The prevention and treatment of cancer and infectious diseases requires vaccines that can mediate cytotoxic T lymphocyte-based immunity. A promising strategy is protein subunit vaccines composed of purified protein antigens and immunostimulatory adjuvants, such as Toll-like receptor (TLR) agonists. In this research, we developed two new biodegradable polymeric delivery vehicles for protein antigens and TLR agonists, as model vaccine delivery systems. This work was guided by the central hypothesis that an effective vaccine delivery system would have stimulus-responsive degradation and release, biodegradability into excretable non-acidic degradation products, and the ability to incorporate various TLR-inducing adjuvants. The first vaccine delivery system is a cross-linked polyion complex micelle which efficiently encapsulates proteins, DNA, and RNA. The micelle-based delivery system consists of a block copolymer of poly(ethylene glycol) (PEG) and poly(L-lysine), cross-linked by dithiopyridyl side groups to provide transport stability and intracellular release. The second delivery system consists of solid biodegradable microparticles encapsulating proteins, nucleic acids, and hydrophobic compounds. The microparticles are composed of pH-sensitive polyketals, which are a new family of hydrophobic, linear polymers containing backbone ketal linkages. Polyketals are synthesized via a new polymerization method based on the acetal exchange reaction and degrade into non-acidic, excretable degradation products. In addition, the technique of hydrophobic ion pairing was utilized to enhance the encapsulation of ovalbumin, DNA, and RNA in polyketal microparticles via a single emulsion method. Using in vitro and in vivo immunological models, we demonstrated that the micelle- and polyketal-based vaccine delivery systems enhanced the cross-priming of cytotoxic T lymphocytes. The model vaccines were composed of ovalbumin antigen and various TLR-inducing adjuvants including CpG-DNA, monophosphoryl lipid A, and dsRNA. The results demonstrate that the cross-linked micelles and polyketal microparticles have considerable potential as delivery systems for protein-based vaccines.

Made available in DSpace on 2014-12-17T14:07:07Z (GMT). No. of bitstreams: 1 LuizFMC_TESE.pdf: 3268756 bytes, checksum: e846724b8b5adbbee4ec9a2ecaf76796 (MD5) Previous issue date: 2011-06-20 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The use of raw materials from renewable sources for production of materials has been the subject of several studies and researches, because of its potential to substitute petrochemical-based materials. The addition of natural fibers to polymers represents an alternative in the partial or total replacement of glass fibers in composites. In this work, carnauba leaf fibers were used in the production of biodegradable composites with polyhydroxybutyrate (PHB) matrix. To improve the interfacial properties fiber / matrix were studied four chemical treatments to the fibers..The effect of the different chemical treatments on the morphological, physical, chemical and mechanical properties of the fibers and composites were investigated by scanning electron microscopy (SEM), infrared spectroscopy, X-ray diffraction, tensile and flexural tests, dynamic mechanical analysis (DMA), thermogravimetry (TGA) and diferential scanning calorimetry (DSC). The results of tensile tests indicated an increase in tensile strength of the composites after the chemical treatment of the fibers, with best results for the hydrogen peroxide treated fibers, even though the tensile strength of fibers was slightly reduced. This suggests a better interaction fiber/matrix which was also observed by SEM fractographs. The glass transition temperature (Tg) was reduced for all composites compared to the pure polymer which can be attributed to the absorption of solvents, moisture and other low molecular weight molecules by the fibers / O uso de mat?rias-primas de fontes renov?veis para a produ??o de materiais vem sendo objeto de diversos estudos e pesquisas, devido ao seu potencial na substitui??o de derivados petroqu?micos. A adi??o de fibras vegetais a pol?meros representa uma alternativa na substitui??o parcial ou total de fibras de vidro em comp?sitos. Neste trabalho, fibras da folha de carna?ba (Copernicia prun?fera) foram utilizadas na produ??o de comp?sitos biodegrad?veis com matriz de polihidroxibutirato (PHB). Para melhorar as propriedades interfaciais fibra/matriz foram estudados quatro tratamentos qu?micos, para as fibras. O efeito dos diferentes tratamentos qu?micos nas propriedades morfol?gicas, f?sicas, qu?micas e mec?nicas das fibras e dos comp?sitos foram investigados por microscopia eletr?nica de varredura (MEV), espectroscopia no infravermelho, difra??o de raios-X, ensaios mec?nicos de tra??o e flex?o, an?lise din?mico-mec?nica (DMA) e an?lises t?rmicas por termogravimetria (TG) e calorimetria explorat?ria diferencial (DSC). Os resultados dos ensaios de tra??o dos comp?sitos indicaram um acr?scimo de resist?ncia ? tra??o ap?s modifica??o qu?mica das fibras, sendo o melhor resultado obtido com o tratamento de per?xido de hidrog?nio, mesmo havendo uma pequena redu??o na resist?ncia ? tra??o das fibras tratadas. Isto indica uma melhor intera??o entre as fibras e a matriz polim?rica que foi tamb?m observada nas imagens de microscopia eletr?nica de varredura. A temperatura de transi??o v?trea (Tg) foi reduzida para todos os comp?sitos em rela??o ao pol?mero puro o que foi atribu?do a absor??o de solventes, umidade e outras mol?culas de baixo peso molecular pelas fibras

L'utilisation extensive des combustibles fossiles, l'émission de gaz à effet de serre dans l'atmosphère et les difficultés de recyclage des résidus de consommation incitent au recours accru aux polymères biodégradables. Dans le domaine du génie électrique, de nombreux polymères trouvent des applications dans les systèmes d'isolation des matériels électriques. Ces polymères sont issus du pétrole, peu respectueux de l'environnement et la plupart d'entre eux ne sont pas biodégradables. Dans le but de les remplacer, des polymères biodégradables ont été explorés.Une revue des travaux de recherche sur les polymères biodégradables dans le domaine du génie électrique a été réalisée. Les propriétés thermiques et électriques de polymères biodégradables et conventionnels sont rapportées et comparées.Les polymères biodégradables et / ou biosourcés sélectionnés et mis en œuvre sont le Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), le polycaprolactone (PCL) et l’acide polylactique PLA. Un matériau nanocomposite basé sur PLA a également été préparé. Les propriétés diélectriques pour une large gamme de température et de fréquence ont été mesurées par spectroscopie diélectrique et analysées en s’appuyant sur les propriétés thermiques obtenues par DSC et DMA. La résistivité volumique et la tenue diélectrique ont pu également être mesurées. Ces polyesters biodégradables sont comparés aux polymères conventionnels. / The declining resources of fossil fuels, increase in wide-spread pollution, emission of green-house gases and difficulties in recycling waste materials are pushing biodegradable polymers into prominence. In the domain of electrical engineering, many polymers find applications in various electrical insulation systems. These polymers are petro-based, not eco-friendly and most of them are not biodegradable. With an objective to replace conventional products, biodegradable polymers are explored for their dielectric properties.In this work, a detailed study on the present status in the research work on biodegradable polymers in the electrical engineering domain is presented. Thermal and electrical properties of both biodegradable and classical polymers are compiled and compared.The polymers processed and studied were Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), Polycaprolactone (PCL), Poly(lactic acid) (PLA) and PLA based nanocomposite. Dielectric properties for a wide range of temperature and frequency were measured by dielectric spectroscopy and analyzed with the help of DSC and DMA experiments. Volume resistivity and electrical breakdown were measured on few polymers. These biodegradable polyesters were compared with conventional polymers.

Diariamente são descartados no mundo toneladas de resíduos do processamento de frutas que poderiam ser aproveitados pelo seu elevado poder nutricional e funcional, que acabam sendo desperdiçados e podem gerar sérios problemas ao meio ambiente. Outro descarte inadequado que agrava esse problema ambiental é o de embalagens plásticas, que quando não submetidas ao processo de reciclagem trazem enormes danos. Por esses fatores, esse estudo teve como objetivo o aproveitamento de subprodutos da indústria de alimentos para o desenvolvimento de farinhas funcionais e aproveitamento dos resíduos da indústria de capsulas nutracêuticas de gelatina e óleo de chia como matriz para as embalagens biodegradáveis ativas. A quitosana também foi utilizada como matriz no desenvolvimento de filmes aplicados como embalagens. Primeiramente foram avaliados quatro resíduos obtidos de diferentes frutas: resíduo do processamento de suco de mirtilo (bagaço), resíduo do processamento de azeite de oliva (bagaço), cascas de mamão e abacaxi. As propriedades físico químicas, funcionais e antioxidantes desses resíduos foram analisadas, sendo que no geral todos demonstraram alto teor de fibras dietéticas. Em relação às propriedades funcionais a farinha de mamão se destacou pelos elevados valores de capacidade de retenção de água e óleo, pela alta solubilidade e maiores teores de carotenoides (15,56 ± 0,35 mg/100g). A farinha de mirtilo foi a que apresentou o maior poder antioxidante pelo método DPPH (4,62 ± 0,18 IC50 em mg de farinha) e maior teor de compostos fenólicos (23,59 ± 0.85 mg/g GAE), além disso exibiu alto teor de antocianinas. Devido a estas propriedades, a farinha e o extrato do resíduo de mirtilo foram incorporados à gelatina do resíduo do processamento de cápsulas nutracêuticas de óleo de chia para o desenvolvimento de filmes biodegradáveis ativos. Os filmes foram avaliados em relação as suas propriedades mecânicas, de barreira ao vapor da água e luz UV, capacidade antioxidante e aplicação como embalagem em produtos alimentícios. Os resultados sugeriram que a adição de fibras promoveu uma diminuição da resistência à tração e aumento na permeabilidade ao vapor da água. No entanto, a adição de fibra também proporcionou um aumento significativo na barreira de luz UV a 500 nm, sendo eficaz na redução da oxidação lipídica de óleo de girassol. Os filmes com adição de extrato não exibiram alteração nas propriedades mecânicas ou de barreira em comparação com a formulação controle. Além disso, estes filmes exibiram capacidade antioxidante estável por 28 dias. Filmes desenvolvidos com a farinha de mamão e resíduos de gelatina apresentaram comportamento similar aos filmes com resíduos de mirtilo, já que a farinha de mamão também alterou algumas propriedades originais do filme como as propriedades mecânicas e de barreira, e agregaram poder antioxidante. Com o objetivo de melhorar essas propriedades foram então desenvolvidas micropartículas de farinha de casca de mamão em spray drying utilizando o resíduo de gelatina como material de parede. Os resultados indicaram que as micropartículas de casca de mamão ao serem adicionadas na gelatina originaram uma matriz de filme mais contínua e homogênea com aumento da resistência à tração e do módulo de Young. Os filmes com micropartículas (7,5%), quando aplicados como material de embalagem para banha de porco, foram os mais eficientes como barreiras ativas (maior atividade antioxidante), pois um menor teor de peróxidos, dienos e trienos conjugados foram quantificados na amostra após 22 dias. A farinha de resíduos da produção de azeite de oliva também foi utilizada para o desenvolvimento de filmes biodegradáveis, porém o biopolimero utilizado foi a quitosana. A incorporação de farinha de resíduo de oliva na matriz de quitosana também causou alterações na morfologia, tornando o filme mais heterogêneo e áspero. Por esse motivo foram testadas a adição de micropartículas de farinha de oliva nos filmes. A adição de 10% de micropartículas de oliva melhorou significativamente a resistência à tração dos filmes sem alterar as suas propriedades originais. A farinha e as micropartículas de oliva aumentaram a capacidade antioxidante dos filmes, esse aumento foi proporcional à concentração de farinha ou micropartículas adicionadas ao filme. Os filmes com 30% de farinha ou micropartículas foram eficazes como embalagem protetora contra a oxidação de nozes durante 31 dias. A partir dos resultados obtidos neste trabalho fica evidenciado a viabilidade do uso de resíduos da indústria de alimentos e resíduos da indústria de cápsulas nutracêuticas para o desenvolvimento de filmes e uso como embalagens biodegradáveis em diferentes produtos. / Every day tons of fruit processing residues are discarded worldwide that could be harnessed for their high nutritional and functional power and that end up being wasted and generating problems for the environment. Another inadequate disposal that aggravates this environmental problem is the plastic packaging, which when not subjected to the recycling process bring huge damages. Due to these factors, this study aims at the utilization of by-products of the food industry for the development of active biodegradable packaging. Firstly, four residues obtained from different fruits, processing residue of blueberry juice (bagasse), processing residue of olive oil (bagasse), peels of papaya and pineapple were evaluated. The physicochemical, functional and antioxidant properties of these residues were analyzed, and in general, all showed high total dietary fiber content. In relation to the functional properties, papaya flour was distinguished by high water and oil retention capacity, high solubility and higher carotenoid content (15.56 ± 0.35 mg / 100g). The blueberry flour had the highest antioxidant power by the DPPH method (4.62 ± 0.18 IC50 in mg of flour) and a higher content of phenolic compounds (23.59 ± 0.85 mg / g GAE), in addition, it exhibited a high content of anthocyanins. Due to these properties, the flour and extract of the blueberry residue were incorporated into the gelatin from the processing residue of chia oleuroceutical capsules for the development of active biodegradable films for packaging. The films were evaluated in relation to their mechanical properties, water vapor barrier, and UV light, antioxidant capacity and application as packaging in food products. The results suggested that fiber addition promoted a decrease in tensile strength and an increase in water vapor permeability. However, the addition of fiber also provided a significant increase in the UV light barrier at 500 nm being effective in reducing the lipid oxidation of sunflower oil. Films with added extract showed no change in mechanical or barrier properties compared to the control formulation. In addition, these films exhibited a stable antioxidant capacity for 28 days. Films developed with papaya flour and gelatin residues showed similar behavior to films with blueberry residues since papaya flour also altered some of the original properties of the film as mechanical and barrier properties, and added antioxidant power. In order to improve these properties microparticles of papaya peel flour were then developed in spray drying using the gelatin residue as the wall material. The results indicated that the microparticles of papaya peel, when added to gelatin, gave a more continuous and homogeneous film matrix increasing tensile strength and Young's modulus. Microparticles films (7.5%), when applied as packaging material for lard, were the most efficient as active barriers (higher antioxidant activity) because a lower peroxide content was quantified in the sample after 22 days. The residue flour from olive oil production was also used for the development of biodegradable films, but the biopolymer used was chitosan. The incorporation of olive residue flour in the chitosan matrix also caused changes in the morphology, making the film more heterogeneous and rough. For this reason, the addition of olive flour microparticles in the films was tested. The addition of 10% of olive microparticles significantly improved the tensile strength of films without altering their original properties. The flour and the microparticles of olive increased the antioxidant capacity of the films; this increase was proportional to the concentration of flour or micro added to the film. Films with 30% flour or microparticles were effective as protective packaging against Walnut oxidation for 31 days. From the results obtained in this work, it is evident the viability of the use of residues from the food and waste industry of the nutraceutical capsule industry for the development of films and use as biodegradable packaging in different products.

My thesis is aimed at the possiblities of collecting and utilizing the biodegradable component of municipal waste in the specific environment of České Budějovice. The thesis includes a proposal to construct a municipal biogas plant to decrease the volume of mixed municipal waste. The goal of this part of the thesis is to compare expected costs and income of the project and determine the general economic indicators and evaluate the investment, so that the project can be either fully recommended or rejected.

Orientador: Prof. Dr. Derval dos Santos Rosa / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Ciência e Tecnologia Ambiental, 2017. / Nos dias de hoje, tem sido crescente a preocupação com os impactos ambientais provocados pelo descarte inadequado de sacolas plásticas após seu uso. Em busca de uma solução parcial para o descarte dessas, nos últimos anos vem aumentando o interesse em incrementar e desenvolver materiais biodegradáveis com características que permitam a sua utilização em embalagens e utensílios descartáveis e que contribuam com a sustentabilidade. Esse trabalho teve como objetivo desenvolver filmes poliméricos biodegradáveis, para uso em sacolas descartáveis de supermercado. Os filmes foram preparados utilizando PBAT, PLA e CaCO3, em diferentes composições. Os filmes das composições foram caracterizados por ensaios mecânicos e avaliação da biodegradação. Foram analisados também os desempenhos ambiental e econômico, ao longo do ciclo de vida dos filmes preparados, em comparação com sacolas usuais disponibilizadas nos supermercados (kraft e PEAD). Essa Análise de Ecoeficiência foi realizada segundo as normas ABNT NBR da série ISO 14040, com base em ferramentas de cálculo e bancos de dados de Avaliação de Ciclo de Vida internacionalmente reconhecidos. Os resultados do ensaio mecânico demonstraram que a incorporação de CaCO3 nos filmes diminuiu o alongamento na ruptura e a resistência máxima à tração e aumentou o módulo de Young dos materiais. Todas amostras apresentaram caráter hidrofílico, com ângulos de contato menores que 90º. As amostras com CaCO3 não apresentaram nítidas separação de fases, diferentemente da amostra sem carga, demonstrando que a incorporação do material favoreceu a dispersão e interação de PBAT/PLA. O CaCO3 reduziu e temperatura máxima de degradação das amostras. Com exceção da amostra de papel, todas apresentaram pequenos percentuais de massa sorvida. Após 360 dias do ensaio de biodegradação, os resultados mostraram que não houve uma perda de massa expressiva, no entanto, as amostras já apresentaram uma modificações superficiais, indicando ação de micro-organismos. Na Análise de Ecoeficiência foi possível observar que a incorporação de CaCO3 diminuiu significantemente os impactos econômicos das alternativas em estudo e favoreceu a ecoeficiência dos polímeros biodegradáveis. / Nowadays, there has been growing concern about the environmental impacts caused by the improper disposal of disposable plastic bags after use. In search of a partial solution for their disposal, the interest in improving and developing biodegradable materials of low cost with characteristics that allow its use in disposable containers and utensils that contribute to the sustainability have increased in recent years. This work aimed to develop polymeric biodegradable films for use in disposable supermarket bags. The films were prepared using PBAT, PLA and CaCO3, in different compositions. These films were characterized by mechanical tests and evaluation of biodegradation. There were also analyzed the environmental and economic performance over the life cycle of the films prepared in comparison with the usual alternatives available in supermarkets (paper and PEAD). This Eco-efficiency Analysis was performed according to NBR ISO 14040 standards series, based on calculation internationally recognized tools and databases of Life Cycle Assessment. The results of the mechanical tests demonstrated that the incorporation of CaCO3 in the films decreased the elongation at break and the maximum tensile strength at break of the materials, but increased the Young's modulus. All samples presented a hydrophilic character, with contact angles smaller than 90º. The samples with CaCO3 did not present a clear phase separation, unlike the sample with no load, demonstrating that the incorporation of the material favors the interaction of PBAT with PLA. The CaCO3 reduced the maximum degradation temperature of the samples. With the exception of the paper sample, all presented small percentage of sorbed mass. After 360 days of biodegradation test, the results showed that there was no significant mass loss, however, the samples already presented a superficial modifications, indicating action of microorganisms. In the Eco-efficiency Analysis it was possible to observe that the incorporation of CaCO3 significantly decreased the economic impacts of the alternatives under study and favored the eco-efficiency of the biodegradable polymers.

Abstract Industrial emissions and soil pollution caused by harmful substances attracted an increased public awareness in the 1970s. Ministry of the Environment contributed to the rapid development of environmental legislation. Development of Finnish environmental legislation has also been significantly affected by the membership of the EU has been in 1995. Finnish legislation is largely based on EU legislation, but in some cases it includes even stricter standards and limits than those applied on the EU level. Studies of contaminated soils in Finland began with mapping of landfills in the 1980s. The clearing and renovation project of contaminated soils named SAMASE started in 1988, and approximately 10,400 contaminated areas were surveyed. Currently, the total number of objects has already expanded to about 25,000. This thesis consists of five scientific publications related to contaminated sites. Its summary deals with environmental legislation, treatment methods for soils contaminated with oils and heavy metals, and risk assessment in general. The scientific publications focus on the utilization of two chemical methods, i.e. oil biodegradation of contaminated soil studied, especially by manometric respirometric BOD Oxitop method, and the study of railway ballast using five-step sequential extraction method. The results show that the biodegradability of oil is strongly dependent on the soil matrix and the studied oils (motor and light fuel oils), which are biodegradable well under suitable conditions. When a 6-month long biodegradation study of light fuel contamination in mineral-rich soil without soil conditioning was performed, the final biodegradation degree was surprisingly almost complete (> 90 %), in contrary to the general assumption. Thus, the inherent biodegradability is a cost-efficient and a recommended treatment method for oil contaminated soils, especially in sparsely populated areas. Research of the railway ballast showed that the multi-step sequential extraction will provide valuable information about the effects of environmental circumstances on metals bioavailability or solubility for the purposes of risk assessment. This information is necessary to understand the actual environmental risks of metals in different natural environments, thus contributing to the development of licensing procedure. The results of this thesis also show that licensing related to the restoration of contaminated soils r (authority and control procedures) must be simplified. The authorities should also have sufficient chemical knowledge, since after all, environmental problems are mainly of chemical nature. / Tiivistelmä Huoli ympäristöstä nosti 1970-luvun alussa erilaiset päästöt päivänvaloon, ja haitallisten aineiden aiheuttama maaperän pilaantuminen nousi esille 1980-luvulla. Suomeen vuonna 1983 perustettu ympäristöministeriö on edesauttanut nopeaa ympäristölainsäädännön kehittymistä. Kehitykseen on vaikuttanut merkittävästi myös EU-jäsenyytemme vuodesta 1995 lähtien ja jäsenyyden myötä implementoitu EY:n lainsäädäntö. Joiltain osin säädöksemme ovat jopa tiukempia kuin EU:n vastaavat säännökset. Suomessa pilaantuneiden maiden selvitystyö alkoi kaatopaikkojen kartoituksella 1980-luvulla. Valtioneuvoston v. 1988 antaman selonteon pohjalta käynnistyi saastuneiden maa-alueiden selvitys- ja kunnostusprojekti (SAMASE), jossa kartoitettiin noin 10 400 pilaantuneeksi epäiltyä tai todettua aluetta. Tätä työtä jatketaan edelleen viranomaisten tavanomaisen lupa- ja valvontatyön ohessa. Tällä hetkellä kohteiden kokonaismäärä on noin 25 000. Tämä pilaantuneisiin maihin (PIMA) liittyvä väitöskirjatutkimus koostuu yhteenveto-osasta, jossa käsitellään alan lainsäädäntöä, käsittelymenetelmiä ja riskinarviointia yleisesti sekä viidestä osajulkaisusta, jotka keskittyvät öljyllä pilaantuneiden maiden biohajoavuuteen manometrista respirometrista BOD Oxitop -menetelmää käyttäen ja kaivosteollisuuden sivukiven (raidesepeli) raskasmetallien analytiikkaan sekventiaalista uuttoa hyödyntäen. Tutkimuksen tulokset osoittavat, että öljy biohajoaa maassa sopivissa olosuhteissa hyvin ja luontainen biohajoavuus on täten yksi käyttökelpoinen öljyllä pilaantuneiden maiden puhdistusmenetelmä. Raidesepelitutkimukset osoittivat, että monivaiheinen sekventiaalinen uutto tuo uutta arvokasta tietoa olosuhteiden vaikutuksista metallien biosaatavuudesta/liukoisuudesta niiden riskinarviointia varten. Tämä tieto on välttämätöntä, kun halutaan ymmärtää metallien todelliset ympäristövaikutukset erilaisissa luonnonolosuhteissa ja näin edistää osaltaan lupamenettelyn kehittämistä. Väitöskirjassa todetaan myös, että pilaantuneen maan kunnostuksiin liittyen viranomaisten lupa- ja valvontamenettelyä tulee yksinkertaistaa ja viranomaisilla tulisi olla riittävästi kemian tietämystä ja kemiallista ajattelua, ovathan ympäristöongelmat pääosin luonteeltaan kemiallisia.

Made available in DSpace on 2016-06-02T19:19:57Z (GMT). No. of bitstreams: 1 MISTURA_Daniel_2014.pdf: 2003467 bytes, checksum: 5581d79f572369db3735d9706f07423d (MD5) Previous issue date: 2014-03-10 / Universidade Federal de Sao Carlos / Hydrogels have been widely studied, especially as injectable materials for applications as biomaterials. These hydrogels may possess thermosensitive features near body temperature (LCST Lower Critical Solution Temperature around 37ºC), rapid gelation, carry drugs, cells or cell growth factors. The current challenge is to make these materials biodegradables and mechanical properties optimized for their use in cardiac tissue engineering. The aim of this study was to synthesize hydrogels of poly(N-iropropylacrylamide) (PNIPAAm) from a new class of macromer consisting of 2-hydroxyethyl methacylate (HEMA), poly(L-co-D,L lactic acid) and trimethylene carbonate (PLDLA-co-TMC) in order to give the hydrogel biodegradation characteristics and mechanical properties suitable for future applications in cardiac tissue engineering. Hydrogels were synthesized by free radical polymerization, the macromer having concentrations ranging from 5%, 10% and 15% (w/w) to evaluate the influence in chemical, mechanical and thermal properties. Macroscopic evaluation showed that the hydrogels exhibit characteristics of injectable and thermosensibility. Swelling tests showed swelling hydrogels with absorption of 20, 29 and 63% of water for compositions. Nuclear Magnetic Resonance (NMR 13C e 1H) confirmed the copolymerization of HEMA with PLDLA-co-TMC as well as the copolymerization of hydrogel PNIPAAm-co-AAc-co-HEMAPLDLA-co-TMC. Infrared spectroscopy (FTIR) corroborated the data found in (NMR 13C e 1H). Differential Scanning Calorimetry (DSC) showed a glass transition temperature of 114ºC, 130ºC and 98ºC for hydrogels, near those found in literature, moreover, showed the LCST for samples at 29ºC, 30ºC and 24ºC, temperatures being lower than 37ºC, indicating these hydrogels may be used in the human body. Scanning electron microscopy (SEM) showed hydrogels without interconnected pores. Mechanical tensile tests showed hydrogels with Young s Modulus of 531, 922 and 725 kPa, and over 500% strain in all synthesized compositions. Degradation of materials followed by weight loss and gel permeation chromatography (GPC) demonstrated stability of hydrogel during first 4 weeks and after 10 weeks showed the onset of weight loss. Finally, the biological interactions assays showed the material as cytocompatible and non-toxic to Vero cells. Thus, the synthesized hydrogels are promising for future applications in cells carriers for tissue engineering. / A classe de hidrogéis vem sendo amplamente estudada, principalmente como materiais injetáveis para aplicações como biomateriais. Estes hidrogéis podem possuir características de termo sensibilidade próximos à temperatura corporal (LCST Lower Critical Solution Temperature em torno de 37ºC), solidificarem rapidamente, carregarem fármacos, células ou fatores de crescimento celular. O desafio atual é tornar esses hidrogéis biodegradáveis e com propriedades mecânicas otimizadas à sua utilização. O objetivo deste estudo foi sintetizar hidrogéis de poli(N-isopropilacrilamida) (PNIPAAm) a partir de uma nova classe de macrômero composto por 2-hidróxietil metacrilato (HEMA), poli(L-co-D,L ácido lático) e trimetileno carbonato (PLDLA-co-TMC), a fim de conferir ao hidrogel características de biodegradação e propriedades mecânicas adequadas para futuras aplicações em engenharia tecidual cardíaca. Os hidrogéis foram sintetizados através da polimerização via radical livre, com concentrações do macrômero variando de 5%, 10% e 15% (m/m) visando avaliar a influência nas propriedades químicas, mecânicas e térmicas do hidrogel sintetizado. A avaliação macroscópica mostrou que os hidrogéis apresentam características de materiais injetáveis e termo sensíveis. Os ensaios de intumescimento apontaram hidrogéis com absorção de 20, 29 e 63% de água para as composições estudadas. As análises de ressonância magnética nuclear (RMN 13C e 1H) comprovaram a copolimerização do HEMA com o PLDLA-co-TMC bem como a copolimerização do hidrogel de PNIPAAm-co-AAc-co-HEMAPLDLA-co-TMC. As análises de espectroscopia do infravermelho por transformada de Fourier (FTIR) corroborou os dados encontrados na técnica de RMN 13C e 1H. A técnica de calorimetria exploratória diferencial (DSC) apontou temperaturas de transição vítrea dos hidrogéis 114ºC, 130ºC e 98ºC próximas as encontradas na literatura, além disso, mostrou o comportamento LCST para as amostras nas temperaturas de 29ºC, 30ºC e 24ºC, temperaturas sendo menores que 37ºC, indicando que as mesmas podem ser utilizadas no organismo. A microscopia eletrônica de varredura (MEV) apontou hidrogéis com poros sem interconectividade. Os ensaios mecânicos de tração apontaram hidrogéis com módulo de elasticidade de 531, 922 e 725 kPa e deformações superiores a 500% em todos as composições sintetizadas. A degradação dos materiais foi medida pela perda de massa, bem como por cromatografia de permeação em gel (GPC) apontou estabilidade dos hidrogéis nas primeiras 4 semanas, e após 10 semanas houve o início da perda de massa. Por fim, os ensaios de interação biológica apontaram o material como citocompátivel e não tóxico às células Vero. Sendo assim, os hidrogéis sintetizados são materiais promissores para futuras aplicações em sistemas de carregamento celular para engenharia tecidual.

Submitted by Aelson Maciera (aelsoncm@terra.com.br) on 2017-03-22T19:16:28Z No. of bitstreams: 1 DissTTB.pdf: 2398693 bytes, checksum: 0a0148927746ba0af71705e6c51cb65e (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-03-22T19:21:20Z (GMT) No. of bitstreams: 1 DissTTB.pdf: 2398693 bytes, checksum: 0a0148927746ba0af71705e6c51cb65e (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-03-22T19:21:41Z (GMT) No. of bitstreams: 1 DissTTB.pdf: 2398693 bytes, checksum: 0a0148927746ba0af71705e6c51cb65e (MD5) / Made available in DSpace on 2017-03-22T19:26:28Z (GMT). No. of bitstreams: 1 DissTTB.pdf: 2398693 bytes, checksum: 0a0148927746ba0af71705e6c51cb65e (MD5) Previous issue date: 2016-02-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) / The production of biodegradable films based on renewable low cost resources has increased considerably. The research and development of new materials in this segment make possible to replace, even still partially, the synthetic plastics derived from petrol and to add value to agro-industrial waste and agricultural commodities. The fruit purees (or pulp) represent an alternative for obtaining these low-cost arrays. It can be obtained from the fruit itself or from its processing wastes. Amongst the suited fruits for this purpose is the papaya (Carica papaya), largely available. Brazil is the largest producer of this fruit and, due to its high perishability, is a rich source of waste material for pulp and edible film processing. Although the films prepared from fruit puree lacks in mechanical and permeability properties, such features may be minimized by the addition of nanofillers associated to film forming biopolymers. Thus, the evaluation of papaya puree, in over-ripe stage, as raw material for film processing using a Mathis System (in batch mode) with reinforced nanostructure was the main aim of this study. The films were characterized considering mechanical and thermal properties, permeability, colorimetric and antimicrobial activity. The best results were recorded to formulations in which the pectin was added at 0.5 % (w/v), increasing the maximum fracture strength (σmax), in 12 times when compared to neat puree films (control). The insertion of cellulose nanofibers and chitosan nanoparticles also promoted a σmax increasing, nevertheless in inferior proportion (6.2 and 5 times respectively). The presence of pectin also was positive in reducing the permeability rates (WVP) with values of 77.72 % lower than those measured to the control films. Concerning the colorimetric properties, the films with filler additions (chitosan nanoparticles with glycerol) suffered the greater color changes (ΔE). The addition of chitosan nanoparticles also speed the surface browning index (BI). Again the pectin acted positively in preserving the original color characteristics. The antimicrobial essays indicated that the chitosan in nanoparticle format inside the polymeric matrix did not present any antimicrobial activity. The over-ripe papaya pulp showed to be a raw material suitable for edible biodegradable film processing and the addition of nanofillers and pectin necessary to improve the barrier and mechanical properties and to preserve the original colorimetric features. / A produção de filmes biodegradáveis baseados em recursos renováveis, fazendo uso de matrizes biopoliméricas de baixo custo, vem aumentando consideravelmente. A pesquisa e o desenvolvimento de novos materiais neste segmento possibilitam a substituição, ainda que parcial, dos plásticos sintéticos derivados do petróleo, além de agregar valor a resíduos agroindustriais e commodities agrícolas. Os purês de frutas (ou polpa) representam uma alternativa viável para a obtenção destas matrizes, podendo ser empregados a própria fruta ou rejeitos provenientes de seu processamento. Dentre os frutos adequados para este fim está o mamão papaia (Carica papaya), fartamente disponível no país. O Brasil é seu maior produtor mundial e, devido à sua alta perecividade, é uma fonte rica de rejeitos adequados à produção de polpas e ao processamento de filmes comestíveis. Embora os filmes processados a partir de purê de frutas apresentem limitações mecânicas e de permeabilidade, estas características podem ser minimizadas pela formação de compósitos através da inserção de nanoestruturas de reforço e associação com outros biopolímeros com características filmogênicas. Assim, avaliar o uso de polpas de mamão papaia, em adiantado estado de maturação no processamento de filmes em Sistema Mathis (no modo batelada) e o efeito da inserção de estruturas de reforço, foram os principais objetivos deste trabalho. Os filmes foram caracterizados quanto às suas propriedades mecânicas, térmica, de permeabilidade, colorimétrica e antimicrobiana. Os melhores resultados foram obtidos para as composições em que a pectina foi adiciona em 0,5 % (m/v), elevando a tensão máxima de ruptura (σmax), em 12 vezes quando comparada aos filmes de polpa sem aditivos (controle). A adição de nanofibras de celulose e a nanopartículas de quitosana também melhoraram σmax, mas em valores inferiores (6,2 e 5 vezes respectivamente). A inserção da pectina também foi favorável na redução das taxas de permeabilidade (WVP) com valores 77,72 % inferiores aos filmes controle. Com relação às medidas colorimétricas, as maiores alterações registradas foram para os filmes processados com os reforços (quitosana em conjunto com o glicerol), os quais resultaram em uma maior variação total de cor (ΔE). A presença de nanopartículas de quitosana também acelerou o escurecimento superficial (IE). A adição de pectina nas formulações atuou positivamente na preservação das características colorimétricas iniciais. Os testes antimicrobianos indicaram que a quitosana na forma de nanopartículas inseridas na matriz biopolimérica não apresentou atividade antimicrobiana. A polpa de mamão papaia, na condição sobremadura, mostrou ser uma matéria-prima adequada ao processamento de filmes comestíveis biodegradáveis e a adição de nanoreforços e de pectina necessárias para a melhoria das propriedades mecânicas e de barreira e para a preservação das características colorimétricas iniciais dos filmes.

A l’exception du chapitre bibliographique, cette thèse a été rédigée sous forme d’articles avec des résumés et des discussions tout en comparant les résultats obtenus à d’autres résultats de la littérature dans la même thématique de recherche. Ce travail s’organise en trois axes de recherche : la synthèse organique et la chimie des polymères, la physicochimie de la surface et l’étude de la réponse biologique et de la dégradation des polymères. La problématique de ce sujet de thèse s’articule autour de la resténose intra-stent qui représente la complication majeure de l’angioplastie par pose de stent dans les artères sténosées. Les stents actifs restent la solution actuellement utilisée pour le traitement de la resténose. Ce sont des stents métalliques recouverts d’un polymère qui comporte une substance bioactive généralement un antiprolifératif. Le rôle du polymère est de créer une barrière protectrice entre le métal et la paroi artérielle. Cette barrière doit améliorer la rugosité et la composition chimique du stent métallique, réparer l’endothélium par la prolifération des cellules endothéliales et inhiber la prolifération et la migration des cellules musculaires lisses qui sont responsables d’une façon directe de la reformation de la plaque d’athérome. Les propriétés de surface du polymère lui confèrent un fort pouvoir d’adhérence au métal et de biocompatibilité vis-à-vis de la paroi artérielle. Les interactions créées entre le revêtement polymère et les cellules vasculaires sont modulées par les propriétés physicochimiques de la surface. C’est dans cette optique que mon sujet de thèse est organisé en deux thématiques. / With the exception of bibliographic chapter, this thesis was written in the format of collection of articles with abstracts and discussions while comparing the results with other’s in the literature in the same research theme. This work is organized in three tasks: organic synthesis and stereochemistry of polymers, surface physicochemical properties and biological response and degradation study of polymers. The issue of this thesis is based on in-stent restenosis which represents the major complications of angioplasty with stent placement. Drug-eluting stents are currently the solution used for the restenosis treatment. These are metal stents coated with a polymer having a bioactive substance which is generally an antiproliferative agent. The polymer role is to create a protective barrier between the metal and the arterial wall. This barrier must improve the roughness and the chemical composition of the metallic stent, repair the endothelium by the proliferation of endothelial cells and inhibit the proliferation and the migration of smooth muscle cells which are responsible to the reformation of atheroma plaque. The surface properties confer to polymer a strong adhesiveness to the metal and biocompatibility vis-a-vis of the arterial wall. Interaction created between the polymer coating and vascular cells are modulated by the physicochemical properties of the surface. It is in this context that my thesis is organized into two themes.The first aim of my thesis is to develop a series of amorphous polymers and study their physicochemical (wettability, roughness ...) and biological properties (adhesion, cell behavior and proliferation) and then correlate these properties to choose the promising coating coronary stent. A degradation study was also conducted on elaborate systems. The second is dedicated to chemical synthesis and stereochemistry of polymers. Indeed, new optically active monomers and the corresponding stereopolyesters were synthesized and characterized in order to compare their physicochemical properties with those of amorphous polyesters studied as a coating of the stent and enhance the biomaterials field.