title: Preparation of liposomes using an improved supercritical reverse phase evaporation method.
abstract: Liposomes of various phospholipids were prepared using an improved supercritical reverse phase evaporation (ISCRPE) method that utilizes supercritical carbon dioxide (scCO(2)) as an alternative to organic solvents. Using this method, in the absence of any organic solvent including ethanol, the maximum trapping efficiency of glucose reached 36% for 20 mM l-alpha-dioleoylphosphatidylcholine (DOPC), compared to less than 10% using the Bangham method. Liposomes prepared by the ISCRPE method were highly stable for one month at room temperature. Freeze fractured TEM observations, osmotic shrinkage measurements, and DSC measurements revealed that the liposomes prepared by the ISCRPE method are unilamellar vesicles with loosely packed phospholipids. Comparison of nitrogen with scCO(2) revealed that the presence of CO(2) is necessary for the formation of liposomes.
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), Nanotechnology Research Institute, Higashi 1-1-1, Tsukuba Central 5, Tsukuba, Ibaraki 305-8565, Japan. katsuto-otake@aist.go.jp
authors.forename: Katsuto
authors.initials: K
authors.lastname: Otake
authors.forename: Takeshi
authors.initials: T
authors.lastname: Shimomura
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Goto
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Imura
authors.forename: Takeshi
authors.initials: T
authors.lastname: Furuya
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yoda
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Takebayashi
authors.forename: Hideki
authors.initials: H
authors.lastname: Sakai
authors.forename: Masahiko
authors.initials: M
authors.lastname: Abe