Interações de terpenos com membranas de eritrócito, fibroblasto, estrato córneo e membrana modelo e interações de uma nanopartícula de ouro com membranas modelo

• Autor(a) principal: Mendanha Neto, Sebastião Antônio
• Data de Publicação: 2014
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• dARK ID: ark:/38995/001300000bx2m
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/3993
• topic: Membranas biológicas; Ressonância paramagnética eletrônica; Espectroscopia de ressonância magnética; Nano partículas magnéticas - ouro; Electron paramagnetic resonance; Confocal microscopy; Atomic force microscopy; Biological membranes; AURORA-DSG; CIENCIAS EXATAS E DA TERRA::FISICA

The interactions of terpenes with membranes of erythrocyte, fibroblasts, stratum corneum and the model membranes of 1,2-dipalmitoylsn -glycero-3-phosphocholine were investigated by using the the electron paramagnetic resonance and fluorescence spectroscopic of lipophilic probes. It has been shown that when added at high concentrations to systems having a high lipid/solvent ratio, terpenes such as 1,8-cineol, α-terpineol, (+)-limonene and nerolidol are able to self-stabilize in molecular aggregates which can extract the bilayers lipids. Studies on the hemolytic and cytotoxic potential of various terpenes showed that cell damage caused by these molecules are concentration dependent and that among the studied terpenes, nerolidol and α-terpineol are the most hemolytic and cytotoxic, while (+)-limonene and 1,8-cineole are the least hemolytic and cytotoxic. However, the low correlation between these two tests indicates that the processes involved in each case are not completely dependent. It was also shown that once embedded in the membrane, terpenes increase the fluidity of lipid bilayers and decrease the temperature of the main phase transition. Differences between increased fluidity promoted by sesquiterpene nerolidol and all monoterpenes studied were observed. Meanwhile, in a comparison of the effect of the monoterpenes studied, no significant differences in their ability to increase membrane fluidity were detected. Furthermore, it was demonstrated by using confocal and atomic force microscopy and fluorescence spectroscopy that the 1,2-distearoylsn -glycero-3-(Aurora nanoparticles) is better incorporated in lipid membranes under fluid phase and that the addition of 0.1% of these conjugated nanoparticles do not produces large variations in membrane fluidity and no causes substantial morphological changes of lipid bilayers.