Solid supported vesicles for bactericide delivery

doi:10.3109/08982100009031101

2008-09-28

PRE

Tesca C. Bennett *

Jonathan E. Creeth

Malcolm N. Jones

DOI：10.3109/08982100009031101

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摘要

En 中文

Cationic and anionic liposomes have been prepared by extrusion from dipalmitoylphosphatidylcholine (DPPC) and its mixtures with cholesterol and dimethyldioctadecyltrimethylammonium bromide (DDAB) and with phosphatidylinositol (PI) respectively covering a range of composition from 0 to 19 mole % DDAB and PI. The adsorption of liposomal lipid from the liposome dispersion onto particles of silica and titanium dioxide in suspension has been studied as a function of liposome composition and concentration. The adsorption isotherms have been fitted using a Langmuir equation from which the binding constants and maximum surface coverage were obtained. The Gibbs energies of adsorption for the cationic liposomes were on average -61.0 +/- 2.1 kJ mol(-1) (on silica) and -50.6 +/- 2.9 kJ mol(-1) (on titanium dioxide). On average saturation adsorption is equivalent to 3 to 10 lipid monolayers on silica and 3 to 7 on titanium dioxide. Using liposomes encapsulating D-glucose it is demonstrated that there is almost no release of glucose on adsorption of the lipid, indicating that the liposomes are adsorbed intact to form a liposome monolayer on the particle surfaces. Adsorption of intact liposomes to form a close-packed liposome monolayer of solid supported vesicles (SSV) is shown to be equivalent to on average 7.0 +/- 0.2 phospholipid monolayers. The SSVs are shown to have increased stability to disruption by surfactants and when carrying the oil-soluble bactericide, Triclosan(TM), to be capable of inhibiting the growth of oral bacteria from immobilised biofilms.

Keyword:

liposome adsorption

solid supported vesicles

silica

titanium dioxide

Triclosan (TM)

oral bacteria