title: Which physical and structural factors of liposome carriers control their drug-loading efficiency?
abstract: The correlation between structural and physical properties of lipid membrane and its drug-loading efficiency were studied. The properties of bilayer were altered by incorporation of several lipidic modifiers: cholesterol, oleic acid, methyl oleate, and pegylated lipid. By using the molecular probe technique it was demonstrated that the membrane properties, such as micropolarity, microviscosity and free volume were considerably changed by incorporation of the modifiers. The partitioning of two different porphyrins between the bulk aqueous phase and the modified liposomes was studied using the fluorescence methods, and liposome-binding constants were determined. It was found that cholesterol reduced the partitioning of both porphyrins into liposomal bilayer. On the contrary, the incorporation of methyl oleate and pegylated lipid causes a pronounced increase in the value of the binding constants of both porphyrins. It was concluded that the free volume rather than hydrophobicity of bilayer is a governing factor in the solute partitioning into lipid bilayers.
authors.affiliation: Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland.
authors.forename: Mariusz
authors.initials: M
authors.lastname: Kepczyński
authors.forename: Kinga
authors.initials: K
authors.lastname: Nawalany
authors.forename: Marta
authors.initials: M
authors.lastname: Kumorek
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Kobierska
authors.forename: Barbara
authors.initials: B
authors.lastname: Jachimska
authors.forename: Maria
authors.initials: M
authors.lastname: Nowakowska
mesh_terms: D016880:Anisotropy; D002626:Chemistry, Pharmaceutical / Q000379:methods; D002627:Chemistry, Physical / Q000379:methods; D004337:Drug Carriers; D007700:Kinetics; D008051:Lipid Bilayers / Q000737:chemistry*; D008055:Lipids / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry*; D008968:Molecular Conformation; D010078:Oxazines / Q000494:pharmacology; D011166:Porphyrins / Q000737:chemistry; D011721:Pyrenes / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D014466:Ultraviolet Rays
chemical_list: D004337:Drug Carriers; D008051:Lipid Bilayers; D008055:Lipids; D008081:Liposomes; D010078:Oxazines; D011166:Porphyrins; D011721:Pyrenes; C044808:nile red