title: Carboxyfluorescein leakage from poly(ethylene glycol)-grafted liposomes induced by the interaction with serum.
abstract: The effects of fetal bovine serum (FBS) on carboxyfluorescein (CF) leakage from poly(ethylene glycol)-grafted liposomes (PEG-liposomes) were investigated. PEG-liposomes were prepared from dipalmitoylphosphatidylcholine (DPPC) and distearoyl-N-monomethoxy poly(ethylene glycol)-succinyl-phosphatidylethanolamines (DSPE-PEG) having PEG molecular weights of 1000, 2000, 3000 and 5000. The presence of FBS dramatically increased CF leakage from liposomes near the gel-liquid crystalline phase transition temperature, but had little effect at lower and higher temperatures. The CF leakage from PEG-liposomes whose molecular weight in PEG units was above 2000 was suppressed compared with that of liposomes without PEG. And, there was hardly any difference in the effect of the PEG molecular weight of the PEG-lipids on CF leakage from PEG-liposomes with FBS when PEG-lipids with a molecular weight in PEG units above 2000 were used. On the other hand, the leakage of CF from liposomes containing 0.145 mol fractions of DSPE-PEG1000 was larger than that of liposomes without PEG. Furthermore, the effects of FBS on the cooperative units of lipid molecules during the gel-liquid crystalline phase transition of liposomes were examined. However, the cooperative units of liposomes with FBS had little change compared with that of liposomes without FBS.
authors.affiliation: College of Pharmacy, Nihon University, Funabashi, Chiba, Japan. khashiza@pha.nihon-u.ac.jp
authors.forename: Kaname
authors.initials: K
authors.lastname: Hashizaki
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Taguchi
authors.forename: Hideki
authors.initials: H
authors.lastname: Sakai
authors.forename: Masahiko
authors.initials: M
authors.lastname: Abe
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Saito
authors.forename: Naotake
authors.initials: N
authors.lastname: Ogawa
mesh_terms: D002152:Calorimetry, Differential Scanning; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004337:Drug Carriers; D005452:Fluoresceins / Q000737:chemistry*; D008051:Lipid Bilayers; D008081:Liposomes; D008567:Membranes, Artificial; D010539:Permeability; D011092:Polyethylene Glycols / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013696:Temperature; D013816:Thermodynamics
chemical_list: D004337:Drug Carriers; D005452:Fluoresceins; D008051:Lipid Bilayers; D008081:Liposomes; D008567:Membranes, Artificial; D012710:Serum Albumin, Bovine; C024098:6-carboxyfluorescein; D011092:Polyethylene Glycols