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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

Arrabidaea chica Verlot : formulações de liberação sustentada para aplicação em úlceras de mucosa e pele / Arrabidaea chica Verlot : controled release formulations with aplications for ulcer lesions

Servat-Medina, Leila, 1982- 24 August 2018 (has links)
Orientadores: Mary Ann Foglio, João Ernesto de Carvalho, Rodney Alexandre Ferreira Rodrigues / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-24T17:52:12Z (GMT). No. of bitstreams: 1 Servat-Medina_Leila_D.pdf: 4805835 bytes, checksum: b2b1fd8454db3c90fb0128ee69d626bf (MD5) Previous issue date: 2014 / Resumo: A espécie Arrabidaea chica, conhecida como crajiru, faz parte da relação nacional de plantas medicinais de interesse ao SUS. Estudos desenvolvidos no CPQBA-UNICAMP comprovaram que o extrato bruto de A. chica possui ação cicatrizante, antiulcerogênica e antioxidante. Este trabalho teve como objetivo delinear e avaliar sistemas farmacêuticos contendo o extrato padronizado de A. chica, para o tratamento de lesões de pele e mucosa. Foram obtidas nanopartículas de quitosana pelo método de reticulação. Dentre os parâmetros avaliados estipulou-se como melhores condições para produção de nanopartículas o emprego do tripolifosfato como reticulante nas proporções de 1:5 (massa) e 1:10 (volume) em relação a quitosana. Para as aplicações tópicas, as nanopartículas de A. chica foram veiculadas em esponjas, filmes absorvíveis de álcool polivinílico ou hidrogéis de ácido hialurônico. Estudos in vitro utilizando fibroblastos humanos demonstraram a atividade das nanopartículas de A. chica na proliferação e migração celular. Estudos in vivo empregando ratos e hamsters forneceram parâmetros para padronização de modelos de mucosite gastrointestinal e oral, respectivamente. A atividade das nanopartículas em úlceras de mucosa foi evidenciada nos modelos de úlcera gástrica induzidas por etanol ou indometacina, com redução das lesões ulcerativas de 76% e 58%, respectivamente, quando comparadas ao grupo controle negativo. O efeito cicatrizante de filmes absorvíveis ou hidrogéis incorporados com as nanopartículas de A. chica foram avaliados em modelo de úlcera dérmica em ratos. A contração da área da ferida chegou a 79% nos animais tratados com os filmes carregados com 0,5 mg de nanopartículas e 85% de contração nos animais que receberam hidrogéis contendo 1,5 mg de nanopartículas. Os resultados demonstraram que a produção de nanopartículas de A. chica e dos sistemas de transporte foi viável, caracterizando-se como uma alternativa válida para a veiculação do extrato de A. chica, além de propiciar a redução da dose necessária para a atividade / Abstract: Arrabidaea chica, known as crajiru, is part of the national Unified Health System from Brazil (SUS) list of medicinal plants of interest. Studies conducted at CPQBA- UNICAMP showed that the species demonstrated wound healing, antiulcerogenic and antioxidant properties. This study aimed the evaluation of pharmaceutical systems employing standardized extract for treatment of skin and mucosal wounds. Chitosan nanoparticles were obtained using the crosslink method. The protocol that showed best conditions to produce nanoparticles, among those tested, used tripolyphosphate as a cross-linker, in 1:5 (mass) and 1:10 (volume) proportions compared to chitosan. For topical applications, A. chica nanoparticles were incorporated into sponges, polyvinyl alcohol absorbable films or hyaluronic acid hydrogels. In vitro studies with human fibroblasts showed the activity of A. chica nanoparticles in cell proliferation and migration. In vivo studies with rats and hamsters provided the standardization parameters for gastrointestinal and mucositis models respectively. A chica nanoparticles demonstrated inhibition of mucosal ulcerations of gastric ulcer induced by ethanol or indomethacin models, improving ulcerative wound healing by 76% and by 58% respectively, in comparison to negative control groups. Those same samples incorporated into absorbable films or hydrogels were evaluated on wound healing activity using a rat dermal ulcer model. Animals treated with loaded films with 0.5 mg of nanoparticles achieved 79% in wound area contraction, whereas animals receiving hydrogels containing 1.5 mg of nanoparticles achieved 85%. These results showed that the production of A. chica nanoparticles and transport systems were practicable, demonstrating to be a valid alternative for incorporation of A. chica extracts, allowing decrease of the required dose to achieve the desired effect / Doutorado / Farmacologia, Anestesiologia e Terapeutica / Doutora em Odontologia
2

Investigation On Ag And ZnO Based Nanohybrids As Bactericides For The Purification Of Water And Elucidation Of Possible Mechanisms For Their Bio-activity

Ghosh, Somnath 08 1900 (has links) (PDF)
Chapter I: This chapter briefly gives an introduction about microorganisms, their varieties, growth, reproduction etc. In particular, about bacterial function. A sincere attempt is made to review this briefly, including an account of the studies already reported in the literature. Chapter II deals with the antimicrobial activity of Ag/agar film on Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Candida albicans (C. albicans). In particular, films were repeatedly cycled for its antimicrobial activity. The antimicrobial activity of Ag/agar film was found to be in the order, C. albicans > E. coli > S. aureus. Chapter III describes the synthesis of Ag@AgI NPs in agarose matrix. A detailed antibacterial studies including repetitive cycles are carried out on E. coli and S. aureus bacteria. EPR and TEM studies are carried out on the Ag@AgI/Agarose and the bacteria, respectively, to elucidate a possible mechanism for killing of the bacteria. The hybrid could be recycled for the antibacterial activity many times and is found to be non toxic towards human cervical cancer cell (HeLa cells). Chapter IV reports the antibacterial efficacy of silver nanoparticles (Ag NPs) deposited alternatively layer by layer (LBL) on chitosan polymer in the form of a thin film over a quartz plate and stainless steel strip against E. coli. AFM studies are carried out on the microbe to know the morphological changes affected by the hybrid film. The hybrid films on aging (3 months) are found to be as bioactive as before. Cytotoxicity experiments indicated good biocompatibility. Chapter V describes the fabrication of carbon foam porous electrode modified with reduced graphene oxide-Ag nanocomposites. The device can perform sterilization by killing pathogenic microbes with the aid of just one 1.5V battery with very little power consumption. Chapter VI Here we have studied in particular a property say the influence of surface defect in the production of ROS by ZnO NPs and in turn the bactericide activity. Secondly, a homogeneous ZnO and ZnO/Ag nanohybrid has been synthesized by employing chitosan as mediator. The synergistic antibacterial effect of ZnO/Ag nanohybrid on bacteria is found to be more effective, compared to the individual components (ZnO and Ag). A possible mechanism has been proposed for the death of bacteria by ZnO/Ag nanohybrid, based on EPR studies and TEM studies.

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