No description available.

Lipid structures, such as liposomes or micelles, are of high interest as an approach to support the transport and delivery of active agents as a drug delivery system. However, there are many open questions regarding their uptake and impact on cellular metabolism. In this study, lipid structures were assembled as a supported lipid bilayer on top of biopolymer-coated microcarriers based on the Layer-by-Layer assembly strategy. The functionalized microcarriers were then applied to various human and animal cell lines in addition to primary human macrophages (MΦ). Here, their influence on cellular metabolism and their intracellular localization were detected by extracellular flux analysis and immunofluorescence analysis, respectively. The impact of microcarriers on metabolic parameters was in most cell types rather low. However, lipid bilayer-supported microcarriers induced a decrease in oxygen consumption rate (OCR, indicative for mitochondrial respiration) and extracellular acidification rate (ECAR, indicative for glycolysis) in Vero cells. Additionally, in Vero cells lipid bilayer microcarriers showed a more pronounced association with microtubule filaments than polymer-coated microcarrier. Furthermore, they localized to a perinuclear region and induced nuclei with some deformations at a higher rate than unfunctionalized carriers. This association was reduced through the application of the microtubule polymerization inhibitor nocodazole. Thus, the effect of respective lipid structures as a drug delivery system on cells has to be considered in the context of the respective target cell, but in general can be regarded as rather low.

No description available.

No description available.

Organische Solarzellen bieten die Aussicht auf eine ökologische und zugleich ökonomische Energiequelle. Nachteile des Konzepts liegen in der z.T. geringen Stabilität der für Absorption und Ladungstransport verwendeten Moleküle und einer unvollständigen Ausnutzung des Sonnenspektrums. Zur Verbesserung beider Merkmale werden in dieser Arbeit einzelne organische Bestandteile durch anorganische Materialien mit hoher Stabilität und breiten Absorptionsbanden ersetzt. Insbesondere werden als Absorber kolloidale Quantenpunkte (QP) verwendet, denen aufgrund nicht-linearer und durch Größeneffekte steuerbarer optischer Eigenschaften in der Photovoltaik der dritten Generation großes Interesse gilt. Dazu werden dünne anorganisch-organische Filme mit einem Verfahren hergestellt, das auf Wechselwirkungen zwischen Partikeln in Lösung und geladenen Oberflächen beruht (electrostatic layer-by-layer self-assembly). TiO2-Nanokristalle als Elektronenleiter, kolloidale CdTe- und CdSe-QP als Absorber und konjugierte Polymere als Lochleiter werden in die Filme integriert und diese als aktive Schichten in photovoltaischen Zellen verwendet. Die Struktur der Filme wird zunächst mittels AFM, SEM, XPS sowie durch eine Beladung mit organischen Farbstoffen untersucht. Sie weisen Porosität auf einer Skala von Nanometern sowie eine kontrollierbare Dicke und Mikrostruktur auf. Darauf aufbauend werden durch weitere lösungsbasierte Prozessschritte photovoltaische Zellen gefertigt und Zusammenhänge zwischen Struktur und Zellenleistung elektronisch und spektroskopisch untersucht. Einflussfaktoren der Zelleffizienz wie die Ladungsträgererzeugung und interne Widerstände können so bestimmt und die Effizienz von CdSe-QP als Sensibilisatoren nachgewiesen werden. Die Arbeit demonstriert die Eignung der gewählten Methoden und Zelldesigns zur Herstellung von photovoltaischen Zellen und eröffnet neue Ansätze für die Entwicklung und Fertigung insbesondere auf QP basierender Zellen. / Organic solar cells offer the prospect of a both ecological and economical energy source. Drawbacks of the concept are low stabilities of the molecules used for absorption and charge transport and an incomplete utilization of the solar spectrum. In order to improve both these characteristics, individual organic components are replaced by inorganic materials with a high stability and broad absorption bands in this work. In particular, colloidal quantum dots (QDs) are used as absorbers, the non-linear and size controllable optical properties of which are attracting great interest in third generation photovoltaics. For this application, inorganic/organic thin films are produced with a method based on interactions between particles in solution and charged surfaces (electrostatic layer-by-layer self-assembly). TiO2-nanocrystals as electron conductors, colloidal CdTe- and CdSe-QDs as absorbers and conjugated polymers as hole conductors are integrated into the films, which are used as active layers in photovoltaic cells. The structure of the films is investigated by AFM, SEM, XPS and by loading the films with organic dye molecules. The films show porosity on a nanometer scale as well as a controllable thickness and microstructure. Complemented by further solution based processing steps, photovoltaic cells are manufactured and correlations between the structure and performance of the cells are investigated both electronically and spectroscopically. Individual factors that determine the cell efficiency, such as carrier generation and internal resistances, are determined and the efficiency of CdSe-QDs as sensitizers is demonstrated. This work proves the suitability of the chosen methods and cell designs for manufacturing photovoltaic cells and opens up new approaches for the development and manufacture of in particular QD-based solar cells.

[ES] La ingeniería tisular ha evolucionado hacia el modelado de la fisiología humana in vitro. El microambiente de la médula ósea (BM) es también hogar de procesos malignos. El mieloma múltiple (MM) es una neoplasia hematológica caracterizada por proliferación y acumulación en la BM de células plasmáticas monoclonales. Los tratamientos han mejorado, sin embargo, sigue siendo incurable. Moléculas de la matriz extracelular como fibronectina (FN) o ácido hialurónico (HA) tienen un papel reconocido en la resistencia a fármacos (DR). La inadecuación de los modelos preclínicos bidimensionales es una de las bases del problema de DR. Se han intentado diferentes enfoques in vitro, sin embargo, se basan en hidrogeles y andamios celulares diseñados para células adherentes, mientras que las células de MM presentan crecimiento en suspensión. El objetivo principal de esta Tesis es desarrollar, optimizar y validar una plataforma de cultivo 3D, denominada microgel, basada en microesferas en un medio líquido y que coexisten con células de MM creciendo dinámicamente en suspensión. Se desarrollaron y caracterizaron diferentes microesferas con diferentes funcionalizaciones. Optimizamos un protocolo de polimerización en suspensión para la obtención de microesferas a base de acrilatos con dos composiciones diferentes (presencia (10%) o ausencia (0%) de ácido acrílico (AA)) i dos distribuciones de tamaño diferentes (< 60 y > 70 ¿m). La FN se adsorbió en la superficie de la microesfera, mientras que el HA, colágeno I y diferentes secuencias peptídicas se injertaron covalentemente. Se modificaron las microesferas comerciales Cytodex 1 para adaptar sus características a la plataforma. Se utilizaron técnicas capa por capa (LbL) para introducir HA y sulfato de condroitina (CS) en su superficie. Por tanto, se ha generado un amplio repertorio de microesferas para desarrollar microgeles. Se optimizaron y validaron las condiciones de cultivo para la plataforma de microgel. Las condiciones óptimas se establecieron como 150 rpm de velocidad de agitación utilizando un agitador orbital y microesferas de < 60 ¿m. Los microgeles con diferentes composiciones y funcionalizaciones permitieron una buena proliferación de las líneas RPMI8226, U226 y MM1.S. Todos los sistemas respetaron el patrón de crecimiento en suspensión, factor que ha demostrado ser clave para su buen desempeño en cultivo 3D. En estudios iniciales de DR, la línea celular RPMI8226 cultivada en microgeles que contenían AA mostró una resistencia significativamente mayor a la dexametasona que sus cultivos en suspensión. Y las líneas RPMI8226, U226 y MM1.S cultivadas en microgeles que contenían AA mostraron una resistencia significativamente mayor a bortezomib que sus cultivos en suspensión. Por lo tanto, la presencia de AA en la matriz polimérica mostró un efecto positivo en la generación de DR in vitro y requerirá más estudios. Se ha validado la reducción de escala del sistema para trabajar con volúmenes más pequeños de microesferas y números reducidos de células, lo que es de gran relevancia para su traslación clínica. Finalmente, se han realizado cultivos preliminares con la línea celular RPMI8226 en los microgeles basados en Cytodex 1. Las microesferas de Cytodex 1 sin modificación tuvieron un efecto negativo sobre la viabilidad de las células de MM. La modificación mediante LbL con los pares quitosano/CS y quitosano/HA aumentó la viabilidad y proliferación. Sin embargo, estos sistemas no respetaron el carácter no adherente de las células MM. Hemos desarrollado y validado un novedoso sistema de cultivo basado en un medio 3D semisólido definido por microesferas y células de MM especialmente diseñado para células en suspensión. Este sistema constituye una herramienta versátil que debe explorarse más a fondo para el cultivo 3D de neoplasias hematológicas y para estudios de resistencia a fármacos in vitro. / [CAT] L'enginyeria tissular ha evolucionat cap al modelat de la fisiologia humana in vitro. El complex microambient de la medul·la òssia (BM) és també llar d'alguns processos malignes. El mieloma múltiple (MM) és una neoplàsia hematològica caracteritzada per una proliferació i acumulació a la BM de cèl·lules plasmàtiques monoclonals. Els tractaments han millorat, no obstant, el MM segueix sent incurable. Molècules de la matriu extracel·lular com fibronectina (FN) o àcid hialurònic (HA) tenen un paper reconegut en la generació de resistència a fàrmacs (DR) en MM. La inadequació dels models preclínics bidimensionals és una de les bases del problema de DR. Per això, s'han intentat diferents aproximacions in vitro, tanmateix es basen en hidrogels i andamis cel·lulars dissenyats per a cèl·lules adherents, mentre que les cèl·lules de MM presenten creixement en suspensió. L'objectiu principal d'aquesta Tesi és desenvolupar, optimitzar i validar una plataforma de cultiu 3D, denominada microgel, basada en microesferes en un medi líquid i que coexisteixen amb cèl·lules de MM que creixen dinàmicament en suspensió. S'han produït i caracteritzat diferents microesferes amb diferents funcionalitzacions. S'ha optimitzat un protocol de polimerització en suspensió per a l'obtenció de microesferes d'acrilats amb dues composicions diferents (presència (10%) o absència (0%) d'àcid acrílic (AA)) i amb dos distribucions de diàmetres diferents (< 60 y > 70 ¿m). La FN es va adsorbir, mentre que el HA, el col·lagen I i diferents seqüències peptídiques es van unir covalentment. S'han modificat microesferes comercials Cytodex 1 per tal d'adaptar les seves característiques a la plataforma del microgel. Mitjançant tècniques capa a capa (LbL) s'han introduït HA i sulfat de condroïtina (CS) a la seua superfície. Per tant, s'ha generat un ampli repertori de microesferes per desenvolupar microgels. Es van optimitzar i validar les condicions de cultiu per a la plataforma de microgel. Les condicions òptimes de cultiu es varen establir com a 150 rpm de velocitat d'agitació utilitzant un agitador orbital i microesferes de < 60 ¿m. Els microgels amb diferents composicions i funcionalitzacions van permetre una bona proliferació de les línies RPMI8226, U226 i MM1.S. Tots els sistemes van respectar el patró de creixement en suspensió, factor que ha demostrat ser clau per al seu bon rendiment en cultius 3D. En estudis inicials de DR línia cel·lular RPMI8226 cultivada en microgels que contenien AA va mostrar una resistència significativament major a la dexametasona que els seus cultius en suspensió convencionals. Línies RPMI8226, U226 y MM1.S cultivades en microgels que contenien AA mostraren una resistència significativament major a bortezomib que els seus cultius en suspensió convencionals. Per tant, la presencia d'AA a la matriu polimèrica de les microesferes va mostrar un efecte positiu en termes de generació de DR in vitro, cosa que requerirà estudis futurs. S'ha validat la reducció de l'escala del sistema per treballar amb volums més petits de microesferes i menys cèl·lules, el que és de gran rellevància per a la seva translació clínica. Finalment, s'han realitzat cultius preliminars amb la línia cel·lular RPMI8226 en els microgels basats en les Cytodex 1. Les microesferes de Cytodex 1 sense modificar van mostrar efecte negatiu sobre la viabilitat de les cèl·lules de MM. La modificació mitjançant LbL amb els parells quitosà/CS i quitosà/HA va augmentar la viabilitat i proliferació de cèl·lules MM. No obstant, aquests sistemes no respectaren el caràcter no adherent de les cèl·lules de MM. S'ha desenvolupat i validat un nou sistema de cultiu cel·lular basat en un medi 3D semisòlid definit per microesferes i cèl·lules de MM, especialment dissenyat per a cèl·lules no adherents. Aquest sistema constitueix una eina versàtil que ha de ser explorada per al cultiu 3D de neoplàsies hematològiques i per a estudis de resistència a fàrmacs in vitro. / [EN] Tissue engineering has evolved towards modeling of human physiology in vitro. The bone marrow (BM) microenvironment is likewise the home of some malignant processes. Multiple myeloma (MM) is a hematological neoplasia characterized by proliferation and BM accumulation of monoclonal plasma cells. Treatments have improved; however, MM remains incurable. Extracellular matrix molecules such as fibronectin (FN) or hyaluronic acid (HA) have a recognized role in drug resistance (DR). The inadequacy of two-dimensional preclinical models is one cause of the DR problem, different in vitro approaches have been developed, however, all these studies are based on hydrogels and scaffolds designed for adherent cells while MM cells are suspension growing cells. The main objective of this Thesis is to develop, optimize and validate a 3D culture platform, termed as microgel, based on microspheres suspended in a liquid media and coexisting with MM cells growing dynamically in suspension. Different microspheres with different functionalities were developed and characterized. We optimized a suspension polymerization protocol for the obtention of acrylates-based microspheres with two different compositions: with presence (10%) or absence (0%) of acrylic acid (AA). We obtained two different size distributions (< 60 and > 70 ¿m). FN was adsorbed on microsphere surface, while HA, collagen I and different peptide sequences were covalently grafted. Commercial Cytodex 1 microspheres were modified to adapt their characteristics to the microgel platform. Layer-by-layer (LbL) technics were used to introduce HA and chondroitin sulfate (CS) on Cytodex 1 surface. Therefore, a wide repertoire of microspheres has been generated to develop microgels. The culture conditions for the microgel platform were optimized and validated. Agitation is needed to keep microspheres and cells in suspension. Optimal culture conditions were 150 rpm of stirring speed using orbital shaker and < 60 ¿m diameter microspheres. Microgels with different compositions (0% AA, 10% AA) and functionalizations (none, HA, FN, collagen 1 and peptide sequences) allowed good proliferation of RPMI8226, U226 and MM1.S cells under 3D conditions. All the 3D systems respected the suspension growth pattern which appears as key factor for their good performance in 3D culture. In the initial DR studies, we found that MM cell line RPMI8226 cultured in microgels containing AA showed significantly higher resistance to dexamethasone than their conventional suspension cultures. And that MM cell lines RPMI8226, U226 and MM1.S cultured in microgels containing AA showed significantly higher resistance to bortezomib than their conventional suspension cultures. Thus, AA in the polymeric microsphere matrix showed a positive effect on the generation of DR in vitro and will require further studies. The scale-down of the system to work with smaller volumes of microspheres and reduced cell numbers has been validated, this is of great relevance for their clinical application. Finally, preliminary cultures with the cell line RPMI8226 have been performed with the Cytodex 1-based microgels. Cytodex 1 microspheres without modification had a negative effect on MM cells viability. LbL modification with the pairs chitosan/CS and chitosan/HA increased MM cells viability and proliferation. However, these systems did not respect the non-adherent character of MM cells. We have developed and validated a novel cell culture system based on a semi-solid 3D media defined by microspheres and MM cells which is specially designed for cells in suspension. It represents a versatile tool that should be further explored for the 3D culture of hematological malignancies and drug resistance studies in vitro. / Me gustaría agradecer al Servicio de Microscopía de la UPV y a sus técnicos por su valiosa ayuda con las técnicas de microscopía electrónica, a la Agencia Estatal de Investigación (proyecto PID2019-106099RB-C41 / AEI / 10.13039/501100011033) y al Ministerio de Ciencia, Innovación y Universidades (ayuda predoctoral FPU17/05810) que han financiado esta Tesis. / Clara Trujillo, S. (2022). Development of a 3D in Vitro Disease Model for Multiple Myeloma [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/186054

Fluffmassa är, i ordets rätta bemärkelse, ett fluffigt material som i de allra flesta fall tillverkas av fibrer ifrån trä, den utgör en viktig del i blöjor, hygienprodukter, näsdukar och ett flertal andra produkter. Syftet med fluffmassa i absorptionsprodukter är framförallt att sprida vätskan, öka absorbtionshastigheten och behålla superabsorberande polymerer på plats i nätverket. Två viktiga kvalitetsparametrar hos fluffmassan är defibreringsenergi och knuthalt. Dessa är korrelerade till hur enkelt fibrerna kan separeras ifrån varandra i torr eller fuktad luft. Denna separation av fibrer är ett högst avgörande steg för att skapa den fluffiga massan ifrån torkade massaark.  Målet med arbetet har varit att reducera defibreringsenergin och knuthalten genom att behandla massa med oorganiska partiklar genom att använda den sk. lager-på-lager (LbL) – metoden där en konsekutiv behandling av fibrerna med motsatt laddade polyelektrolyter och nanopartilkar. Genom att belägga fiberytan med tunna skikt av ett oorganiskt material var avsikten att reducera fiber-fiber-interaktionerna för att slutligen minska defiberingsenergin och knuthalten. Studien visade att en viss effekt kunde uppnås med LbL-skikt av pDADMAC (diallyldimetylammonium klorid) och MMT (montmorillonit) vilket noterades som en minskning av knuthalten från 35% till ungefär 20%, medan defibreringsenergin däremot var oförändrad jämfört med ett obehandlat referensprov. De bildade lagren visade sig vara tunnare och jämnare än förväntat vilket sannolikt ledde till en relativt liten minskning av kontaktyta och molekylär adhesion mellan fibrerna vilket kan förklara den relativt sett låga effekten av tillsatserna. De tunna lagren kan också vara en förklaring till varför ingen nämnvärd skillnad detekteras för olika antal av bildade bilager. Eftersom enbart maximalt 3 bilager studerades kan det vara rimligt att anta att en ytterligare adsorption av bilager kan leda till en ytterligare minskning av knuthalten och defibreringsenergin.  Eftersom MMT-partiklarna inte var direkt synliga i SEM-analyserna är det svårt att säga exakt hur de är fördelade på fiberytan. Antingen är de jämnt fördelade eller så har vissa områden på fiberytan inte blivit täckta av MMT.  Resultaten indikerar också att det finns många intressanta sätt att förbättra lagren för att nå lägre defibrerinsergier och knuthalter. Genom att tex. adsorbera större partiklar istället för tunna MMT-partiklar skulle det vara möjligt att skapa en högre ytråhet och därmed en minskad kontaktyta mellan fibrerna vilket i sin tur skulle kunna minska knuthalten och defibreringsenergin. / Fluff pulp is indeed a fluffy material, it is most commonly composed of pulp fibers from wood and it serves as a vital constituent in diapers, feminine hygiene products, napkins and a variety of other products. The purpose of fluff pulp in absorbent products is mainly to distribute fluids, increase absorption speed and hold superabsorbent polymers within the network. Two important quality parameters of fluff pulp are the defibration energy and the knot content, which are related to the ease at which the fibers can be separated from each other under dry to moist conditions. This separation of fibers is an essential step in generating the fluffy material from sheets.   This project aims to reduce the defibration energy and the knot content by treating fibers with inorganic particles according to the Layer-by-Layer (LBL) technique. The main assumption was that by applying coatings to the fibers, the inter-fiber interactions can be reduced leading to a lowered defibration energy and knot content. The study showed that some effect was accomplished using layers of pDADMAC (diallydimethylammoinium chloride) and MMT (montmorillonite clay), the knot content was reduced from 35% to around 20%, but the defibration energy was unchanged compared to the untreated reference sample. The formed LBL layers appeared to be thinner and smoother than anticipated which likely lead to only a slight decrease in contact area between the fibers, hence, the reduction of knot content was detectable but not very large. Since the formed LBL layers were so thin it was difficult to find any distinguishable difference for the different numbers of bilayers, however, the maximum number of bilayers produced was only three and additional layers could lead to an amplified effect.  Since the MMT particles could not be clearly visualized from the SEM instruments, it is difficult to conclude exactly how the clay platelets were distributed on the fibers. Either the MMT was distributed rather evenly across the surface of the fibers, or some areas of the fibers were left free from LbLs.   The results from the present investigation show that there are many interesting ways to further improve the layers to reach lower defibration energies and knot contents. As an example the adsorption of larger particles instead of thin MMT platelets could be used allowing for a minimization of the contact area between the fibers due to an increased surface roughness of to the fiber surfaces.

Submitted by Milena Rubi (milenarubi@ufscar.br) on 2016-11-01T17:21:21Z No. of bitstreams: 1 GRAÇA_Juliana_2016.pdf: 30861843 bytes, checksum: d0a3ae0ba919e89cac0abf5511fb0fd6 (MD5) / Approved for entry into archive by Milena Rubi (milenarubi@ufscar.br) on 2016-11-01T17:21:34Z (GMT) No. of bitstreams: 1 GRAÇA_Juliana_2016.pdf: 30861843 bytes, checksum: d0a3ae0ba919e89cac0abf5511fb0fd6 (MD5) / Approved for entry into archive by Milena Rubi (milenarubi@ufscar.br) on 2016-11-01T17:21:49Z (GMT) No. of bitstreams: 1 GRAÇA_Juliana_2016.pdf: 30861843 bytes, checksum: d0a3ae0ba919e89cac0abf5511fb0fd6 (MD5) / Made available in DSpace on 2016-11-01T17:22:03Z (GMT). No. of bitstreams: 1 GRAÇA_Juliana_2016.pdf: 30861843 bytes, checksum: d0a3ae0ba919e89cac0abf5511fb0fd6 (MD5) Previous issue date: 2016-03-08 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / In the present work, Layer-by-Layer films of Anti-PSA antibody in the absence and presence of DPPG liposomes were produced in order to study the detection of prostate specific antigen (PSA) by different characterization techniques. The free Anti-PSA antibody in solution and incorporated into liposome was characterized by UV-vis spectroscopy and Circular Dichroism (CD). In the first characterization, it was verified the main absorption bands of the antibody and a possible aggregation in the absence of the liposome. CD measurements indicated disordered structures of free antibody. However, its secondary structure (ß-Sheet) was maintained in the presence of liposomes. The film Layer- by-Layer of free Anti-PSA antibody and incorporated into DPPG liposomes was done alternating the antibody with different polycations, PAH (poly (allylamine hydrochloride)) and PEI (poly (ethyleneimine)). The films fabricate on quartz and gold sensors were characterized by UV-vis and SPR spectroscopy. These results proved the deposition of the materials on different substrates and the PEI was the best polyelectrolyte for immobilization of the antibody. Through the SPR measures it was simulated thickness and refractive index of the film bilayers. The PEI, PVS and Anti-PSA casting film and PEI/PVS and PEI/Anti-PSA LbL films were characterized by FTIR, it was observed through the bands of the spectra the interaction between the polyelectrolyte and found the deposition of antibody in the film. Acting as PSA detection unit, the (PEI/PVS)1/(PEI/Anti-PSA+DPPG)5 and (PEI/PVS)1/(PEI/Nati-PSA)5 films were characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and SPR and both systems were able to detect PSA at concentrations below 4 ng.mL-1 that is the normal concentration for a healthy individual. / No presente trabalho foram produzidos filmes nanoestruturados camada por camada (LbL) de anticorpo Anti-PSA na ausência e na presença de lipossomos de DPPG, a fim de estudar a detecção do antígeno prostático específico (PSA) por diferentes técnicas de caracterização. A solução de anticorpo Anti-PSA, livre e incorporado em lipossomo, foi caracterizada por espectroscopia UV-vis e Dicroísmo Circular (CD). Sendo que no primeiro caso, foram verificadas as principais bandas de absorção do anticorpo e uma possível agregação na ausência do lipossomo. As medidas de CD indicaram estruturas desordenadas do anticorpo livre e na presença do lipossomo o anticorpo manteve a sua estrutura secundária (Folha-ß). Os filmes LbL de anticorpo Anti-PSA e Anti-PSA+DPPG, alternados com diferentes policátions, PAH (poli(alilamina hidroclorada)) ou PEI (poli(etilenoimina)) foram fabricados sobre quartzo e o sensor de ouro modificado com 11-MUA e caracterizados por espectroscopia UVvis e Ressonância Plasmônica de Superfície (SPR), no qual foi constatado a deposição dos materiais nos diferentes substratos e definido o PEI como melhor polieletrólito para imobilização do anticorpo. Através das medidas de SPR também foi simulado a espessura e o índice de refração das bicamadas de filmes. Os filmes casting de PEI, PVS e Anti-PSA e os filmes LbL destes materiais foram caracterizados por Espectroscopia de Absorção no Infravermelho com Transformada de Fourier (FTIR), através das bandas dos espectros no modo de transmissão e reflexão verificou-se a interação entre os polieletrólitos e constatou a deposição do anticorpo no filme. Atuando como unidade de detecção do PSA os filmes de (PEI/PVS)1/(PEI/Anti-PSA+DPPG)5 e de (PEI/PVS)1/(PEI/Nati-PSA)5 foram caracterizados por voltametria cíclica (VC), espectroscopia de impedância eletroquímica (EIE) e por SPR, e, ambos sistemas foram capazes de detectar o PSA em concentrações inferiores a 4 ng.mL-1 que é a concentração normal para um indivíduo saudável. / 2013/23288-0

L’objectif de cette étude a été de formuler et caractériser des émulsions simples huile/eau d’intérêt pharmaceutique stabilisées par de la β-lactoglobuline (β-lg), de la gomme arabique (GA), de la gomme xanthane (GX) et des mélanges β-lg:GA et β-lg:GX. Les concentrations massiques totales des dispersions de biopolymères étaient de 1 % et ont été augmentées à 2,5 % si les émulsions formulées n’étaient pas stables. Le mélange β-lg:GA a été réalisé à pH 4,2 afin de permettre la formation de complexes par interactions électrostatiques attractives entre la β-lg et la GA. Deux ratios β-lg:GA ont été étudiés : 2:1 et 1:2. Enfin, le mélange β-lg:GX a été effectué à pH 7, où les deux biopolymères étant chargés négativement ne se complexent pas et à un ratio de 1:1. Une étude de stabilité des émulsions a été menée sur 6 mois. Les stabilités obtenues ont pu être classées par ordre croissant : GA 2,5 % < β-lg:GA 2,5 % < β-lg 2,5 % < GX 1 % = β-lg:GX 1 %. Plusieurs mécanismes de stabilisation ont été mis en évidence grâce à l’étude des propriétés interfaciales des biopolymères, à l’étude des propriétés rhéologiques des émulsions et à des observations au microscope confocal à balayage laser des émulsions après marquage des biopolymères à la fluorescence. La β-lg et la GA sont toutes deux capables de s’adsorber à l’interface des globules huileux alors que la GX augmente la viscosité de la phase continue. L’association β-lg:GA conduit à la formation d’une double couche interfaciale stabilisante. Enfin, l’association β-lg:GX combine les mécanismes de stabilisation de la protéine, par adsorption interfaciale et de la gomme, par augmentation de la viscosité de la phase continue. / The main objective of this study was to formulate and characterize oil-in-water simple emulsions of pharmaceutical interest stabilized by β-lactoglobulin (β-lg), gum arabic (GA), xanthan gum (XG), and mixtures of β-lg:GA and β-lg:XG. The total biopolymer final concentration in the dispersions was 1 (w/w) % and could be raised to 2.5 (w/w) % if the formulated emulsions were not stable. β-lg:GA mixing was performed at pH 4.2 to allow attractive electrostatic interactions between the two biopolymers and thus the formation of complexes. Two protein:polysaccharide ratios were investigated: 2:1 and 1:2. Conversely, β8lg:XG mixing was performed at pH 7, where both biopolymers are negatively charged, in order to avoid the complex formation, and with a 1:1 ratio. A stability study was conducted for emulsions over a 6-month period. The obtained stabilities could be classified increasingly: GA 2.5 % < β-lg:GA 2.5 % < β-lg 2.5 % < XG 1 % = β-lg:XG 1 %. Several stabilization mechanisms were evidenced by the study of the biopolymer interfacial properties, the study of emulsion rheology and by confocal laser scanning microscopy observations with labeled fluorescent biopolymers. β-lg and GA were both able to adsorb at the interface of oil globule. XG enhanced the continuous phase viscosity. β-lg:GA mixing led to the formation of a stabilizing interfacial double layer. Finally, β-lg:XG association combined the stabilization mechanisms of both biopolymers, respectively: interfacial adsorption and enhancement of the continuous phase viscosity.

O ácido politiofeno acético (PTAA) é um derivado do politiofeno bastante versátil. Sua solubilidade em alguns solventes orgânicos e em soluções básicas aquosas lhe confere extensa processabilidade na forma de filmes finos, característica importante para dispositivos e sensores. Neste trabalho, investigou-se a formação de filmes de PTAA com as técnicas de automontagem e Langmuir-Blodgett (LB). Os filmes automontados foram preparados com dois policátions, hidrocloreto de poli-alilamina (PAH) e cloreto de poli-dialildimetilamônio (PDAC). O crescimento dos filmes depende do pH das soluções e do tipo de policátion, sugerindo dependência do mecanismo de crescimento com as interações específicas polímeropolímero. A conformação do PTAA em filme tem correlação com sua conformação em solução, apontando para um efeito de memória. Por outro lado, a energia de superfície destes filmes não sofre influência da arquitetura nem dessas diferenças conformacionais. Ou seja, embora o volume do filme possa ser distinto, as superfícies possuem propriedades semelhantes. A morfologia dos filmes foi caracterizada a partir de imagens de AFM utilizando conceitos de geometria fractal e estatística. A dimensão fractal dos filmes é semelhante, indicando o mesmo processo de crescimento dos filmes, independentemente das condições da deposição. Os filmes obtidos em pH ácido tinham tamanho de grão e comprimentos de correlação maiores, sugerindo a deposição de cadeias mais enoveladas. Foi possível fabricar filmes autossustentados sem degradação aparente do material a partir de filmes automontados de PAH/PTAA, entrecruzando termicamente os grupos ácido carboxílico e amina. Este é o primeiro relato de filmes deste tipo com derivado do politiofeno. Os filmes LB de PTAA foram obtidos sem adjuvantes, mas as condições de deposição precisam ser aprimoradas. Para explorar a elevada afinidade química entre compostos contendo enxofre e metais pesados, filmes foram utilizados para detecção espectroscópica e eletroquímica. Espectros de fotoluminescência e UV-Vis demonstraram que os metais interagem apenas com os estados excitados resultando na supressão da fluorescência; no entanto, sem especificidade e apenas para longos períodos de exposição. Espectros de FTIR mostraram a presença dos sais na matriz dos filmes. Por sua vez, voltametrias cíclicas permitiram detectar Pb+2 e Hg+2, mas a irreversibilidade dos processos eletroquímicos, causando alargamento dos picos de oxirredução, inviabiliza a detecção simultânea. / Polythiophene acetic acid (PTAA) is a versatile polythiophene derivative. Its solubility in some organic solvents and in basic aqueous solutions makes it attractive for processing thin films, an important feature for the fabrication of devices and sensors. In this thesis, we investigate the formation of PTAA films using the layer-by-layer (LbL) and the Langmuir- Blodgett (LB) techniques. The LbL films were prepared with poly(allylamine hydrochloride) (PAH) and poly(diallydimethylammonium chloride) (PDAC), with film growth depending on the pH of the solutions and type of polycation, thus indicating that the growth mechanism depends on polymer-polymer interactions. The conformation of the PTAA molecules in solid state was correlated with that in solution, in a kind of memory effect. The surface energy of the films was not affected by the film architecture or different conformations. The film morphology was characterized with AFM images using concepts of fractal geometry and statistics. The fractal dimension was similar for all films, and therefore the overall growth obeys the same process regardless of the deposition conditions. Nevertheless, films obtained at acidic pH exhibited larger grain size and correlation lengths than those produced at basic pHs, suggesting deposition of more coiled chains. It was also possible to fabricate selfsustained films without apparent PTAA degradation from the PAH/PTAA LbL films, upon thermal crosslinking of carboxylic acid and amine groups. This is the first report of such films with a polythiophene derivative. LB films of PTAA were obtained without co-spreading materials, but the deposition conditions need to be optimized. To explore the high chemical affinity between PTAA and compounds containing sulfur and heavy metals, some films were used for spectroscopic and electrochemical detection. The UV-Vis and photoluminescence spectra indicated that the metals affect only the excited states, leading to fluorescence quenching after long exposure times and without specificity for the metals. The FTIR spectra pointed to salts in the films. Pb+2 and Hg+2 ions could be detected using cyclic voltammetry, but their simultaneous detection was hampered by the irreversibility of the electrochemical processes which caused broadening of the oxi-reduction peaks.