One-step preparation of chitosan-coated cationic liposomes by an improved supercritical reverse-phase evaporation method.
High-pressure carbon dioxide in contact with water dissolves to form carbonic acid, causing a decrease in pH. By use of these characteristics of a CO2/H2O biphasic system, chitosan-coated cationic liposomes of l-alpha-dipalmitoylphosphatidylcholine were successfully prepared by an improved supercritical reverse-phase evaporation (ISCRPE) method. Liposome-chitosan complexes carrying a positive charge were prepared in a single-step procedure without the use of acid or organic solvent, including ethanol. The maximum trapping efficiency of liposomes prepared by the ISCRPE method was 17%, with or without the addition of chitosan, compared to only 2% for liposomes prepared by the Bangham method. Furthermore, the liposomal dispersion was stable at room temperature in a sealed tube for over 30 days.
Otake
Katsuto
K
Nanotechnology Research Institute and Research Institute for Innovation in Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565, Japan. katsuto-otake@aist.go.jp
Shimomura
Takeshi
T
Goto
Toshihiro
T
Imura
Tomohiro
T
Furuya
Takeshi
T
Yoda
Satoshi
S
Takebayashi
Yoshihiro
Y
Sakai
Hideki
H
Abe
Masahiko
M
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry; D002412:Cations; D048271:Chitosan / Q000737:chemistry*; D016503:Drug Delivery Systems; D005614:Freeze Fracturing; D066298:In Vitro Techniques; D008081:Liposomes / Q000737:chemistry / Q000302:isolation & purification*; D008722:Methods; D010316:Particle Size
D002412:Cations; D008081:Liposomes; D015060:1,2-Dipalmitoylphosphatidylcholine; D048271:Chitosan