title: The interaction of phospholipid liposomes with bacteria and their use in the delivery of bactericides.
abstract: Liposomes have been prepared from dipalmitoylphosphatidylcholine (DPPC) incorporating the cationic lipids stearylamine (SA), dimethyldioctadecylammonium bromide (DDAB) and dimethylaminoethane carbamoyl cholesterol (DCchol) and the anionic lipids dipalmitoylphosphatidylglycerol (DPPG) and phosphatidylinositol (PI). Their adsorption to biofilms of skin-associated bacteria (Staphylococcus epidermidis and Proteus vulgaris) and oral bacteria (Streptococcus mutans and sanguis) has been investigated as a function of mole % cationic and anionic lipid. Targeting (adsorption) was most effective for the systems DPPC-chol-SA, DPPC-DPPG and DPPC-PI liposomes to S. epidermidis. The effect of extracellular mucopolysaccharide on targeting was investigated for S. epidermidis biofilms. It was found that targeting increased with the level of extracellular mucopolysaccharide for all liposome compositions studied. The delivery of the oil-soluble bactericide Triclosan and the water soluble bactericide chlorhexidine was studied for a number of liposomal compositions. Superior delivery of both bactericides relative to the free bactericide occurred for DPPC-chol-SA liposomes and for Triclosan delivery by DPPC-DPPG and DPPC-PI liposomes targeted to S. epidermidis at low bactericide concentrations. DPPC-chol-SA liposomes were also effective for delivery of Triclosan to S. sanguis biofilms. Double labelling experiments using [14C]-chlorhexidine and [3H]-DPPC suggested that there was exchange between adsorbed liposomes which had delivered bactericide to the biofilm and those in the bulk solution implying a diffusion mechanism for bactericide delivery.
authors.affiliation: School of Biological Sciences, University of Manchester, U.K.
authors.forename: M N
authors.initials: MN
authors.lastname: Jones
authors.forename: Y H
authors.initials: YH
authors.lastname: Song
authors.forename: M
authors.initials: M
authors.lastname: Kaszuba
authors.forename: M D
authors.initials: MD
authors.lastname: Reboiras
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000494:pharmacology*; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects*; D018441:Biofilms / Q000187:drug effects; D002710:Chlorhexidine / Q000008:administration & dosage / Q000494:pharmacology; D004337:Drug Carriers; D006025:Glycosaminoglycans / Q000378:metabolism; D008081:Liposomes / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D010743:Phospholipids / Q000494:pharmacology*; D013212:Staphylococcus epidermidis / Q000187:drug effects; D013295:Streptococcus mutans / Q000187:drug effects; D013298:Streptococcus sanguis / Q000187:drug effects; D014260:Triclosan / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D000891:Anti-Infective Agents, Local; D004337:Drug Carriers; D006025:Glycosaminoglycans; D008081:Liposomes; D010743:Phospholipids; D014260:Triclosan; D002710:Chlorhexidine