Dans la technologie à l'hydrogène, l'oxydation préférentielle du CO en excès d'hydrogène (réaction PrOx) est un processus important pour l'obtention d'hydrogène sans CO pour les piles à combustible à membrane échangeuse de protons (PEMFC). Les catalyseurs à base de PtCu sont l’un des systèmes les plus étudiés pour les dispositifs mobiles en raison de leur bilan d’activité / sélectivité élevé et de leurs propriétés chimiques et mécaniques appropriées pour les procédures de démarrage / arrêt dans les conditions de fonctionnement des processeurs de combustible.Récemment, l'utilisation de catalyseurs bimétalliques Pt-Cu avec une activité et une sélectivité excellentes vis-à-vis de l'oxydation du CO a été rapportée pour la réaction PrOx. Cependant, la nature des phases actives et le rôle des deux métaux au cours de la réaction ne sont pas clairement démontrés.Pour comprendre ce système, il est nécessaire de créer un catalyseur modèle qui facilite l’étude. Ainsi, des nanoparticules d'alliage bimétallique Pt-Cu bien définies ont été synthétisées et étudiées par des techniques d'Operando permettant de comprendre les modifications électroniques de surface de l'interface solide-gaz du catalyseur modèle mentionné ci-dessus dans des conditions de réaction PrOx.Dans ce travail, la composition et la nature des espèces présentes à la surface du catalyseur dans des conditions de réaction bien contrôlées ont été étudiées, en particulier du point de vue de la dynamique de surface, des transitions structurelles et des effets possibles de l’atmosphère de réaction et des couches superposées adsorbées sur la surface. composition superficielle et structure de l'alliage. / In the Hydrogen technology, the preferential oxidation of CO in excess of hydrogen (PrOx reaction) is an important process for obtaining CO-free hydrogen for proton exchange membrane fuel cells (PEMFCs). PtCu based catalysts are one of the most studied systems for mobile devices because of their high activity/selectivity balance and their appropriate chemical and mechanical properties for the start-up/shut-down procedures during fuel processors operation conditions.Recently, the use of Pt-Cu bimetallic catalysts with excellent activity and selectivity towards CO oxidation was reported for PrOx reaction. However, there are not clear evidences off the nature of the active phases and the role of both metals during the reaction.To understand this system it is necessary to create a model catalyst which facilitates the study. Thus, well-defined Pt-Cu bimetallic alloy nanoparticles were synthetized and studied by Operando techniques allowing the comprehension of the surface electronic modifications in the solid-gas interface of the above mentioned model catalyst under PrOx reaction conditions.In this work, the composition and nature of the species present on the catalyst surface upon well-controlled reaction conditions were studied, in particular from the point of view of surface dynamics, structural transitions and the possible effects of reaction atmosphere and adsorbed overlayers on the surface composition and structure of the alloy.

Charles University in Prague, Faculty of Pharmacy in Hradci Králové Department of: Pharmaceutical technology Consultant: doc. RNDr. Pavel Doležal, CSc. Student: Lenka Horejšová Title of Thesis: Permeation of Nanoparticles Across Sublingual Membrane 4 The theoretical part describes the anatomy and physiology of oral cavity and sublingual drug administration. It also describes theory of nanotechnology and the characterization of nanoparticles with a focus on nanoparticle drug forms and there are also mentioned methods and mesuring device. . The experimental part describes in vitro permeation experiment of nanoparticles (Nano beads based on PD, Chromeon 470 marked, carboxylated). Permeation of this nanoparticles through porcine sublingual membrane (1 cm2) . Thesis compares nanoparticles transfer of phosphate buffer pH 6.6 and citrate buffer pH 6.6 to the acceptor phase consisting of phosphate buffer pH 7,4. First permeation experiment works with frozen sublingual membrane, a second experiment with the native membrane. The dimension of nanoparticles and aggregates of nanoparticles in dispersions were measured before the start of permeation by the dynamic light scattering. This work demonstrates that the choice of donor buffer has not an important influence. Key words: nanoparticles, fluorescent...

4 ABSTRACT The theoretical part describes anatomical and physiological aspects of the oral cavity, tongue and salivary glands. It captures the issue of sublingual administration of drugs. Through a brief history of nanotechnology it comes to characterize nanoparticles as basic building blocks of nanostructures. It describes the production and properties of nanoparticles, shows the advantages of using nanoparticles as a drug delivery system, but also point out their potential toxicity. At the end of the theoretical part principles and methods of measurement used in the experiments are summarized and characterized. In the experimental part in vitro permeation experiments are described and evaluated. Permeation of nanoparticles marked Chromeon 470 through porcine sublingual membrane in area of 1 cm2 from the donor phase of pH 6.6 to acceptor phase pH 7.4 was observed in these experiments. For the permeation experiments were used both fresh and long-term frozen sublingual membranes fixed in Franz diffusion cells with glue or silicone urease. Before starting the permeation experiments the size of nanoparticles or agglomerates were characterized using dynamic light scattering and by fluorescence microscopy. It was verified that the two evaluated methods of fixing of membranes in diffusion cells have no...

This diploma thesis was focused on the preparation of magnetic and fluorescently labelled spinel type nanoparticles, specifically nanoparticles of zinc-doped cobalt ferrite intended for application in magnetic resonance imaging and fluorescence microscopy in experimental practice. In previous studies, various ferrite nanoparticles exhibited relatively high transverse relaxation times and strong negative T2 contrast. These properties were also supposed for the zinc-doped cobalt ferrite nanoparticles. This assumption was confirmed by studying their magnetic and contrasting properties. Fluorescence properties of the prepared nanoparticles were also successfully studied. With respect to the intended applications of these particles, the issue of suitable surface modification of magnetic cores, their colloidal stabilization in an aqueous suspension and toxicity in biological systems were studied. Key words: nanoparticles, ferrites, MRI, relaxation

Magister Pharmaceuticae - MPharm / Background/Introduction: Atopic dermatitis (AD) is one of the most prevalent diseases worldwide. It is a rapidly growing field of study with several research avenues to explore its pathophysiology and to find innovative treatment and management regimens. Clinically, it is classified as a non-contagious, intensely pruritic, inflammatory, chronic skin disorder mediated by abnormalities associated with atopy. Symptoms include inflammation, redness, pain and a negative impact on the patient‘s overall quality of life. Chronic itching often leads to the formation of lichenified skin, which may increase the thickness of the epidermis and exacerbate the barrier function of the skin. AD is treated with topical corticosteroids which help to decrease inflammation. However, lichification of the skin may decrease the efficacy of topical dosage forms. Nanomedicine is a rapidly developing field where advances have been made using ethosomes for topical delivery. As such, corticosteroid loaded ethosomal formulations containing hydrocortiosone acetate (HCA) and betamethasone valerate (BMV) were developed and characterised to develop novel tools for topical drug delivery. Aim: This study aimed at developing corticosteroid loaded ethosomes as a pre-formulation component for inclusion in a topical dosage form. To date, no ethosmal formulation with HCA and BMV has been investigated for topical drug delivery. Method: Ethosomes were synthesised using the hot method and the cold method, a modified version of a double emulsion (o/w/o), solvent evaporation technique, as developed by Touitou et al, 2007.1 Ethosomes were prepared using fixed concentrations of either BMV or HCA (10 mg/ml), ethanol (30% v/v) and purified water (70% v/v) and were comminuted using bath sonication or mini-extrusion. Centrifugation and centrifugal drying were used to purify and isolate the ethosomes for solid state characterisation. The morphology was determined using Scanning electron microscopy (SEM). Ethosomes were characterised using: dynamic light scattering (DLS), Fourier-transform infrared spectroscopy (FTIR), hot stage microscopy (HSM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The encapsulation efficiency (EE) and drug loading (DL) were determined using validated HPLC methods. Finally, the drug release was determined using Franz diffusion cells and mathematical models were fitted to the % cumulative release data to determine the release kinetics. Results: Ethosomes were assessed according to the following criteria for topical drug delivery which were determined using dynamic light scattering (DLS): Hydrodynamic diameter (HdD), ~ 200 nm, polydispersity index (PdI) < 0.5 and zeta potential (ζp) ± 30 mV. The optimum formulations contained phosphatidylcholine (PC) 50 mg/ml. Extrusion was found to be the best method for particle reduction based on the reproducibility of the results. The HdD was 163.8±31.99 and 147.7±19.91 for BMV loaded ethosomes and HCA loaded ethosomes respectively and both formulations had an acceptable PdI of 0.049 and 0.111, respectively. SEM analyses indicated that the ethosomes had a spherical shape. Encapsulation of the APIs was verified by the thermoanalyses and possible intermolecular interactions were identified using FTIR. BMV loaded and HCA loaded ethosomes had a respective EE of 74.57 % and 37.30 %, and a DL of 14.91 % and 7.46 %, respectively. The release kinetics best fit the Peppas-Sahlin model indicative of an anomalous non-Fickian diffusion coupled with polymer relaxation and zero order release. Conclusions: BMV and HCA loaded ethosomes for topical drug delivery were successfully synthesised and characterised. These novel nanoparticles have provided an array of avenues for further investigation and application in the topical delivery of corticosteroids

Magister Scientiae (Medical Bioscience) - MSc(MBS) / Recently nanoparticles (NPs) have been introduced and used in combination with therapeutic approaches to develop nanotechnology-enabled medicine. These nanostructures allow for the exploitation of the physiochemical properties which may be beneficial in cancer treatment. The use of NPs in nanomedicine has proven successful in modern chemotherapeutics and has demonstrated promising potential in in vivo and in vitro radiosensitization studies. This is a baseline study aimed to determine the cytotoxic effects of AuNPs for potential radiosensitization analysis. The study analysed the effects of different AuNP sizes (30, 50 and 80nm), concentrations (5, 10 and 15 μg/ml) over various time periods in CHOK1 and A549 cells.

As electronic devices became smaller, interest in quantum-confined semiconductor nanostructures increased. Self-assembled mesoscale semiconductor structures of II-VI nanocrystals are an especially exciting subject because of their controllable band gap and unique photophysical properties. Several preparative methods to synthesize and control the sizes of the individual nanocrystallites and the electronic and optical properties have been intensively studied. Fabrication of patterned nanostructures composed of quantum-confined nanoparticles is the next step toward practical applications. We have developed an innovative method to fabricate diverse nanostructures which relies on the size and a shape of a chosen deoxyribonucleic acid (DNA) template.

Thesis advisor: Udayan Mohanty / The high surface area and atomic-level tunability offered by nanoparticles has defined their promise as heterogeneous catalysts. While initial studies began with nanoparticles of a single metal assuming thermodynamic shapes, modern work has focused on using nanoparticle composition and geometry to optimize nanocatalysts for a wide variety of reactions. Further optimization of these refined nanocatalysts remains difficult, however, as the factors that determine catalytic activity are intertwined and a fundamental understanding of each remains elusive. In this work, precise synthetic methods are used to tune a number of factors, including composition, strain, metal-to-metal charge transfer, atomic order, and surface faceting, and understand their impact on catalysis. The first chapter focuses on current achievements and challenges in the synthesis of intermetallic nanocatalysts, which offer long-range order that allows for total control of surface structure. A particular focus is given to the impact of the synthetic approach on the activity of the resulting nanoparticles. In the second chapter, multilayered Pd-(Ni-Pt)x nanoparticles serve as a controlled arena for the study of metallic mixing and order formation on the nanoscale. The third chapter controls the shell thickness of Au@PdPt core-alloyed shell nanoparticles on a nanometer scale to isolate strain at the nanoparticle surface. In the fourth chapter, the synthetic approaches of chapters two and three are applied to catalysis. In totality, the work presented here represents a brick in the foundation of understanding and exploiting structure-function relationships on the nanoscale, with an eye toward the rational design of tailored nanocatalysts. / Thesis (PhD) — Boston College, 2020. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

10 ABSTRACT Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Technology Consultant: PharmDr. Ondřej Holas, PhD. Student: Jiřina Blažková Title of thesis: A study of biodegradable polyesters based nanoparticles properties Nanoparticles (NPs) are particles with a diameter size ranging between 1 - 500 nm. They are preferably used as drug delivery systems or imaging systems. NPs are able to encapsulate both hydrophilic and hydrophobic drugs and also macromolecules such as peptides or mRNAs. The aim of this study was to specify selected properties of NPs prepared from poly (lactide-co-glycolide) polymer (PLGA) using polyvinyl alcohol as a surfactant. Nanoprecipitation was chosen as a preparation method. NPs were prepared from a branched PLGA copolymer and from a conventional linear PLGA polymer/oligomer. The main task was a stability study. The effect of the pH and the type of the used polymer of the nanoparticle suspension on the morphology of the nanoparticles was evaluated over one month period. The following parameters of nanoparticles with two model drugs (curcumin and procaine) were also monitored: encapsulation efficiency, drug loading and recovery yield. Dissolution tests were performer and the suitability of individual polymers for different types of drugs...

Considerable attention has been focused on nanomaterials and their extensive applications. Metallic nanoparticles, especially gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs), due to their superior physical, chemical, and optical properties, are vastly developed for numerous biomedical applications such as drug and gene delivery systems, diagnostic biosensors, imaging, and therapeutics. This study presents a low-cost method for the fabrication of self-assembled metallic nanoparticles, including gold and silver, via a reactive blade coating process, which is carried out based on in situ reduction of the metal precursors. This technique is a roll-to-roll compatible technique suitable for scalable nanomanufacturing. Oleylamine was used as a reducer agent, and gold (III) chloride hydrate and silver salts, including silver nitrate and silver perchlorate hydrate, were used as the metal precursors. Fabrication was carried out by first blade coating the reducer ink and subsequently coating the precursor ink followed by 3 hours of heat treatment. Various solvent systems were used to examine the effect of different solvents on the fabrication process. Surface morphology, crystalline phase composition, and plasmon resonance of the coated samples were characterized by scanning electron microscopy (SEM), X-ray diffractometer (XRD), and UV-Vis spectroscopy, respectively. Results demonstrated the synthesis of spherical self-assembled AuNPs using toluene (TOL) and isopropyl alcohol (IPA) for reducing and precursor solvents, respectively. Changing the concentration of reactants or increasing the coating layers exhibited a change in the average size of AuNPs. Self-assembled AuNPs thin films were also demonstrated to have the potential to be used as a biosensing platform based on localized surface plasmon resonance (LSPR) effect to detect the elevated levels of glucose in an aqueous solution. Recently, the world has faced a pandemic of Covid-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has threatened human health and has brought a worldwide devastating economic and social crisis. Hence, finding a solution to mitigate the current breakout of Covid-19 is vital to protect the international community from its causing harm. AgNPs as an antimicrobial agent, which has exhibited promising antiviral activity against several viruses, can offer a resolution to combat the spread of Covid-19. In this regard, AgNPs thin films were fabricated analogously via blade coating using various reducer and silver salt inks made of different solvent systems. Virucidal efficacy of reactive blade coated AgNPs on glass substrates was analyzed against human coronavirus 229E, a virus from the Coronavirus family, as a surrogate SARS-CoV-2 (according to the Level 2 Biosafety facility at uOttawa). Plaque forming assay indicated more than 99.99% reduction in infectivity of the virus when it contacts the AgNPs coated glass for 30 min before infecting cells. These results suggest the excellent potential for reactive blade coated AgNPs as an antiviral agent against coronavirus to avoid the spread of the virus.