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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Desenvolvimento tecnológico de nanoemulsão contendo ácido azelaico e avaliação da inibição da tirosinase, permeação cutânea e perfil sensorial

Berlitz, Simone Jacobus January 2017 (has links)
O ácido azelaico é um fármaco amplamente utilizado como tratamento em diversas doenças de pele, como acne, rosácea e melasma. A utilização de sistemas nanoestruturados para aplicação tópica se mostra interessante visto que o menor tamanho de partícula proporciona uma melhor entrega de fármacos até o seu sítio de ação. É promissor o desenvolvimento de formulações capazes de diminuir os efeitos adversos do ácido azelaico e intensificar sua eficácia no tratamento de desordens pigmentárias da pele, aliado ao desenvolvimento de uma formulação com controle de permeação e perfil sensorial que facilite a adesão ao tratamento. O objetivo do presente trabalho é desenvolver uma nanoemulsão contendo ácido azelaico e realizar ensaios da tirosinase, permeação cutânea e análise sensorial da formulação desenvolvida. A nanoemulsão foi preparada através da técnica de homogeneização a alta velocidade. A caracterização físico-química avaliou os parâmetros de diâmetro médio de partícula e distribuição do tamanho de partícula pela técnica de difração de laser, o potencial zeta foi medido por mobilidade eletroforética, o pH por potenciometria e teor e eficiência de encapsulação por CLAE. A morfologia foi observada por microscopia eletrônica de transmissão. A nanoemulsão foi estável por 30 dias a 30°C/ 65% UR. A formulação apresentou teor de 10 mg/mL, tamanho de partícula de 419 ± 23 nm, distribuição monomodal, eficiência de encapsulação de 84,65%, potencial zeta de -10,9 ± 0,44 mV e pH de 5,01 ± 0,01. Para verificar a eficácia despigmentante da formulação foi realizado o ensaio in vitro de inibição de tirosinase, onde a nanoemulsão se mostrou mais eficaz que o controle com o fármaco na sua forma livre. O ensaio de permeação cutânea in vitro em células de difusão de Franz foi realizado com pele de orelha de porcos durante 24 horas e ele demonstrou que a formulação nanotecnológica conseguiu atingir as camadas mais profundas da pele (epiderme viável e derme), permitindo que o fármaco alcance o seu sítio de ação, facilitando a inibição da síntese de melanina. Foi realizada análise sensorial descritiva, com 16 voluntários demonstrando que a formulação apresentou maior espalhabilidade e menor brilho que um produto já disponível no mercado. Portanto, a nanoemulsão desenvolvida se mostra promissora para utilização no tratamento de melasma, inclusive o dérmico. / Azelaic acid is a drug commonly used in the treatment of several skin diseases such as acne, rosacea and melasma. Nanostructured systems for topical application are interesting because its smaller particle size lead to a better drug delivery to its action site. Therefore, it is promising to develop formulations able to lower azelaic acid’s side effects and increase its efficacy as a skin whitening agent as well as control its permeation and shows a sensory profile that helps with patient adherence. The aim of the present work is to develop an azelaic-acid loaded nanoemulsion, evaluating its tyrosinase inhibition, skin permeation and sensory profile. The nanoemulsion was prepared using high shear homogenization. Its characterization was conducted evaluating the average particle diameter through laser diffraction, the zeta potential by eletrophoretic mobility, pH by potentiometry and drug content and encapsulation efficiency by HPLC. The morphology of the nanoemulsion was observed by transmission electron microscopy. The product was stable for 30 days at 30°C/ 65 % RH. The theoretical drug content was 10 mg/mL and the particle size 419 ± 23 nm with a monomodal distribution profile, encapsulation efficiency of 84,65% and the zeta potencial was -10,9 ± 0,44 mV while the pH was 5,01 ± 0,01. To evaluate the formulation’s whitening efficacy, tyrosinase inhibition was calculated and the azelaicacid loaded nanoemulsion was more effective than the control with the drug in its free form. The in vitro permeation study using Franz diffusion cells was conducted for 24 hours, using pig ear skin and showed that the formulation was able to permeate through the skin and reach the deeper layers (viable epidermis and dermis), allowing the drug to reach its action site, improving the melanin synthesis inhibition. To help understand the sensory profile of the nanoemulsion, a descriptive sensory evaluation was conducted with 16 volunteers. The nanoemulsion’s sensory profile showed a better spreadability and lower shine comparing with a product already available in pharmacies. Hence, the azelaic acid-loaded nanoemulsion developed in this word seems to be promising as a treatment for pigmentary skin disorders as dermal melasma.
2

Desenvolvimento tecnológico de nanoemulsão contendo ácido azelaico e avaliação da inibição da tirosinase, permeação cutânea e perfil sensorial

Berlitz, Simone Jacobus January 2017 (has links)
O ácido azelaico é um fármaco amplamente utilizado como tratamento em diversas doenças de pele, como acne, rosácea e melasma. A utilização de sistemas nanoestruturados para aplicação tópica se mostra interessante visto que o menor tamanho de partícula proporciona uma melhor entrega de fármacos até o seu sítio de ação. É promissor o desenvolvimento de formulações capazes de diminuir os efeitos adversos do ácido azelaico e intensificar sua eficácia no tratamento de desordens pigmentárias da pele, aliado ao desenvolvimento de uma formulação com controle de permeação e perfil sensorial que facilite a adesão ao tratamento. O objetivo do presente trabalho é desenvolver uma nanoemulsão contendo ácido azelaico e realizar ensaios da tirosinase, permeação cutânea e análise sensorial da formulação desenvolvida. A nanoemulsão foi preparada através da técnica de homogeneização a alta velocidade. A caracterização físico-química avaliou os parâmetros de diâmetro médio de partícula e distribuição do tamanho de partícula pela técnica de difração de laser, o potencial zeta foi medido por mobilidade eletroforética, o pH por potenciometria e teor e eficiência de encapsulação por CLAE. A morfologia foi observada por microscopia eletrônica de transmissão. A nanoemulsão foi estável por 30 dias a 30°C/ 65% UR. A formulação apresentou teor de 10 mg/mL, tamanho de partícula de 419 ± 23 nm, distribuição monomodal, eficiência de encapsulação de 84,65%, potencial zeta de -10,9 ± 0,44 mV e pH de 5,01 ± 0,01. Para verificar a eficácia despigmentante da formulação foi realizado o ensaio in vitro de inibição de tirosinase, onde a nanoemulsão se mostrou mais eficaz que o controle com o fármaco na sua forma livre. O ensaio de permeação cutânea in vitro em células de difusão de Franz foi realizado com pele de orelha de porcos durante 24 horas e ele demonstrou que a formulação nanotecnológica conseguiu atingir as camadas mais profundas da pele (epiderme viável e derme), permitindo que o fármaco alcance o seu sítio de ação, facilitando a inibição da síntese de melanina. Foi realizada análise sensorial descritiva, com 16 voluntários demonstrando que a formulação apresentou maior espalhabilidade e menor brilho que um produto já disponível no mercado. Portanto, a nanoemulsão desenvolvida se mostra promissora para utilização no tratamento de melasma, inclusive o dérmico. / Azelaic acid is a drug commonly used in the treatment of several skin diseases such as acne, rosacea and melasma. Nanostructured systems for topical application are interesting because its smaller particle size lead to a better drug delivery to its action site. Therefore, it is promising to develop formulations able to lower azelaic acid’s side effects and increase its efficacy as a skin whitening agent as well as control its permeation and shows a sensory profile that helps with patient adherence. The aim of the present work is to develop an azelaic-acid loaded nanoemulsion, evaluating its tyrosinase inhibition, skin permeation and sensory profile. The nanoemulsion was prepared using high shear homogenization. Its characterization was conducted evaluating the average particle diameter through laser diffraction, the zeta potential by eletrophoretic mobility, pH by potentiometry and drug content and encapsulation efficiency by HPLC. The morphology of the nanoemulsion was observed by transmission electron microscopy. The product was stable for 30 days at 30°C/ 65 % RH. The theoretical drug content was 10 mg/mL and the particle size 419 ± 23 nm with a monomodal distribution profile, encapsulation efficiency of 84,65% and the zeta potencial was -10,9 ± 0,44 mV while the pH was 5,01 ± 0,01. To evaluate the formulation’s whitening efficacy, tyrosinase inhibition was calculated and the azelaicacid loaded nanoemulsion was more effective than the control with the drug in its free form. The in vitro permeation study using Franz diffusion cells was conducted for 24 hours, using pig ear skin and showed that the formulation was able to permeate through the skin and reach the deeper layers (viable epidermis and dermis), allowing the drug to reach its action site, improving the melanin synthesis inhibition. To help understand the sensory profile of the nanoemulsion, a descriptive sensory evaluation was conducted with 16 volunteers. The nanoemulsion’s sensory profile showed a better spreadability and lower shine comparing with a product already available in pharmacies. Hence, the azelaic acid-loaded nanoemulsion developed in this word seems to be promising as a treatment for pigmentary skin disorders as dermal melasma.
3

Desenvolvimento tecnológico de nanoemulsão contendo ácido azelaico e avaliação da inibição da tirosinase, permeação cutânea e perfil sensorial

Berlitz, Simone Jacobus January 2017 (has links)
O ácido azelaico é um fármaco amplamente utilizado como tratamento em diversas doenças de pele, como acne, rosácea e melasma. A utilização de sistemas nanoestruturados para aplicação tópica se mostra interessante visto que o menor tamanho de partícula proporciona uma melhor entrega de fármacos até o seu sítio de ação. É promissor o desenvolvimento de formulações capazes de diminuir os efeitos adversos do ácido azelaico e intensificar sua eficácia no tratamento de desordens pigmentárias da pele, aliado ao desenvolvimento de uma formulação com controle de permeação e perfil sensorial que facilite a adesão ao tratamento. O objetivo do presente trabalho é desenvolver uma nanoemulsão contendo ácido azelaico e realizar ensaios da tirosinase, permeação cutânea e análise sensorial da formulação desenvolvida. A nanoemulsão foi preparada através da técnica de homogeneização a alta velocidade. A caracterização físico-química avaliou os parâmetros de diâmetro médio de partícula e distribuição do tamanho de partícula pela técnica de difração de laser, o potencial zeta foi medido por mobilidade eletroforética, o pH por potenciometria e teor e eficiência de encapsulação por CLAE. A morfologia foi observada por microscopia eletrônica de transmissão. A nanoemulsão foi estável por 30 dias a 30°C/ 65% UR. A formulação apresentou teor de 10 mg/mL, tamanho de partícula de 419 ± 23 nm, distribuição monomodal, eficiência de encapsulação de 84,65%, potencial zeta de -10,9 ± 0,44 mV e pH de 5,01 ± 0,01. Para verificar a eficácia despigmentante da formulação foi realizado o ensaio in vitro de inibição de tirosinase, onde a nanoemulsão se mostrou mais eficaz que o controle com o fármaco na sua forma livre. O ensaio de permeação cutânea in vitro em células de difusão de Franz foi realizado com pele de orelha de porcos durante 24 horas e ele demonstrou que a formulação nanotecnológica conseguiu atingir as camadas mais profundas da pele (epiderme viável e derme), permitindo que o fármaco alcance o seu sítio de ação, facilitando a inibição da síntese de melanina. Foi realizada análise sensorial descritiva, com 16 voluntários demonstrando que a formulação apresentou maior espalhabilidade e menor brilho que um produto já disponível no mercado. Portanto, a nanoemulsão desenvolvida se mostra promissora para utilização no tratamento de melasma, inclusive o dérmico. / Azelaic acid is a drug commonly used in the treatment of several skin diseases such as acne, rosacea and melasma. Nanostructured systems for topical application are interesting because its smaller particle size lead to a better drug delivery to its action site. Therefore, it is promising to develop formulations able to lower azelaic acid’s side effects and increase its efficacy as a skin whitening agent as well as control its permeation and shows a sensory profile that helps with patient adherence. The aim of the present work is to develop an azelaic-acid loaded nanoemulsion, evaluating its tyrosinase inhibition, skin permeation and sensory profile. The nanoemulsion was prepared using high shear homogenization. Its characterization was conducted evaluating the average particle diameter through laser diffraction, the zeta potential by eletrophoretic mobility, pH by potentiometry and drug content and encapsulation efficiency by HPLC. The morphology of the nanoemulsion was observed by transmission electron microscopy. The product was stable for 30 days at 30°C/ 65 % RH. The theoretical drug content was 10 mg/mL and the particle size 419 ± 23 nm with a monomodal distribution profile, encapsulation efficiency of 84,65% and the zeta potencial was -10,9 ± 0,44 mV while the pH was 5,01 ± 0,01. To evaluate the formulation’s whitening efficacy, tyrosinase inhibition was calculated and the azelaicacid loaded nanoemulsion was more effective than the control with the drug in its free form. The in vitro permeation study using Franz diffusion cells was conducted for 24 hours, using pig ear skin and showed that the formulation was able to permeate through the skin and reach the deeper layers (viable epidermis and dermis), allowing the drug to reach its action site, improving the melanin synthesis inhibition. To help understand the sensory profile of the nanoemulsion, a descriptive sensory evaluation was conducted with 16 volunteers. The nanoemulsion’s sensory profile showed a better spreadability and lower shine comparing with a product already available in pharmacies. Hence, the azelaic acid-loaded nanoemulsion developed in this word seems to be promising as a treatment for pigmentary skin disorders as dermal melasma.
4

Formulation, in vitro release and transdermal diffusion of azelaic acid with topical niacinamide / J.M. Moolman

Moolman, Judith Margaretha January 2010 (has links)
Acne is a common skin disease that affects the follicular unit of the skin. Inflammatory- and noninflammatory forms of acne exist. The most affected areas on the body include the face, upper part of the chest and the back. These are the areas with the most sebaceous follicles. Acne occurs when hyperkeratinisation causes the cells of the hair follicle to shed too fast. These cells then block the follicle opening. Thus, sebum cannot pass through the hair follicle onto the skin. The human skin is composed of three layers, namely the epidermis, which acts as a waterproof layer and a barrier to infections; the dermis, which contains the skin appendages; and the subcutaneous fat layer. Skin acts as a protective layer against pathogens and damage to the body. It also provides a semi-impermeable barrier to prevent water loss. Azelaic acid and niacinamide are both currently used in the treatment of acne. Azelaic acid is a saturated dicarboxylic acid which is used to treat mild to moderate acne. It has antibacterial, keratolytic and comedolytic properties. Niacinamide, on the other hand, is the amide of nicotinic acid and is beneficial in the treatment of both papular and pustular acne. It has a demonstrated anti-inflammatory action and causes dose-dependent inhibition of sebocyte secretions. The Pheroid™ delivery system is a colloidal system that consists of even lipid-based submicron-and micron-sized structures that are very unique in nature. This technology is able to improve the absorption and/or efficacy of various active ingredients, as well as other compounds. In this study, a cream, Pheroid™ cream, a gel and a Pheroid™ gel were formulated, containing both azelaic acid and niacinamide. Stability tests were conducted on these formulations for six months, and it was established that none of the formulations were stable under the different storage conditions. Tests that were conducted during stability testing, as determined by the Medicines Control Council, included: assay, mass variation, appearance, viscosity, pH determination and confocal laser scanning microscopy (CLSM). Diffusion studies (12 hours long in total) with vertical Franz cells were conducted with Caucasian female skin obtained after abdominoplastic surgery. Tape-stripping followed in order to establish the epidermis and dermis concentrations of azelaic acid and niacinamide. Significant concentrations of both active ingredients were found in the epidermis and the dermis after 12 hours. / Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2010.
5

Formulation, in vitro release and transdermal diffusion of azelaic acid with topical niacinamide / J.M. Moolman

Moolman, Judith Margaretha January 2010 (has links)
Acne is a common skin disease that affects the follicular unit of the skin. Inflammatory- and noninflammatory forms of acne exist. The most affected areas on the body include the face, upper part of the chest and the back. These are the areas with the most sebaceous follicles. Acne occurs when hyperkeratinisation causes the cells of the hair follicle to shed too fast. These cells then block the follicle opening. Thus, sebum cannot pass through the hair follicle onto the skin. The human skin is composed of three layers, namely the epidermis, which acts as a waterproof layer and a barrier to infections; the dermis, which contains the skin appendages; and the subcutaneous fat layer. Skin acts as a protective layer against pathogens and damage to the body. It also provides a semi-impermeable barrier to prevent water loss. Azelaic acid and niacinamide are both currently used in the treatment of acne. Azelaic acid is a saturated dicarboxylic acid which is used to treat mild to moderate acne. It has antibacterial, keratolytic and comedolytic properties. Niacinamide, on the other hand, is the amide of nicotinic acid and is beneficial in the treatment of both papular and pustular acne. It has a demonstrated anti-inflammatory action and causes dose-dependent inhibition of sebocyte secretions. The Pheroid™ delivery system is a colloidal system that consists of even lipid-based submicron-and micron-sized structures that are very unique in nature. This technology is able to improve the absorption and/or efficacy of various active ingredients, as well as other compounds. In this study, a cream, Pheroid™ cream, a gel and a Pheroid™ gel were formulated, containing both azelaic acid and niacinamide. Stability tests were conducted on these formulations for six months, and it was established that none of the formulations were stable under the different storage conditions. Tests that were conducted during stability testing, as determined by the Medicines Control Council, included: assay, mass variation, appearance, viscosity, pH determination and confocal laser scanning microscopy (CLSM). Diffusion studies (12 hours long in total) with vertical Franz cells were conducted with Caucasian female skin obtained after abdominoplastic surgery. Tape-stripping followed in order to establish the epidermis and dermis concentrations of azelaic acid and niacinamide. Significant concentrations of both active ingredients were found in the epidermis and the dermis after 12 hours. / Thesis (M.Sc. (Pharmaceutics))--North-West University, Potchefstroom Campus, 2010.
6

Dietary Peroxidized Lipids and Intestinal Apolipoprotein Synthesis

Jiang, Xueting 09 July 2014 (has links)
No description available.
7

Molecular and Biochemical Signaling Underlying Arabidopsis-Bacterial/Virus/Fungal Interactions

El-Shetehy, Mohamed H. 01 January 2016 (has links)
Systemic acquired resistance (SAR) is a form of inducible defense response triggered upon localized infection that confers broad-spectrum disease resistance against secondary infections. Several factors are known to regulate SAR and these include phenolic phytohormone salicylic acid (SA), phosphorylated sugar glycerol-3-phosphate (G3P), and dicarboxylic acid azelaic acid (AzA). This study evaluated a role for free radicals nitric oxide (NO) and reactive oxygen species (ROS) in SAR. Normal accumulation of both NO and ROS was required for normal SAR and mutations preventing NO/ROS accumulation and/or biosynthesis compromised SAR. A role for NO and ROS was further established using pharmacological approaches. Notably, both NO and ROS conferred SAR in a concentration dependent manner. This was further established using genetic mutants that accumulated high levels of NO. NO/ROS acted upstream of G3P and in parallel to SA. Collectively, these results suggest that NO and ROS are essential components of the SAR pathway.
8

Développement de voies alternatives de coupure oxydante d’alcools vicinaux biosourcés / Development of alternatives oxidative cleavage of biosourced vicinal alcohols

Guicheret, Boris 10 February 2017 (has links)
La transformation d'alcènes par oxydation peut conduire à des familles de composés à plus haute valeur ajoutée utilisés comme intermédiaires de synthèse dans les domaines de l'industrie chimique, pharmaceutique, cosmétique et de la parfumerie. L'objectif de ce projet est de développer un procédé intégré économiquement et écologiquement viable pour la production industrielle d'acides mono et di-carboxyliques via l'oxydation de dérivés d'huiles végétales. La méthode de synthèse proposée repose sur deux étapes consécutives mettant en œuvre la formation de diols correspondants, aujourd'hui bien maîtrisée par OLEON à l'échelle pilote, suivit de La préparation d'acides carboxyliques en milieu oxydant et en présence d'un catalyseur supporté. L'originalité et la force du procédé proposé résident dans la réalisation de cette transformation faite en présence d'oxygène et d'un catalyseur supporté. Une compréhension fine du mécanisme a été nécessaire pour nous permettre d'une part d'atteindre des rendements élevés en produits désirés et d'autre part de lever les difficultés inhérentes à la montée en échelle. L'analyse des intermédiaires réactionnels ainsi que l'élaboration de méthodologies innovantes d'accès à ces intermédiaires ont été considérées. L'objectif final de ce projet est la mise en place d'un procédé intégré dédié à la transformation de dérivés d'huile végétale en produits chimiques valorisables / Oxidation reactions are widely practiced in the Chemical Industry and products obtained through this method represent a huge market. The transformation of alkenes through oxidation processes leads to the production of a large panel of compounds that are used as such or as intermediates in the preparation of organic chemicals, perfumes, cosmetics or pharmaceutical products. The aim of this project is to develop an economically and environmentally viable integrated process for the industrial production of mono and di-carboxylic acids of high purity from the oxidative cleavage of vegetable oils. The synthetic process, dealing with the cleavage of unsaturated fatty acids, involves two distinct successive steps. The formation of the corresponding diols, a well mastered transformation at pilot scale recently patented by OLEON, then the production of mono and dicarboxylic acids in oxidative conditions, which is the key challenging step The originality and the strength of the proposed process are to perform this second transformation with oxygen as oxidant and in the presence of a supported catalyst. Nevertheless, a full understanding of the mechanism is required in order to reach high yields and selectivity in one hand and to facilitate the scale-up stage in an other hand. The analysis and new synthesis methodology of this intermediates was considered. The final objective of this project is to set up an integrated process from the initial chosen feedstock down to the valuable chemicals
9

Sìntese de materiais poliméricos contendo moléculas bioativas e materiais de fontes renováveis via catálise enzimática / Synthesis of polymeric materials containing bioactive molecules using renewable raw material via enzymatic catalysis

Barizon, Leonardo Almeida 14 May 2013 (has links)
Desde a invenção do primeiro polímero sintético por John Wesley em 1868, vem crescendo continuamente a utilização desta classe de materiais. Atualmente, é grande o interesse em agregar aos mesmos atributos mais nobres, tais como sua utilização em dispositivos biológicos, qualidade de rápida degradação e, mais recentemente, a preferência por aqueles provenientes de matéria prima renovável, que possam diminuir o impacto ambiental gerado pelo uso de petróleo e derivados. O objetivo deste trabalho é sintetizar materiais provenientes de fonte de matéria prima renovável e de fácil degradação, através de sínteses enzimáticas, evitando assim o uso de catalisadores metálicos tóxicos. Além disso, pretendeu-se agregar moléculas biologicamente ativas, de forma que os produtos finais possam exibir propriedades farmacológicas. As substâncias bioativas selecionadas para este trabalho foram: pantenol, ácido azeláico, ácido cítrico, e pantolactona. Destas moléculas, foram sintetizados 8 materiais poliméricos: poli(azelato de pantenila), poli(adipato de pantenila), poli(adipato de isosorbila-co-pantenila), poli(azelato de isosorbila), poli(adipato-co-azelato de isosorbila), poli(citrato de isosorbila), poli(adipato de isosorbila-co-citrato) e oligômero de polipantolactona. Todos os materiais foram sintetizados utilizando a enzima Candida antarctica fração B (CAL-B) como catalisador, em solvente orgânico, utilizando peneira molecular para remoção do subproduto da reação. As caracterizações foram feitas através de RMN-1H, MALDI-ToF e GPC. / Since the invention of the first synthetic polymer by John Wesley in 1868, the use of this class of materials has continuously grown. Currently, there is a great interest in adding nobler attributes to these materials, such as their use in biological devices, quality of rapid degradation and, more recently, the preference for those made from renewable feedstock, reducing the environmental impact generated by the use oil and derivatives. The objective of this work is to create materials of renewable material origin and easy degradation, using enzymatic catalysis thus avoiding the use of toxic metal catalysts. Furthermore, we intended to add biologically active molecules, so that the final products may exhibit pharmacological properties. The bioactive substances selected for this study were: panthenol, azelaic acid, citric acid, and pantolactone. From these molecules eight different polymeric materials were synthesized: poly(pantenyl azelate), poly(pantenyl adipate), poly(isosorbyl-co-pantenyl adipate), poly(isosorbyl azelate), poly(isosorbyl adipate-co-azelate) poly(isosorbyl citrate), poly(isosorbyl adipate-co-citrate) and oligomer of polypantolactone. All materials were synthesized using the enzyme Candida antarctica fraction B (CAL-B) as catalyst in organic solvent using molecular sieves to remove the byproduct of the reaction. The characterizations were made by 1H NMR, MALDI-ToF and SEC.
10

Sìntese de materiais poliméricos contendo moléculas bioativas e materiais de fontes renováveis via catálise enzimática / Synthesis of polymeric materials containing bioactive molecules using renewable raw material via enzymatic catalysis

Leonardo Almeida Barizon 14 May 2013 (has links)
Desde a invenção do primeiro polímero sintético por John Wesley em 1868, vem crescendo continuamente a utilização desta classe de materiais. Atualmente, é grande o interesse em agregar aos mesmos atributos mais nobres, tais como sua utilização em dispositivos biológicos, qualidade de rápida degradação e, mais recentemente, a preferência por aqueles provenientes de matéria prima renovável, que possam diminuir o impacto ambiental gerado pelo uso de petróleo e derivados. O objetivo deste trabalho é sintetizar materiais provenientes de fonte de matéria prima renovável e de fácil degradação, através de sínteses enzimáticas, evitando assim o uso de catalisadores metálicos tóxicos. Além disso, pretendeu-se agregar moléculas biologicamente ativas, de forma que os produtos finais possam exibir propriedades farmacológicas. As substâncias bioativas selecionadas para este trabalho foram: pantenol, ácido azeláico, ácido cítrico, e pantolactona. Destas moléculas, foram sintetizados 8 materiais poliméricos: poli(azelato de pantenila), poli(adipato de pantenila), poli(adipato de isosorbila-co-pantenila), poli(azelato de isosorbila), poli(adipato-co-azelato de isosorbila), poli(citrato de isosorbila), poli(adipato de isosorbila-co-citrato) e oligômero de polipantolactona. Todos os materiais foram sintetizados utilizando a enzima Candida antarctica fração B (CAL-B) como catalisador, em solvente orgânico, utilizando peneira molecular para remoção do subproduto da reação. As caracterizações foram feitas através de RMN-1H, MALDI-ToF e GPC. / Since the invention of the first synthetic polymer by John Wesley in 1868, the use of this class of materials has continuously grown. Currently, there is a great interest in adding nobler attributes to these materials, such as their use in biological devices, quality of rapid degradation and, more recently, the preference for those made from renewable feedstock, reducing the environmental impact generated by the use oil and derivatives. The objective of this work is to create materials of renewable material origin and easy degradation, using enzymatic catalysis thus avoiding the use of toxic metal catalysts. Furthermore, we intended to add biologically active molecules, so that the final products may exhibit pharmacological properties. The bioactive substances selected for this study were: panthenol, azelaic acid, citric acid, and pantolactone. From these molecules eight different polymeric materials were synthesized: poly(pantenyl azelate), poly(pantenyl adipate), poly(isosorbyl-co-pantenyl adipate), poly(isosorbyl azelate), poly(isosorbyl adipate-co-azelate) poly(isosorbyl citrate), poly(isosorbyl adipate-co-citrate) and oligomer of polypantolactone. All materials were synthesized using the enzyme Candida antarctica fraction B (CAL-B) as catalyst in organic solvent using molecular sieves to remove the byproduct of the reaction. The characterizations were made by 1H NMR, MALDI-ToF and SEC.

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