Sistemas de liberação controlada vêm sendo cada vez mais utilizados em diferentes áreas tendo em vista sua aplicabilidade que os tornam uma tecnologia capaz de atender as necessidades econômicas e ambientais uma vez que permitem a utilização de princípios ativos em quantidades precisas e apenas nos locais desejados. Dentre a diversidade de opções de matrizes utilizadas nesses sistemas o poli(álcool vinílico) tem sido bastante empregado e pode ser obtido pela técnica de ciclos térmicos. Azadiractina, um princípio ativo encontrado em óleo de semente de Nim tem sido descrita como repelente de diferentes tipos de insetos e apresenta grande aplicabilidade na agricultura. Com base nas propriedades desse composto, propôs-se o desenvolvimento de um sistema de liberação controlada para combate a pulgas Ctenocephalides felis felis. No presente trabalho, foram realizadas caracterizações físico-químicas das matrizes e dispositivos através de ensaios de fração gel, intumescimento, calorimetria exploratória diferencial e microscopia eletrônica de varredura e caracterizações biológicas quanto à citotoxicidade do óleo de Nim, matrizes e dispositivos e bioensaio para análise do comportamento das pulgas na presença do óleo de Nim. As caracterizações físico-químicas permitiram a escolha da matriz mais adequada para o desenvolvimento do dispositivo. As caracterizações biológicas demonstraram ausência de citotoxicidade do óleo de Nim, das matrizes e dos dispositivos e o bioensaio resultou em 40% de mortalidade das pulgas testadas. Na cinética de liberação, verificou-se que todos os agentes encapsulantes utilizados permitiram a liberação de princípios ativos do óleo de Nim. / Controlled release systems has been increasingly used into different purposes due to its applicability that turns it onto a technology able to supply economic and environmental needs, once thats allows using precise amounts of active ingredients and only on aimed locations. Among the variety of matrix options used in this systems, poly (vinyl alcohol) has been larged employed and can be obtained by thermal cycles technics. Azadirachtin, an active ingredient found in Neem seed oil has been described as a repellent of different kinds of insects and has great agriculture\'s applicability. Based on compound properties, was proposed to develop a controlled release system to combat flea Ctenocephalides felis felis. In the present study was performed physicochemical characterizations of matrix and devices through gel fraction, swelling tests, differential scanning calorimetry, scanning electron microscopy and biological characterizations by cytotoxicity assay of Neen\'s oil, matrix and devices and analysis of flea\'s behavior at neem\'s oil presence by bioassay. The physical-chemical characterizations has enabled to choose the most suitable matrix to device\'s development. The biological characterizations has been demonstrated absence of oil\'s cytotoxicity, matrices and devices and bioassay has resulted in 40% mortality of fleas. On kinetic\'s release, was cheked that all used encapsulating agents has allowed the release neem\'s oil active principles.

Sistemas de liberação controlada vêm sendo cada vez mais utilizados em diferentes áreas tendo em vista sua aplicabilidade que os tornam uma tecnologia capaz de atender as necessidades econômicas e ambientais uma vez que permitem a utilização de princípios ativos em quantidades precisas e apenas nos locais desejados. Dentre a diversidade de opções de matrizes utilizadas nesses sistemas o poli(álcool vinílico) tem sido bastante empregado e pode ser obtido pela técnica de ciclos térmicos. Azadiractina, um princípio ativo encontrado em óleo de semente de Nim tem sido descrita como repelente de diferentes tipos de insetos e apresenta grande aplicabilidade na agricultura. Com base nas propriedades desse composto, propôs-se o desenvolvimento de um sistema de liberação controlada para combate a pulgas Ctenocephalides felis felis. No presente trabalho, foram realizadas caracterizações físico-químicas das matrizes e dispositivos através de ensaios de fração gel, intumescimento, calorimetria exploratória diferencial e microscopia eletrônica de varredura e caracterizações biológicas quanto à citotoxicidade do óleo de Nim, matrizes e dispositivos e bioensaio para análise do comportamento das pulgas na presença do óleo de Nim. As caracterizações físico-químicas permitiram a escolha da matriz mais adequada para o desenvolvimento do dispositivo. As caracterizações biológicas demonstraram ausência de citotoxicidade do óleo de Nim, das matrizes e dos dispositivos e o bioensaio resultou em 40% de mortalidade das pulgas testadas. Na cinética de liberação, verificou-se que todos os agentes encapsulantes utilizados permitiram a liberação de princípios ativos do óleo de Nim. / Controlled release systems has been increasingly used into different purposes due to its applicability that turns it onto a technology able to supply economic and environmental needs, once thats allows using precise amounts of active ingredients and only on aimed locations. Among the variety of matrix options used in this systems, poly (vinyl alcohol) has been larged employed and can be obtained by thermal cycles technics. Azadirachtin, an active ingredient found in Neem seed oil has been described as a repellent of different kinds of insects and has great agriculture\'s applicability. Based on compound properties, was proposed to develop a controlled release system to combat flea Ctenocephalides felis felis. In the present study was performed physicochemical characterizations of matrix and devices through gel fraction, swelling tests, differential scanning calorimetry, scanning electron microscopy and biological characterizations by cytotoxicity assay of Neen\'s oil, matrix and devices and analysis of flea\'s behavior at neem\'s oil presence by bioassay. The physical-chemical characterizations has enabled to choose the most suitable matrix to device\'s development. The biological characterizations has been demonstrated absence of oil\'s cytotoxicity, matrices and devices and bioassay has resulted in 40% mortality of fleas. On kinetic\'s release, was cheked that all used encapsulating agents has allowed the release neem\'s oil active principles.

Living cells accumulate compensatory solutes for protection against the harmful effects of extreme environmental conditions such as high salinity, temperature and desiccation. Even at high concentrations these solutes do not disrupt the normal cellular functions and at times counteract by stabilizing the cellular components. These properties of compensatory solutes have been exploited for stabilizing proteins and cells in vitro. Betaines are widespread natural compensatory solutes that have also been used in other applications such as therapeutic agents and polymerase chain reaction (PCR) enhancers. Some biomedical applications of novel synthetic analogues of natural betaines were investigated. Natural compensatory solutes are either dipolar zwitterionic compounds or polyhydroxyl compounds, and the physical basis of compensation may differ between these, so one focus was on synthetic betaines with hydroxyl substituents. The majority of the synthetic solutes stabilized different model proteins against stress factors such as high and low temperatures. The presence of hydroxyl groups improved protection against desiccation. The observed stabilization effect is not just on the catalytic activity of the enzyme, but also on its structural conformation. Synthetic compensatory solutes have a potential application as protein stabilizers. Dimethylthetin was evaluated as a therapeutic agent and found to be harmful in a sheep model. However, from the study we were able to generate a large-animal continuous ambulatory peritoneal dialysis (CAPD) model and showed that glycine betaine could be added to the dialysis fluid in chronic renal failure. Some synthetic compensatory solutes reduce the melting temperatures of DNA better than most natural solutes. Synthetic solutes were identified that have potential to enhance PCR and could replace some reagents marketed by commercial suppliers. Density, viscosity and molecular model data on the solutes showed correlations with the biochemical effects of the solutes, but no physical measurements were found that reliably predicted their potential for biotechnological applications.