title: Fluorescence study of lipid bilayer interactions of Eu(III) coordination complexes.
abstract: The interaction between Eu(III) tris-β-diketonato coordination complexes (EC), displaying antitumor activity, and lipid vesicles composed of zwitterionic lipid phosphatidylcholine has been studied using fluorescence spectroscopy techniques. To characterize EC-membrane binding, several fluorescent probes, including pyrene, Prodan and 1,6-diphenyl-1,3,5-hexatriene, have been employed. It has been found that EC display effective partitioning into lipid phase, giving rise to structural modifications of both polar and nonpolar lipid bilayer regions, viz. enhancement of membrane hydration and increase in tightness of lipid chain packing. The fact that EC accumulating in lipid bilayer are incapable of inducing significant disruption of membrane structural integrity creates strong prerequisites for development of liposomal nanocarriers of these potential antitumor drugs. Such a possibility is also corroborated by the observation that EC membrane incorporation does not prevent lipid bilayer partitioning of long-wavelength squaraine dyes which represent promising candidates for visualization of liposome biodistribution.
authors.affiliation: Department of Biological and Medical Physics, V.N. Karazin Kharkov National University, 4 Svobody Sq., Kharkov 61077, Ukraine.
authors.forename: Olga K
authors.initials: OK
authors.lastname: Kutsenko
authors.forename: Valeriya M
authors.initials: VM
authors.lastname: Trusova
authors.forename: Galyna P
authors.initials: GP
authors.lastname: Gorbenko
authors.forename: Todor
authors.initials: T
authors.lastname: Deligeorgiev
authors.forename: Aleksey
authors.initials: A
authors.lastname: Vasilev
authors.forename: Stefka
authors.initials: S
authors.lastname: Kaloianova
authors.forename: Nedyalko
authors.initials: N
authors.lastname: Lesev
mesh_terms: D005063:Europium / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010713:Phosphatidylcholines / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013237:Stereoisomerism
chemical_list: D008051:Lipid Bilayers; D009942:Organometallic Compounds; D010713:Phosphatidylcholines; D005063:Europium