Mn. Jones et al., THE INTERACTION OF PHOSPHOLIPID LIPOSOMES WITH BACTERIA AND THEIR USEIN THE DELIVERY OF BACTERICIDES, Journal of drug targeting., 5(1), 1997, pp. 25-34
Liposomes have been prepared from dipalmitoylphosphatidylcholine (DPPC
) incorporating the cationic lipids stearylamine (SA), dimethyldioctad
ecylammonium bromide (DDAB) and dimethylaminoethane carbamoyl choleste
rol (DCchol) and the anionic lipids dipalmitoylphosphatidylglycerol (D
PPG) and phosphatidylinositol (PI). Their adsorption to biofilms of sk
in-associated bacteria (Staphylococcus epidermidis and Proteus vulgari
s) and oral bacteria (Streptococcus mutans and sanguis) has been inves
tigated as a function of mole % cationic and anionic lipid. Targeting
(adsorption) was most effective for the systems DPPC-chol-SA, DPPC-DPP
G and DPPC-PI liposomes to S. epidermidis. The effect of extracellular
mucopolysaccharide on targeting was investigated for S. epidermiais b
iofilms. It was found that targeting increased with the level of extra
cellular mucopolysaccharide for all liposome compositions studied. The
delivery of the oil-soluble bactericide Triclosan and the water solub
le bactericide chlorhexidine was studied for a number of liposomal com
positions. Superior delivery of both bactericides relative to the free
bactericide occurred for DPPC-chol-SA liposomes and for Triclosan del
ivery by DPPC-DPPG and DPPC-PI liposomes targeted to S. epidermidis at
low bactericide concentrations. DPPC-chol-SA liposomes were also effe
ctive for delivery of Triclosan to S. sanguis biofilms. Double labelli
ng experiments using [C-14]-chlorhexidine and [H-3]-DPPC suggested tha
t there was exchange between adsorbed liposomes which had delivered ba
ctericide to the biofilm and those in the bulk solution implying a dif
fusion mechanism for bactericide delivery.