous avons étudié plus particulièrement pour la première fois, le diagramme de phase concernant les inversions de phase du type catastrophique et transitionnelle des émulsions de Pickering. Nous avons utilisé des particules de silice avec des structures et hydrophobicités différentes. En particulier, nous avons montré que le mélange de particules de différente hydrophobicités peut moduler finement l'inversion de phase aussi bien que les propriétés rhéologiques et structurales des émulsions. La fabrication de membranes à partir des émulsions de Pickering précédentes a été proposée comme un exemple de l'utilisation de ces systèmes modèles pour la conception de matériaux complexes. / Pickering emulsions have gained interest in many fields of research due their properties like higher stability and versatility. Special attention has been given to the processing of complex and original systems which can be obtained by using different particles. This study consists in the analysis of the different physicochemical parameters of particles, liquid media as well dispersion systems, and their relationship with emulsions structural and mechanical behavior in order to predict and modulate the emulsions characteristics. We studied extensively for the first time the phase diagram of catastrophic and transitional phase inversion of Pickering emulsions. We used silica particles with different structure and hydrophobicity. In particular we showed that mixing particles with different hydrophobicity can finely modulate the phase inversion as well the rheological and structural properties of the emulsions. The manufacturing of emulsified membranes based on previous Pickering emulsions was proposed as an example of the use of these systems as templates for the design of complex materials.

<p>Emulsions are advantageous in many applications including healthcare, food science, and detergency due to their ability to disperse one fluid in another, otherwise immiscible fluid. For the same reason, emulsions are also problematic when mixtures of oil and water are undesirable like in industrial wastewater pollution and fuel systems. Whether an emulsion is desirable or not, both benefit from understanding the fundamental relationship of emulsion formation and stability to the physical and chemical properties of the oil-water-surfactant mixture. This work identifies the formation and stability mechanisms of model emulsion systems through the perspective of emulsion prevention for applications in shipboard wastewater (bilge water) treatment. Although experiments in this study were designed to model bilge water systems, their fundamental approach makes them practical for many different applications like food science, pharmaceuticals, and detergency.</p> <p>The impact of salts on emulsion formation and stability to coalescence were studied to understand how emulsions stabilized by ionic surfactant behave in saltwater environments. Droplet size analysis revealed that emulsion stability to coalescence improved with salt concentration. Through interfacial tension and zeta potential measurements, it was found that the addition of salt promoted close surfactant packing and faster surfactant adsorption kinetics at the oil-water interface. This aided in preventing coalescence and created conditions favorable for the formation of a stable Newton black film. Extended DLVO calculations were used to model the interaction energy between droplets and suggested that hydration forces play an important role in stabilizing these systems. These emulsions were then studied under dynamic ageing conditions to observe the impact of motion on emulsion stability. While statically aged emulsions were stable to coalescence, dynamic ageing induced coalescence (increased droplet size) or emulsified the oil droplets (decreased droplet size) depending on the surfactant concentration and energy input during ageing.</p> Formation mechanisms and stability of spontaneous emulsion systems were also investigated. Low molecular weight oils (e.g., toluene, xylenes, and cyclohexane) were found to spontaneously emulsify with nonylphenol polyethoxylated (NPE) and sodium dodecylbenzene sulfonate (SDBS). NPE emulsions spontaneously emulsified via diffusion and micelle swelling and displayed limited stability due to Ostwald ripening. SDBS emulsions also spontaneously emulsified with toluene but only in saltwater environments. As the concentration of salt in the aqueous phase increased, the spontaneity of these emulsions also increased. These systems were analyzed using the hydrophilic lipophilic difference (HLD) theory to evaluate its efficacy for predicting the conditions favorable for spontaneous emulsification. Limitations and practicality of using the HLD model for these systems were also explored.

Emulsions, comprising dispersed oil or water droplets stabilized by surfactants, are widely employed across industries. However, conventional surfactants raise environmental concerns, and emulsions may encounter stability challenges during storage. A promising alternative lies in Pickering emulsions, where particles adhere irreversibly at the water-oil interface, providing enhanced stability. Recent research explores the use of natural bio-based particles as interfacial stabilizers for creating Pickering emulsions, offering improved stability and environmental friendliness. This significant change towards particle-stabilized emulsions addresses sustainability and efficacy concerns. This dissertation investigates the application of cellulose nanofibrils (CNFs) in stabilizing Pickering emulsions for the development of functional microcapsules with diverse applications. A novel CNF aerogel with a hierarchical pore structure was developed using n-hexane-CNF oil-in-water (O/W) Pickering emulsions as templates. These hollow microcapsule-based CNF (HM-CNF) aerogels demonstrated high oil absorption capacities of 354 grams per gram for chloroform and 166 grams per gram for n-hexadecane, without requiring hydrophobic modifications, highlighting their potential as environmentally sustainable and high-performance oil absorbents. Further, the research explored the microencapsulation of n-hexadecane, an organic phase change material (PCM), within a hybrid shell of CNFs and chitin nanofibers (ChNFs). This method significantly improved the thermal stability of the encapsulated n-hexadecane, with maximum weight loss temperatures increasing from 184 degrees Celsius to 201 degrees Celsius with ChNF loading. The char yield also increased with ChNF content, indicating enhanced thermal degradation resistance. These emulsions demonstrated stability in various ionic solutions and elevated temperatures, showcasing their potential for applications such as thermal energy storage, cosmetics, food, and pharmaceuticals. Additionally, the dissertation examined stable water-in-oil (W/O) inverse Pickering emulsions using TEMPO-treated cellulose nanofibrils (TCNF). These emulsions, stabilized by TCNF-oleylamine complexes, exhibited droplet sizes ranging from 27 micrometers to 8 micrometers depending on TCNF concentration. They maintained stability under varying pH, ionic strength, and temperature conditions and demonstrated the encapsulation of water-soluble components like phytic acid, highlighting their versatility for diverse encapsulation applications. Overall, the research presents significant advancements in the utilization of CNF-stabilized Pickering emulsions, employing them as templates for fabricating aerogels and microcapsules. This approach enhances oil absorption, thermal stability, and encapsulation capabilities, offering eco-friendly solutions for diverse applications.

During the last decade high throughput DNA sequencing of single cells has evolved from an idea to one of the most high profile fields of research. Much of this development has been possible due to the dramatic reduction in costs for massively parallel sequencing. The four papers included in this thesis describe or evaluate technological advancements for high throughput DNA sequencing of single cells and single molecules. As the sequencing technologies improve, more samples are analyzed in parallel. In paper 1, an automated procedure for preparation of samples prior to massively parallel sequencing is presented. The method has been applied to several projects and further development by others has enabled even higher sample throughputs. Amplification of single cell genomes is a prerequisite for sequence analysis. Paper 2 evaluates four commercially available kits for whole genome amplification of single cells. The results show that coverage of the genome differs significantly among the protocols and as expected this has impact on the downstream analysis. In Paper 3, single cell genotyping by exome sequencing is used to confirm the presence of fat cells derived from donated bone marrow within the recipients’ fat tissue. Close to hundred single cells were exome sequenced and a subset was validated by whole genome sequencing. In the last paper, a new method for phasing (i.e. determining the physical connection of variant alleles) is presented. The method barcodes amplicons from single molecules in emulsion droplets. The barcodes can then be used to determine which variants were present on the same original DNA molecule. The method is applied to two variable regions in the bacterial 16S gene in a metagenomic sample. Thus, two of the papers (1 and 4) present development of new methods for increasing the throughput and information content of data from massively parallel sequencing. Paper 2 evaluates and compares currently available methods and in paper 3, a biological question is answered using some of these tools. / <p>QC 20160127</p>

<p>Mikrokapsule, kao nosači aktivnih supstanci, imaju sve veću primenu u različitim granama industrije, naročito prehrambene i farmaceutske. Inkorporiranje biolo&scaron;ki aktivnih supstanci unutar mikrokapsula omogućava maskiranje neprijatnih mirisa i ukusa, za&scaron;titu osetljivih i lako isparljivih komponenata.<br />Cilj ove doktorske disertacije je dobijanje mikrokapsula za istovremeno inkorporiranje hidrosolubilnih i liposolubilnih aktivnih materija, radi njihove za&scaron;tite i kontrolisanog otpu&scaron;tanja. Mikrokapsule su formirane iz duplih emulzija tipa voda-ulje-voda (V/U/V) metodom koacervacije, odnosno deponovanjem koacervata, koji nastaje u sistemu dva suprotno naelektrisana proteina, želatina i natrijum kazeinata (NaKN), na granicu faza ulje/voda. Kao model supstance za hidrosolubilne i liposolubilne biolo&scaron;ki aktivne materije, kori&scaron;ćeni su vitamini C i E.<br />Najpre su detaljno ispitane interakcije u sistemu želatin/NaKN primenom različitih metoda (merenje zeta potencijala, tenziometrija, viskozimetrija, reolo&scaron;ka ispitivanja). Na osnovu ovih rezultata definisane su promene, kako na granici faza, tako i unutar rastvora, kao i mehanizama formiranja koacervata između ova dva suprotno naelektrisana proteina. Utvrđeno je da se pri masenom odnosu želatin:NaKN od 2:1 dolazi do formiranja nerastvornog koacervata. Ispitan je uticaj interakcija u ovom sistemu na osobine duplih, V/U/V emulzija dobijenih emulgovanjem primarnih voda/ulje (V/U) emulzija u sme&scaron;i želatin/NaKN, pri njihovim odabranim masenim odnosima i zaključeno je da interakcija između proteina u kontinualnoj fazi utiče na<br />osobine emulzija.<br />S obzirom da je prvi korak ka dobijanju stabilne V/U/V emulzije, dobijanje stabilne primarne V/U emulzije, ispitana je mogućnost primene lipofilnih emulgatora, poliglicerol poliricinoleata (PGPR) i poliglicerol estra jestivih masnih kiselina i njihovih sme&scaron;a, za dobijanje 20% V/U emulzija. Ispitivanjem uticaja sastava sme&scaron;e emulgatora i njegove koncentracije na formiranje adsorpcionog sloja na graničnoj povr&scaron;ini ulje/voda i osobine formiranih V/U emulzija odabran je najpogodniji sistem za stabilizaciju primarnih emulzija.<br />Nakon formulisanja stabilnih duplih V/U/V emulzija sa inkorporiranim vitaminima C i E, optimizovani su uslovi za dobijanje mikrokapsula umrežavanjem kompleksa proteina na kapima ulja pomoću genipina, a njihovo izdvajanje iz rastvora ostvareno je primenom Spray drying postupka. Karakterizacijom dobijenih mikrokapsula (ispitivanjem morfologije povr&scaron;ine, efikasnosti inkapsulacije vitamina C i E, kinetike otpu&scaron;tanja vitamina C u in vitro uslovima) zaključeno je da na osobine mikrokapsula utiče koncentracija umreživača, kao i interakcija između želatina i NaKN u kontinualnoj fazi emulzija V/U/V.</p> / <p>Microcapsules, as active substance carriers, have increasing application in different industries, especially in food and pharmaceutical industry. Incorporation of the biologically active substances inside the microcapsules allows masking of unpleasant taste and smell, protection od sensitive and volatile components.<br />The aim of this thesis is preparation of microcapsules for parallel incorporation of water and oil soluble active substances for their protection and controlled release. Microcapsules were formed from double water-oil-water emulsions (W/O/W) by coacervation method, depositing the coacervate formed in the system of two oppositely charged proteins, gelatin and sodium caseinate (NaCN), at the water/oil interface. As a model for water and oil soluble biological active substances, vitamins C and E were used.<br />First of all, interactions in the gelatin/NaCN system were investigated in detail, by using different methods (measuring of zeta potential, tensiometry, vicometry, rheological investigations). Based on these results, changes at the interface and in the bulk of the system, as well as mechanisms of coacervate formation were defined. It has been determined that at gelatin:NaCN mass ratio of 2:1 non soluble coacervate were formed.<br />Influence of the interactions in this system on properties of the W/O/W double emulsions, made by emulsification of primary water/oil (W/O) emulsions in gelatin/NaCN mixtures, at desired mass ratios of proteins, was investigated. It was concluded that interactions between proteins in continuous phase of emulsions have influence on their properties.<br />As the first step in formation of stable W/O/W emulsions is<br />obtaining stable primary W/O emulsion, possibility of using lipophilic emulsifiers, polyglycerol polyricinoleate (PGPR) and polyglycerol esters of edible fatty acids and their mixtures, for 20% W/O emulsions formation were investigated. Results of these investigations showed that composition of emulsifiers mixtures and their concentrations have an influence on adsorption layer, at the water/oil interface, formation, as well as on stability of W/O emulsion, and based on these results the most suitable system of emulsifiers were chosen.<br />After formulation of stable double W/O/W emulsions with incorporated vitamins C and E, conditions for microcapsules formation, by crosslinking of proteins complex at oil droplets with genipin, were optimized, and for their separation from dispersion spray drying method was applied. Characterization of obtained microcapsules (investigation of the surface morphology, efficiency of the vitamins C and E encapsulation, release kinetics of vitamin C under in vitro conditions) showed that concentration of crosslinking agent, as well as interaction between gelatin and NaCN, have an influence on microcapsules properties.</p>

The diploma thesis is focused on the study of influence on the composition of the system to the size of the nanoparticles from aliphatic polyesters with linear and branched molecules constitution. The emulsion method for distributing of solvent was chosen for preparation of nanoparticles. The theoretical part describes the nanoparticles, its origin and application. The following part is applying to biodegradable polymers, especially PLGA. There is also a mention of antifungal agent terbinafine. The nanoparticles are prepared of this substance. The process is described in the experimental part of thesis. The experimental part is testing different composition of samples. A main emphasis is on the choice of polymer solvent and emulsifier. There are also applied mixtures of solvents and emulsifiers. The important aspect is the evaluation of incorporated terbinafine, which has been the model drug. Prepared dispersions were exposed to stress conditions in the form of several days-storage and centrifugation.

In the theoretical part of this thesis are described various types of nanoparticles, such as polymeric particles, liposomes, micelles and solid lipid nanoparticles. There are presented basic informations concerning methods of particles preparation in the laboratory conditions such as solutions of polymers dispersion methods by intensively stirring, coacervation of the solutions of polymers, polymeration methods in dispersions, and the exploitation of methods of dispersion of polymeric solutions in the supercritical solvents. In the folowing part of this thesis are some concise informations about the methods of evaluation of basic parameters of the nanoparticulate systems. There are summarised the trivial informations concerning granulometry of particles, their zeta potential, encapsulation effectivity of drugs, and also about the particles shape factor. The focus of this thesis is in the experiment, the main deal were in minimisation of the particle size prepared by the method of emulsification of biodegradable aliphatic α-hydroxyacids polyesters solutions. The main process arrangement was the selection of the appropriate solvent of polymers in the inner emulsion phase and the founding for the mostly efficient emulsifier during the dispersion process of polymer solutions. In process of the...

Charles Univerzity in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Candidate: Dana Svobodová Supervisor: doc. RNDr. Milan Dittrich, CSc. Diploma thesis title: Particles with antimicrobial silver The theoretical part of this diploma thesis outlines a brief overview of recent findings on silver nanoparticles. Further, it concerns the kinetic properties of colloidal systems, methods of evaluating the size and shape of colloidal particles, mechanism of antimicrobial activity of colloidal silver and methods of preparation of nanoparticles. Concise information about the toxicity of silver nanoparticles and their impact on the environment is also included. In the experimental part comprehensive report on the results of measurements of granulometric characteristics of microparticles and nanoparticles by photon correlation spectroscopy (PCS) is included. The influence of various modifications of preparation procedures and processing on stability, size and the polydispersity of the size in terms of the volume and intensity diameter of the particles with elemental silver deposited on the surface was studied. Optimisation of the disperse system, quality control of the content of colloidal particles by subsequent reduction, the possibilities of using centrifuge and...