Propriedades de vesículas unilamelares gigantes / Properties of Giant Unillamelar Vesicles

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

The stability of giant unilamellar vesicles (GUVs) has been monitored by phase contrast and fluorescence microscopy, using sugar gradients, sodium 1,3,6,8 pirene tetrasulfonate (PTS) as fluorescent probe, 1,1-dimethyl-4,4-bipiridinium chloride (MV) as fluorescence quencher and 2-(12-(7-nitrobenz-2-oxa-1,3-diazol-4-il) amino) dodecanoyl-1-hexadecanoyl-sn-glicero-3-phosphocholine (NBD-PC) as fluorescent lipid analog. An accentuated variability in the individual behaviour of GUVs was observed as far as (i) stability of encapsulation; (ii) lipid bilayer-surface interactions and; (iii) lipid structures connected to GUVs are concerned. Experimental results can be explained by transient pores formation due to an increase in lipid bilayer tension. After processes of bilayer tension generation, pores are opened, while effluxes of GUVs internal solution are promoted by Laplace pressure. With the internal volume decrease, bilayer tension is relaxed and pores closure guided by line tension, minimizing the energetic component of lipid curvature in pore edges. Transient pores model explains experimental results such as mass exchange between internal and external GUVs media, GUVs effluxes, poreslifetime, pores diameters limit and stability of GUV encapsulation after opening and closure of pores.

ASSUNTO(S)

guv line tension poros tensão de bicamada biochemistry lipid bilayer-surface interaction química de superfície bilayer tension tensão de linha transient pores bioquímica guv interação bicamada lipídica-superfície físico-química orgânica

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