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Thesis (Ph.D.)--Brown University, 2008. / Vita. Advisor : Edith Mathiowitz. Includes bibliographical references (leaves 70-71).

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Orientadores: Maria Helena Andrade Santana,Ricardo de Lima Zollner / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-04T03:10:16Z (GMT). No. of bitstreams: 1 Albuquerque_ElaineChristinedeMagalhaesCabral_D.pdf: 16369723 bytes, checksum: f3f48ecee87fc1981e22d876f53c0904 (MD5) Previous issue date: 2005 / Resumo: Os problemas alérgicos respiratórios afetam grande parte da população mundial e 10-40% da população brasileira. Atualmente, o tratamento dessas desordens respiratórias consiste a imunoterapia convencional e na farmacoterapia. Embora a imunoterapia convencional apresente boa eficiência no tratamento de alergias respiratórias, o longo tempo de tratamento e a presença de reações sistêmicas adversas constituem grandes desvantagens, uma vez que o alérgeno é administrado na sua forma livre. Uma alternativa para reduzir ou eliminar essas desvantagens seria a encapsulação do alérgeno em sistemas de liberação controlada. Dentre esses sistemas, lipossomas e microesferas poliméricas apresentam-se promissores, uma vez que são capazes não somente de proteger e reduzir a toxicidade do composto ativo encupsulado, mas também de aumentar seu tempo de circulação in vivo. Os lipossomas são biocompatíveis, não imunogênicos, potentes adjuvantes imunológicos e apresentam a capacidade única de interagir com as células. As microesferas, no entanto, vem sendo extensivamente usadas em sistemas de liberação devido a sua capacidade de atuar como reservatório, capaz de liberar as macromoléculas por dias, meses ou anos. O objetivo deste trabalho foi a preparação e encapsulação do extratoalérgico obtido da biomassa fúngica de Drechslera (Helminthosporium) monóceras em lipossomas e microesferas. Lipossomas convencionais e furtivos e microesferas de ácido poli-lático-co-glicólico foram usados neste trabalho... Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: Respiratory allergic disorders affect a great number of individuals throughout the world. Nowadays, conventional therapies for atopic individuals comprise specific immunotherapy and pharmacotherapy. In general, the immunotherapy using free allergens produces adverse systemic reactions of varying intensity and frequency. In order to circumvent these problems, several approaches have been explored. Among them, liposomes and microspheres have been studied as promising vehicles as carriers of allergens for desensitization immunotherapy in allergy. Liposomes are small phospholipid vesicles composed of nontoxic, biodegradable, and naturally occurring immune response and producing a pronounced depot effect after subcutaneous injection. Microspheres have also been widely investigated in drug delivery studies due to their capability of presenting antigens to the immune system over a long time. A large number of natural and synthetic polymers are potentially suitable for production of the wall-forming polymer. Synthetic biodegradable poly (lactide-co-glycolide) copolymers are among the primary candidates due to their excellent tissue biocompatibility, biodegradability and regulatory approval. The aim of this work is to prepare and characterize liposomes and micrspheres entrapping allergenic extract from Dechlera (Helminthosporium) monoceras and ovoalbumin. The in vivo effects of the sequential administration of both asjuvants containing ovoalbumin were also evaluated by analysis of immunoglobulin G (IgG) and immunoglobulin E (IgE) levels...Note: The complete abstract is available with the full electronic digital thesis or dissertations / Doutorado / Desenvolvimento de Processos Biotecnologicos / Doutor em Engenharia Química

The use of dense CO2 in polymer processing can provide a response to the need for more environmentally-friendly industrial processes. Products with high-purity, sterility, and porosity can be achieved using dense gas technology (DGT). Currently, DGT has been used in different aspects of polymer processing including polymerization, micronization, and impregnation. Due to its solubility in polymers, CO2 can penetrate and plasticize polymers, while impregnating them with low-molecular weight CO2 -soluble compounds. Biodegradable polymers and other medical-grade polymers have benefited from the application of DGT. Dense CO2 processing properties of inertness, non-toxicity, and affinity for various therapeutic compounds are specifically advantageous to the medical and biomedical industries. In this work, the different applications of DGT in polymer processing are revised, then implemented. The polymerization of polycarbonate (PC) and polycaprolactone (PCL) in dense CO2 are presented. The syntheses of both polymers were successful and were aided by the use of dense CO2 . A multi-stage approach using dense CO2 as a sweep fluid to extract the PC polymerization by-product phenol is reported. Polycaprolactone was synthesized with varying temperatures and dense CO pressures, then impregnated with a CO2 -soluble therapeutic agent. The impregnated PCL acted as a drug reservoir with a drug-loading of 27wt% and a sustained drug release profile was observed for all samples over several days. Polymer blends of PC/PCL have potential industrial and biomedical applications both in vivo and in vitro. The applicability of PCL can be extended by enhancing its mechanical properties by creating a bio-blend with a stronger polymer such as PC. In this work, PC/PCL nonporous and porous blends were produced. Three novel dense CO2 blending techniques were used. The macroporous PC/PCL blend was impregnated with a therapeutic agent using CO2 as the carrier. A drug loading of 20wt% was achieved and sustained drug release was observed over 3 days. The applicability of dense CO2 in polymer processing was further demonstrated by sterilizing macroporous PC/PCL blends and soft hydrogels with dense CO2 . The PC/PCL blends and hydrogels were inoculated with vegetative bacteria and bacterial endospores. Industrial standard sterilization levels were achieved.