Neste trabalho, ingredientes naturais antimicrobianos foram adicionados em filme biodegradável (biofilme) à base de fécula de mandioca tendo como plastificantes sacarose e açúcar invertido. A seleção dos ingredientes antimicrobianos (cravo em pó, canela em pó, pimenta vermelha em pó, óleo essencial de laranja, café em pó, mel e extrato de própolis) foi conduzida por meio de um delineamento experimental (fatorial fracionado 27-3) e os biofilmes foram analisados quanto às suas propriedades de barreira (permeabilidade ao vapor de água e taxa de permeabilidade ao vapor de água) e propriedades mecânicas (resistência máxima à tração e porcentagem de alongamento na ruptura). Os biofilmes apresentaram valores inferiores aos apresentados pelo biofilme controle quanto às propriedades mecânicas. Em geral, a taxa de permeabilidade ao vapor de água nos biofilmes antimicrobianos manteve-se estatisticamente igual ao do controle. Na segunda etapa do trabalho, a otimização dos ingredientes selecionados foi realizada através de delineamento experimental, com somente adição de cravo e canela em pó, que apresentaram resultados mais promissores na etapa anterior. Foi constatado que a adição de cravo e canela em pó alterou as propriedades mecânicas, porém as alterações foram menos intensas com a adição da canela em pó do que com o cravo em pó, o que pode ser justificado pela diferença de granulometria entre eles. A taxa de permeabilidade diminuiu até certa concentração dos ingredientes (0,34% para a canela em pó e 0,20% para o cravo em pó). O efeito antimicrobiano dos biofilmes foi investigado como embalagem de fatias de pão tipo forma e foi constatado que a atividade de água dos biofilmes aumentou após 7 dias de contato. É provável que os biofilmes tenham se tornado meios propícios para o desenvolvimento de bolores e leveduras visto que estes microrganismos cresceram de forma similar ou mais intensa nas fatias de pão na presença do que na ausência dos biofilmes. A partir dos resultados obtidos, não é possível avaliar de forma clara, o efeito antimicrobiano dos ingredientes incorporados na matriz dos biofilmes contra o crescimento de bolores e leveduras em fatias de pão tipo forma. / In this work, natural antimicrobial ingredients were added to biodegradable film (biofilm) based on cassava starch with sucrose and inverted sugar as plasticizers. The selection of the antimicrobial ingredients (clove powder, cinnamon powder, red pepper powder, orange essencial oil, coffee powder, honey and propolis extract) was carried out applying an experimental design (incomplete factorial 27-3) and the barrier properties (water vapour permeability and water vapour permeability rate) and mechanical properties (tensile strength and elongation at break) of the biofilms were determined. The biofilms presented lower data regarding mechanical properties when compared to biofilm control. In general, the water vapour permeability rate of the antimicrobial biofilms was statistically equal to the control. In the second phase of the work, the optimization of the selected ingredients was carried out applying an experimental design, with the addition of only clove and cinnamon powder due to the fact that they showed the most promissing results at the previous phase. The addition of clove and cinnamon powder modified the mechanical properties but the modifications resulted by the addition of cinnamon powder were less intense tha n the ones resulted by the addition of clove powder, which can be justified by the particle size differences between them. The water vapour permeability rate decreased by specific ingredients concentration (0.34% for the cinnamon in powder and 0.20% for the clove in powder). The biofilms antimicrobial effect was investigated as packaging of pan bread slices and it was verified that the biofilms water activity increased after 7 days of contact. Probably, the biofilms became suitable substrates for yeast and mold development due to the fact that these microorganisms grew equally or more intensely in the pan bread slices when the biofilms were present in comparison to the cases of its absence. According to the results, it is not possible to evaluate clearly the antimicrobial effect of the added ingredients to the biofilm matrix against yeast and mold development in pan bread slices.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O mamÃo (Carica papaya L.) à um fruto climatÃrico, apresenta altas taxas de transpiraÃÃo e, devido ao intenso metabolismo durante o amadurecimento, senesce rapidamente, dificultando o armazenamento, por perÃodos prolongados e, consequentemente gerando altos Ãndices de perdas pÃs-colheita, as quais podem ser agravadas pela aÃÃo do Colletotrichum gloeosporioides. Na perspectiva de estender o tempo de vida Ãtil do mamÃo ÂGolden este estudo objetivou desenvolver um revestimento usando uma combinaÃÃo de concentrado protÃico de soro de leite (CPSL), Ãleo essencial de erva doce (OED), cloreto de cÃlcio (CC) e glicerol (G).Foram realizadas avaliaÃÃes in vitro do efeito de diferentes concentraÃÃes de OED na reduÃÃo do crescimento micelial de C. gloesporioides, assim como foram testados in vitro a capacidade fungitÃxica do OED. Utilizando as duas concentraÃÃes mais eficientes do OED juntamente com diferentes concentraÃÃes de CPSL (10, 12, 14%), CC (1%) e G (5%), foram formulados nove revestimentos, os quais tiveram sua estabilidade avaliada por meio das anÃlises de Ãngulo de contato, diÃmetro mÃdio das partÃculas, potencial zeta e microscopia de varredura. De posse dos revestimentos mais promissores, foram iniciados trÃs experimentos em paralelo. No primeiro,mamÃes inoculados artificialmente com C. gloesporiodes foram submetidos aos revestimentos,para avaliaÃÃo da incidÃncia e severidade do patÃgeno. No segundo e terceiro experimentos, mamÃes sadios foram revestidos e submetidos à anÃlise de sobrevivÃncia e da qualidade, respectivamente. Os testes in vitro demonstraram um potencial positivo na utilizaÃÃo do Ãleo de erva doce no desenvolvimento micelial do fungo C. gloesporioides, com concentraÃÃo mÃnima inibitÃria (CMI) e concentraÃÃo mÃnima fungicida de 2000ppm. O conjunto de analises utilizado para avaliar a estabilidade dos revestimentos formulados indicou que, aqueles contendo menor percentual de CPSL (10%)e maiores concentraÃÃes de OED (0,2% e 0,4%) proporcionaram, a formaÃÃo de revestimentos mais estÃveis. No experimento utilizando mamÃes inoculados com C. gloeosporioides, foi possÃvel observar menor incidÃncia e severidade da doenÃa nos pontos nÃo inoculados dos mamÃes revestidos. Os revestimentos testados na anÃlise de sobrevivÃncia foram capazes de retardar o processo de maturaÃÃo dos mamÃes, sendo o tratamento composto por: 10% de CPSL, 0,4% de OED, 1% de CC e 5% de G o mais eficiente no controle da incidÃncia de C. gloeosporioides e na extensÃo da vida pÃs-colheita destes frutos. / Papaya (Carica papaya L.) is a climacteric fruit, has high transpiration rates and due to the intense metabolism during ripening, senesce quickly, making it difficult to store for long periods and consequently generating high rates of post harvest losses, which may be aggravated by the action of Colletotrichum gloeosporioides. In view of extending the useful life of the papaya'Golden' this study aimed to develop a coating using a combination of protein whey concentrate (WPC), essential oil of fennel (OED), calcium chloride (CC) and glycerol (G). Evaluations were carried out in vitro effect of different concentrations of OED reduction in mycelial growth of C. gloesporioides as were tested in vitro fungitoxic capacity of the O ED. Using the two most efficient concentrations of OED togethe r with different concentrations of WPC (10, 12, 14%), DC (1%) and G (5%) were formulated nine coatings, which have had their stability evaluated using the analysis contact angle, average particle diameter, zeta potential and microscopy. Possession of the most promising coatings were started three experiments in parallel. In the first, papayas artificially inoculated with C. gloesporiodes were submitted to coatings, to assess the incidence and severity of the pathogen. The second and third experiments, sound papayas were coated and subjected to analysis of survival and quality respectively. In vitro tests showed a positive potential in use of the fennel oil on mycelial growth of the fungus C. gloesporioides with minimal inhibitory concentration (MIC) and mini mum fungicidal concentration of 2000 ppm. The set of analyzes used to assess the stability of the formulated coatings indicated that those containing a lower percentage of WPC (10%) and the OED higher concentrations (0.2% and 0.4%) provided the formation of more stable coatings. In the experiment using papayas inoculated with C. gloeosporioides, we observed a lower incidence and severity of disease in non - inoculated points of the coated papayas Coatings tested in survival analysis were able to slow the ripening process of papayas, and the treatment consists of: 10% of CPSL, 0.4% O ED, 1% and 5% CC G was the most effective in controlling the incidence of C. gloeosporioides and the extension of postharvest life of these fruits

A preocupação com o meio ambiente tem gerado discussões em torno da sustentabilidade ambiental. Neste ponto, o design pode contribuir com o desenvolvimento de produtos voltados para a redução de impactos ambientais. Visando a colaboração do design com a preservação do meio ambiente, uma possível alternativa encontra- se na aplicação de materiais biodegradáveis em soluções de design. Dessa forma, esta pesquisa tem como objetivo geral investigar a viabilidade de aplicação dos compósitos biodegradáveis à base de biopolímero poli(butileno adipato-co-tereftalato e poli(ácido lático) com fibras de curauá no design de produto. Para isso, inicialmente foi realizado um mapeamento em torno de artigos que visam o desenvolvimento e a caracterização de compósitos biodegradáveis que utilizam fibras vegetais brasileiras como reforço. Este levantamento resultou em um panorama de pesquisas da área, os tipos de materiais que compõe os compósitos biodegradáveis, os tratamentos utilizados nas fibras e os aditivos na matriz, as formas de processamento e as propriedades mecânicas. A partir destas propriedades foi possível verificar os materiais que possuem propriedades semelhantes, e assim, averiguar em que tipo de produtos são empregados estes materiais, para posteriormente, examinar o emprego de compósitos biodegradáveis nestas aplicações. Desse modo, foi possível realizar o prognóstico de aplicações para os compósitos biodegradáveis. Na sequência do trabalho, realizou-se um estudo de caso em torno dos compósitos biodegradáveis, a fim de verificar a viabilidade de aplicação destes materiais. Utilizou-se a técnica de entrevistas semi estruturadas com designers de produto, que resultou na relação de atributos tangíveis, intangíveis com possíveis aplicações para os referidos compósitos. / Concern for the environment has generated discussions on environmental sustainability. At this poin, the design can contribute to the development of products designed to reduce environmental impacts. Aiming at the design collaboration with the preservation of the environment, a possible alternative is the use of biodegradable materials in design solutions. Thus, this research aims at investigating the feasibility of application of composite biopolymer based biodegradable poly (butylene adipate -co- terephthalate and poly (lactic acid) fiber curauá in product design. Initially we conducted a mapping around articles aimed at the development and characterization of biodegradable composites using Brazilian vegetable fibers as reinforcement. This survey resulted in an overview of research in the area, the types of materials that make up the biodegradable composites, the treatments used in the fibers and additives in matrix, forms processing and mechanical properties. based on these properties was possible to verify that the materials have similar properties, and thus determine what kind of products are used these materials to further examine the use of biodegradable composites in these applications. Thus, it was possible to perform the prediction of applications for biodegradable composites, following the study, there was a case study around biodegradable composites in order to verify the feasibility of these materials. to do this, we used the technique of semi-structured interviews with product designers, which resulted in the ratio of tangible attributes, intangible assets with potential applications for these composites.

Submitted by Raquel Vergara Gondran (raquelvergara38@yahoo.com.br) on 2016-04-27T01:25:16Z No. of bitstreams: 1 ariane schmidt furtado - produo avaliao e aplicao de um extrato proteico proveniente da microalga spirulina platensis.pdf: 2077158 bytes, checksum: 505e9db59057e32477cace2f937214ac (MD5) / Approved for entry into archive by Gilmar Barros (gilmargomesdebarros@gmail.com) on 2016-04-29T21:21:35Z (GMT) No. of bitstreams: 1 ariane schmidt furtado - produo avaliao e aplicao de um extrato proteico proveniente da microalga spirulina platensis.pdf: 2077158 bytes, checksum: 505e9db59057e32477cace2f937214ac (MD5) / Made available in DSpace on 2016-04-29T21:21:35Z (GMT). No. of bitstreams: 1 ariane schmidt furtado - produo avaliao e aplicao de um extrato proteico proveniente da microalga spirulina platensis.pdf: 2077158 bytes, checksum: 505e9db59057e32477cace2f937214ac (MD5) Previous issue date: 2013 / A microalga Spirulina platensis é uma fonte renovável e não-convencional de proteínas que pode ser aplicada na confecção de filmes biopoliméricos, para serem utilizados na produção de embalagens biodegradáveis, minimizando agressões ao meio ambiente e agregando valor a esta matéria-prima antes utilizada principalmente como ração animal. Com base nisso, este trabalho teve por objetivo a produção, avaliação e aplicação de filmes nanocompósitos obtidos a partir de extrato proteico proveniente da microalga Spirulina platensis. Para tanto, inicialmente foi obtido um extrato proteico da Spirulina (EPS) através de extração química por variação do pH. Este extrato, contendo 64 % de proteína (base seca), foi avaliado quanto à sua composição de aminoácidos e caracterizado quanto à sua funcionalidade (solubilidade; capacidade de retenção de água e óleo; capacidade espumante; estabilidade espumante). Posteriormente, o EPS foi utilizado como matéria-prima para obtenção de filmes proteicos nanocompósitos com adição de nanoargila montmorilonita (MMT). A obtenção dos mesmos foi realizada através do preparo de soluções filmogênicas, seguido da técnica de casting e secagem a 40 °C (±2 °C) em estufa com circulação de ar. Foram utilizados dois tipos de planejamento: um para avaliar as variáveis do processo de obtenção dos filmes (Planejamento Fatorial Fracionário) e outro para determinar as melhores condições de obtenção dos filmes (Delineamento Central Composto Rotacional - DCCR). Os filmes foram avaliados quanto às suas propriedades mecânicas (resistência à tração - RT, e elongação) e ópticas (diferença de cor - ΔE* e opacidade – Y %), espessura, permeabilidade ao vapor de água (PVA), solubilidade em água e umidade (U %). Com base na menor PVA (8,51 g.mm.(kPa. d. m2 ) -1 ) e umidade (12,7 %), o filme escolhido para ser utilizado como parte de um sistema de embalagem individual para massa de pizza teve a seguinte formulação: 4,5 g de EPS, 1,35 g de glicerol e 0,1 g de MMT em 150 mL de água destilada, pH 11,0 e temperatura final do processo de 75 °C (ensaio 5 do DCCR). Ele foi um dos filmes menos espesso (0,092 mm), elástico (elongação de 16 %), escuro e opaco, apresentou RT de 2,49 MPa (dentre as maiores) e foi o mais solúvel dos filmes, com solubilidade de 69,2 %. Foi avaliada a eficiência deste filme como parte do sistema de embalagem através de análises de perda de massa, textura e contagem de bolores e leveduras nas pizzas. Verificou-se que o mesmo não foi eficiente em conservar as massas de pizza, pois permitiu uma grande perda de massa e alterações inaceitáveis na textura, indicando assim uma alta permeabilidade ao vapor de água, o que também é indesejável. De modo geral, concluiu-se que é possível obter um extrato proteico a partir de Spirulina e aplicá-lo como matéria-prima de filmes proteicos nanocompósito com adição de MMT. No entanto, o filme em questão não foi eficiente quando aplicado como embalagem para conservação de massa de pizza. / Microalgae Spirulina platensis are a renewable, unconventional source of protein which can generate biopolymeric films to be applied on the production of biodegradable packaging, minimizing environmental damage and adding economic value to a raw material mostly used as animal feed. Based on that, the purpose of this study was to product, evaluate and test an application of nanocomposite films obtained from protein concentrate of Spirulina platensis microalgae. In that regard, a Spirulina-based protein concentrate (SPC) was developed by chemical extraction through pH-shift process. This concentrate contains 64 % protein (dry base) and the tests analyzed its amino acid composition and its functionality (solubility; water/oil absorption capability; capacity of producing foam; foam stability). Afterwards, the SPC was used as raw material to produce nanocomposite protein films with addition of montmorillonite nanoclay (MMT). The production was done using filmogenic solutions, followed by casting and drying at 40 °C (±2 °C) in incubator with blower. Two types of planning were used: Fractional Factorial Planning (FFP), to evaluate film-producing process variables, and Central Composite Rotational Delineation (CCRD), to settle the best conditions to make the films. Those films had their mechanical (tensile strength – TS and elongation) and optical (color deviation and opacity) properties analyzed, as well as thickness, water steam permeability, solubility in water and humidity. Based on the smaller permeability (8.51 g.mm.(kPa. d. m2 ) -1 ) and humidity (12.7 %), the film chosen for use as part of a system of individual packing for pizza dough had the following formulation: 4.5 g of SPC, 1.35 g of glycerol and 0.1 g of MMT in 150 mL of distilled water, pH 11.0 and final process temperature of 75 ºC (CCRD sample no. 5). That film was one of the thinnest (0.092 mm) and less elastic (16 % of elongation), dark and opaque, as well as it had a TS of 2.49 MPa (one of the highest) and was the most soluble (69.2 % of solubility). Its efficiency as part of a packaging system was evaluated by texture, mass losses and mold and yeast count. The tests showed that the film is inefficient to preserve pizza dough, since it was unable to avoid large mass losses and inacceptable texture modifications, indicating moreover high permeability to water steam, which is also undesirable. In conclusion, it is possible to obtain a Spirulina-based protein concentrate and use it to make nanocomposite protein films with addition of MMT. Nevertheless, the film tested in this study is inefficient as part of a packaging system for pizza dough.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-06-21T17:20:01Z No. of bitstreams: 1 2015 - Vinicius Olivieri Rodrigues Gomes.pdf: 8391173 bytes, checksum: b3790798dbf591af7fcc8e63ad01c306 (MD5) / Made available in DSpace on 2017-06-21T17:20:01Z (GMT). No. of bitstreams: 1 2015 - Vinicius Olivieri Rodrigues Gomes.pdf: 8391173 bytes, checksum: b3790798dbf591af7fcc8e63ad01c306 (MD5) Previous issue date: 2015-07-22 / The need of producing polymeric artifacts increasingly powerful and versatile but which have increasingly lower biodegradation times motivates the scientific community to seek combinations of natural and synthetic polymers in order to meet both aspects. The manufacture of the blend LDPE/TPS Starch / Chitosan aims to go against that objective. The biodegradation occurs mostly in the soil. Trying to understand the dynamics of the biodegradation process in soil, this paper monitored the effects caused by deposition of the blend, analyzing different parameters, such as organic carbon, organic matter and microbial carbon, indicating levels of soil quality.The blends were prepared with different concentrations of chitosan, with values set to 0, 7, 5 and 15% of total mass and buried in pure soil and soil treated with humus. The analysis periods were 10, 40, 70, 100 and 130 days, with samples being exposed to the environment. Infrared analysis were performed using Fourier transform, X-ray diffraction, scanning electron microscopy with spectroscopy dispersive energy before and after biodegradation mass loss, after the biodegradation process of the blends. Organic carbon, organic matter, microbial carbon, pH and moisture in the soil.The results obtained after analysis in blend showed that with the passage of time, the biodegradation process happened, considering that carbon levels dropped considerably and oxygen were increased in accordance with the EDS analysis. The FTIR analysis confirmed this fact by showing that there was an intese oxidative process, especially in the initial 70 days in all samples. The X-RD analysis showed that there was a variationin crystallinity, but always with a decrease of this paramenter. The weight loss was also significant and progressive in all samples. Soil results showed that the same is resilient and can recover its characteristics during the biodegradation process. At the beginning of the experiment, especially in the first 40 ays, all evaluated paramenters declined considerably, but returned to baseline levels and maintained these values by the end of the experiment. Experimental design was made and it showed that none of the dependent variables influenced the biodegradion process. / A necessidade de produzir artefatos polim?ricos cada vez mais vers?teis e ?performantes? e que apresentem caracter?sticas de biodegrada??o cada vez mais acentuadas tem motivado a comunidade cient?fica a buscar combina??es entre pol?meros sint?ticos e naturais com o objetivo de atender esses aspectos. O desenvolvimento de blendas de polietileno de baixa densidade/amido termopl?stico/quitosana (PEBD/TPS/Q) e de amido termopl?stico/quitosana (TPS/Q) visou ir de encontro a tal objetivo, procurando entender a din?mica do processo biodegradativo no solo. O presente trabalho acompanhou os efeitos causados pela deposi??o dessas blendas, analisando diferentes par?metros, como carbono org?nico total, massa org?nica total e carbono de biomassa microbiana, que indicam n?veis de qualidade do solo, al?m da perda de massa ap?s cada per?odo de biodegrada??o. As blendas de PEBD/TPS/Q e TPS/Q foram preparadas com diferentes concentra??es de quitosana, com valores definidos em 0, 7,5 e 15% da massa total e enterradas em solo puro e solo tratado com h?mus. Os per?odos de an?lise de biodegrada??o foram de 10, 40, 70, 100 e 130 dias, com as amostras sendo expostas ao ambiente. As blendas foram analisadas por espectroscopia de infravermelho com transformada de Fourier (FTIR), difra??o de raios-X (DRX), microscopia eletr?nica de varredura com espectroscopia de energia dispersiva (MEV/EDS), e quanto a perda de massa, antes e ap?s o processo de biodegrada??o. Tamb?m foram realizadas an?lises de carbono org?nico total, massa org?nica total, concentra??o de carbono de biomassa microbiana, pH e umidade dos solos utilizados. Os resultados comprovaram o processo biodegradativo das blendas com o passar do tempo, tendo em vista a diminui??o dos n?veis de carbono e aumento consider?vel dos n?veis de oxig?nio das blendas de PEBD/TPS/Q, de acordo com as an?lises de FTIR e EDS, e total biodegrada??o das blendas de TPS/Q. As bandas de FTIR comprovaram a ocorr?ncia do processo oxidativo, principalmente nos 70 dias iniciais, nas amostras de PEBD/TPS/Q. As an?lises de DRX mostraram que houve uma varia??o da cristalinidade, com a tend?ncia de diminui??o deste par?metro. A perda de massa tamb?m foi consider?vel e progressiva para todas as amostras. Os resultados de an?lise das amostras de solo mostraram o poder de recupera??o da atividade microbiana dos mesmos (resili?ncia) durante o processo biodegradativo. No per?odo inicial do experimento, em especial nos primeiros 40 dias, todos os par?metros avaliados sofreram decaimento de seus valores, por?m retornaram aos patamares iniciais e mantiveram esses valores at? o final do experimento. O planejamento experimental realizado mostrou que nenhuma das vari?veis independentes influenciou no processo de bioatividade do solo.

Resíduos lignocelulósicos são substratos proeminentes para a produção sustentável de polihidroxialcanoatos (PHAs) e etanol. A xilose é um dos principais componentes da lignocelulose, mas o aproveitamento eficiente desse açúcar ainda representa uma barreira técnica. O objetivo desse trabalho foi obter linhagens bacterianas mais eficientes no consumo desse açúcar. Foi introduzido maior número de cópias dos genes do catabolismo (xylAB) e transporte (xylFGH) de xilose, nas linhagens Escherichia coli KO11, produtora de etanol, e Burkholderia sacchari LFM 101, produtora de poli-3-hidroxibutirato (PHB). Os recombinantes foram avaliados quanto ao consumo de xilose e produção na presença e ausência de glicose. Para B. sacchari LFM 101 essa estratégia não incrementou o consumo desse açúcar. Para E. coli KO11 xylAB reduziu o tempo de consumo de xilose e aumentou a produção final de etanol em 30%, mas esse efeito foi prejudicado pela repressão catabólica; enquanto xylFGH foi deletério ao reduzir para quase zero o crescimento e produção de etanol por essa linhagem. / Lignocellulosic residues are remarkable substrates for the sustainable production of polyhydroxyalkanoates (PHAs) and ethanol. Xylose is one of the most important lignocelullose component but its efficient utilization still represents a technical barrier. The aim of this work was to obtain bacterial strains more efficient in the xylose consumption. Multiple copies of the catabolism (xylAB) and transport (xylFGH) genes of xylose were introduced in the ethanol producer Escherichia coli KO11 strain and the poly-3-hydroxybutyrate (PHB) producer Burkholderia sacchari LFM 101. The recombinants strains were evaluated for their production and xylose consumption in the presence and absence of glucose. This strategy did not increase xylose consumption in B. sacchari strains. The xylAB gene improved xylose consumption and increased the ethanol production about 30% in E. coli KO11, but this effect was impaired by catabolite repression; while xylFGH gene was deleterious to reduce the growth and ethanol production by this strain.

O tratamento de pacientes com doenças inflamatórias oculares crônicas frequentemente implica no uso prolongado de drogas anti-inflamatórias sistêmicas como, corticosteroides e outros imunossupressores, podendo acarretar efeitos colaterais importantes. O uso local destas drogas pode contribuir para aumentar seus efeitos desejáveis e reduzir os efeitos colaterais. Implantes intraoculares biodegradáveis são capazes de disponibilizar o fármaco diretamente na cavidade vítrea em doses terapêuticas por período prolongado. O copolímero do ácido lático e glicólico (PLGA) é um clássico exemplo entre os polímeros sintéticos biodegradáveis aplicados em sistemas de liberação de fármacos devido à sua biocompatibilidade e ausência de toxicidade em testes in vivo. A ciclosporina A (CsA) é um imunossupressor largamente usado na clínica médica, e também tem sido empregada no tratamento de várias doenças inflamatórias intraoculares. O objetivo deste estudo foi avaliar a farmacocinética vítrea da CsA, quando aplicada por meio de implante biodegradável de PLGA intravítreo na concentração de 350 µg em olhos de coelhos, assim como avaliar a ocorrência de toxicidade retiniana causada pela presença intraocular do sistema de liberação de fármacos por meio de eletrorretinografia (ERG) e histopatologia. Dos sessenta coelhos que foram utilizados neste estudo, 38 receberam o implante intravítreo de PLGA contendo CsA e 22 somente os veículos. Somente o olho direito dos coelhos foi analisado na pesquisa. O estudo teve duração de oito semanas. Quatro coelhos do grupo CsA e dois do grupo controle foram sacrificados semanalmente para a coleta do vítreo e posterior estudo farmacocinético. Quatro animais de cada grupo foram escolhidos para terem a pressão intraocular aferida semanalmente. Seis coelhos foram submetidos a ERG no início e ao final do estudo, sendo então sacrificados, e os olhos processados para estudos histológicos da retina. O período inferido de permanência da CsA na cavidade vítrea foi de 17 semanas. Nos dois grupos, com e sem CsA, não foram observadas alterações histológicas na retina, entretanto houve importante redução da onda b nas fases escotópicas da ERG no grupo CsA, indicando toxicidade na via dos bastonetes após as oito semanas de seguimento. Em resumo, estes resultados mostraram que a CsA aplicada por meio de implantes oculares de PLGA na dose de 350 µg não causa alterações histológicas da retina, mas provoca um padrão exclusivo de diminuição da onda b. Em estudos futuros, seria interessante avaliar os efeitos de implantes contendo concentrações inferiores a 350 µg de CsA, e também, veículos que permitam que sua liberação seja mais lenta, evitando-se, assim, a toxicidade observada nos ERGs e confirmar sua aplicabilidade clínica como alternativa interessante para o tratamento de doenças oculares inflamatórias crônicas. / Treatment of patients with chronic inflammatory ocular diseases often involves the use of systemic anti-inflammatory drugs such as corticosteroids and other immunosuppressive agents for a long period of time, which may cause significant systemic side effects. Intraocular use of these drugs may help to improve their local beneficial effects and reduce systemic adverse effects. Biodegradable intraocular implants are able to deliver drugs directly into the vitreous cavity in therapeutic doses for an extended period of time. Poly-lactic-co-glycolic acid (PLGA) is a good example of synthetic biodegradable polymers used in ocular drug delivery systems due to its biocompatibility and absence of toxicity. Cyclosporine A (CsA) is a largely used immunossupressor, and it has also been employed for treatment of various intraocular inflammatory diseases. The objective of this work was to evaluate the pharmacokinetics of CsA, when applied in biodegradable PLGA intravitreal implants in rabbit eye and its retina toxicity by electroretinography and histopathology. Right eyes of sixty rabbits were used on this study, 38 received the PLGA implant containing 350 µg of CsA, and 22 the implant without the drug and were followed during 8 weeks. Four animals of CsA group and 2 of control group were sacrificed weekly to have their vitreous samples collected for subsequent pharmacokinetic study. Four animals from each group were chosen to have intraocular pressure measured weekly. Six animals of each group underwent electroretinography tests at baseline and at the end of the study. Then they were sacrificed and had their eyes processed for histological studies of the retina. It was hypothetically calculated that CsA would take 17 weeks to be completely delivery by this system. Histologically the retina did not show alterations in both groups, but there was a significant reduction in the b wave of the scotopic ERG phases in the CsA group indicating toxicity of the rods pathway after 8 weeks of follow-up. In summary, PLGA implants with 350 µg of CsA does not cause retinal histological changes, but decreases b wave amplitude. In future studies it would be interesting to test lower concentrations of CsA using this delivery system to decrease possible toxicity and to guarantee its clinical applicability.

A review of the chemistry of poly(lactic acid) was carried out with a focus on techniques and applications of PLA polymer and copolymers with reference to some of the work that has been accomplished over the last 20 years or so. A review of the characterisation techniques used to analyse PLA polymers and copolymers was also carried out giving reference to the equipment and methods used herein. An investigation into the potential of PLA as the hydrophilic portion of a polymeric surfactant was carried out. To develop PLA based surfactants, the ring opening polymerisation of lactide was carried out in a melt in the presence of a long chain alcohol (C₇ to C₂₀) or diol (C₄ & C₆) to produce AB or ABA type polymers that follow the traditional surfactant template. Stannous octanoate and 4-dimethylaminopyridine were typically used as catalysts due to their high activity and relative cheapness. PLA only shows good hydrophilicity with up to 12 lactic acid units in the chain. Above this the electrostatic interactions between polymer chains reduced water solubility. It was also noted that D,L-lactide produced more water soluble polymers (syndiotactic) than the enantiomerically pure L-lactide (isotactic polymer chains). An investigation of the hydrophobic properties of PLA was carried out to evaluate their usefulness for other biodegradable surfactant applications. To this end an investigation of sugars as the hydrophilic portion of the molecule was carried out. Due to problems with solubilising sugars, they were deemed unsuitable for use as initiatiors within the scope of this research. Choline chloride was then investigated as a potential hydrophilic initiator and indeed has produced some of the most water soluble of PLA polymers. Choline chloride presented several challenges as an initiator, its high melting point resulted in polar solvents such as t-butanol being employed. Alternatively, more success was achieved by preparation of a choline chloride eutectic mixture prior to the polymerisation. It was discovered that a choline chloride/urea eutectic mixture was capable of self initiation, thus required no further addition of catalyst, this result shows a potential step forward in PLA green chemistry. A final investigation into producing surface-active PLA in a one-pot process that required only a hydroxycarboxylate initiator was carried out. The production of PLA sodium or potassium salts was carried out in a melt polymerisation and the results show some promise. Initiators that have been employed include a range of a, b and g-hydroxycarboxylic acids. These work through tautomerisation to the alkoxide, which then initiates a living type polymerisation of lactide to produce surface-active polymers. As well as the synthesis of these polymers some analysis of the physical and aqueous properties of these materials was carried out. PLA sodium salts were shown to have reasonable surfactant ability (~45 mNm⁻¹) and low CMC values of around 5x10⁻⁹ mol cm⁻³. They were also shown to have some properties as emulsifiers, and in some cases showed non-Newtonian fluid behaviour such as shear-thinning (thixotropy) and shear-thickening (dilatant). The thermal characteristics of the polymers such as T[subscript]g and stability were assessed as well as their ability to retain water.

La quantité de déchets augmente depuis plusieurs décénies, issus principalement de l'industrie du plastique. La production cumulée de matières plastiques au cours des dix dernières années est supérieure que pendant le dernier millénaire. Une des solutions pour réduire les impacts écologiques et économiques est de dévelopement de films et enrobages biodégradables et/ou comestibles.L'objectif de cette thèse est d'étudier des films et enrobages comestibles à base d'amidon. Quinze types de solutions filmogènes ont été formulés: 3 types d’amidons, amidon + protéines, amidon + huile de colza, amidon + plastifiant. Afin de mieux comprendre le rôle des constituants et les interactions mises en jeu, les propriétés physico-chimiques et structurales des films ont été réalisées. Enfin, les films présentant les meilleurs compromis ont été appliqués sur des prunes.L’étude physico-chimique des films à base d’amidon de maïs, de pommes de terre et de de blé ont permis de retenir l’amidon de blé pour les études suivantes. Une quantité de plastifiant de 50% (par rapport à la masse sèche de biopolymère) a été sélectionnée car elle permet d'obtenir des films souples et resistants sans blanchiment. Afin d'améliorer l'efficacité barrière à l'humidité, de l'huile de colza a été ajoutée par laminage sur le film d’amidon. Les observations de la microstructure montrent une dispersion de gouttelettes d’huile dans la matrice à la place d’une structure multicouche amidon-huile-amidon. Diverses proportions amidon/protéine ont été testées pour améliorer les propriétés fonctionnelles des films. Plus la teneur en protéines est élevée, meilleure est l'efficacité barrière à la vapeur d'eau, à l'oxygène ou aux arômes. En effet, les films sont plus denses et homogènes en présence des protéines. A partir de la meilleure compréhension du rôle de la composition et de la structure sur les performances des films, plusieurs formulations ont été testées comme enrobage ou film sur des prunes fraîches. L’analyse thermographique a été utilisée pour étudier le comportement des prunes pendant le stockage, l’enrobage/film composé de l’amidon enrobage s’est avéré efficace pour retarder la dégradation des fruits. / The amount of waste increased annually, mainly from plastic industry. Plastic materials were more produced during the only last ten years than during the last millennium. A potential solution of the ecological and economic problems can be biodegradable or edible films and coatings. The goal of this thesis was to study edible films and coatings based on starch. Fifteen types of film-forming solutions were made: 3 types of starch, starch + different amounts of plasticizer, starch + proteins, starch + oil. To better understanding the interaction between film components, physical, chemical and functional tests were done. Finnaly, validation on real foods (plums) as coatings and films helped to improved edible barrier films for fruit and vegetable preservation.Preliminary physico-chemical studies of corn, potato and wheat starch film properties allowed choosing the wheat starch-based films further experiments. Then, a 50% amount of plasticizer related to dry biopolymer weight was selected aiming to obtain films being not too rigid, that did not break and without blooming. To prove the barrier moisture efficacy, rapeseed oil was added as multilayers films. Microstructure observations displayed that oil was dispersed as droplets instead of layer, thus emulsion-based films were obtained instead of multilayer starch-oil-starch films. Various ratios of starch/protein were assessed to improve functional properties of films. The more the protein content was, the better the barrier efficiency against water vapour, oxygen or aroma were. Indeed, higher protein content films were more dense and homogeneous. From these data obtained on films, and the better understanding how composition and structure affect film performances, several recipes were tested as coatings or films for wrapping fresh plums. Thermographic analysis was used to study the plums behavior during storage, and starch coating was efficient to delay fruit degradation. / Z każdym rokiem wzrasta liczba produkowanych odpadów, w szczególmości tych z plastiku. W ciągu pierwszych dziesięciu lat wyprodukowano więcej tworzyw sztucznych niż w przeciągu całego ubiegłego tysiąclecia. Rozwiązaniem tych ekologicznych i ekonomicznych problemów mogą okazać się filmy i powłoki do żywności. Celem tej pracy były studia nad jadalnymi filmami i powłokami na bazie skrobi. Piętnaście rodzajów roztworów powłokotwórczych zostało wytworzonych: z 3 typów skrobi, skrobia + różne stężenia plastyfikatora, skrobia + białka, skrobia + olej. W celu lepszego zrozumienia interakcji pomiędzy komponentami filmu właściwości fizyczne, chemiczne i funkcjonalne zostały zmierzone. W ostatnim etapie walidacja na prawdziwej żywności (powlekanie i pakowanie śliwek) pomogła w udowodnieniu istnienia właściwości barierowych owoców i warzyw podczas przechowywania.Próbne testy fizyko-chemiczne skrobi kukurydzianej, ziemniaczanej i pszenicznej pomogły w wyborze skrobi otrzymywanej z pszenicy do dalszych badań. Następnie wybrano zawartość plastyfikatora. 50% glicerolu względem suchej masy substancji powłokotwórczej nie powodowało twardości i pękania filmów ani też tzw. efektu kwitnienia (intensywnie żółty/ pomarańczowy kolor filmów). W celu poprawy właściwości barierowych olej rzepakowy został dodany. Zdjęcia mikroskopowe obrazują zawieszone krople oleju w matrycy jako emulsja zamiast dodatkowej warstwy, której oczekiwano. Do skrobi zostały dodane również białka serwatkowe w kilku proporcjach. Im więcej białek jest w stosunku procentowym skrobia/proteiny tyym lepsze są właściwości barierowe dla pary wodnej, tlenu i aromatów. Dodatkowo filmy zawierające więcej protein w stosunku procentowym są bardziej gęste i jednolite. Uzyskane informacje pozwoliły na lepsze zrozumienie wpływu kompozycji i struktury filmów i powłok na pakowanie świeżych śliwek. Analiza z użyciem kamery termowizyjnej pozwoliła na ocenę zmian w owocach podczas przechowywania, zaś powłoka skrobiowa efektywnie opóźniała procesy degradacyjne w owocach.

Nanoparticles from biodegradable polymers are considered one of the most promising systems for biomedical application as drug delivery systems. Therefore, the synthesis and characterization of a new aliphatic biodegradable copolyester named PBS/PBDL (poly(butylene succinate-co- butylene dilinoleate)) intended to the application as drug delivery system is reported in the thesis. Surfactant-free biodegradable and narrowly distributed, nanosized spherical particles (RH < 60 nm) have been produced from the biodegradable material by applying a single-step nanoprecipitation protocol. The size of the generated polymer nanoparticles (PNPs) could be controlled by adjusting the polymer concentration, the choice of organic solvent, mixing different organic solvents or by changing temperature and ionic strength. By optimizing such parameters sub-100 nm uniform PNPs can be produced through this methodology including the advantage and ability to scale-up production. The nanoparticles structure was characterized in detail by employing a variety of scattering techniques and transmission electron microscopy (TEM). Combined static light scattering (SLS) and dynamic light scattering (DLS) measurements suggested that the nanoparticles comprise a porous core conferring them a non-compact characteristic. Their porosity...