title: Real-time trafficking of PEGylated liposomes in the rodent focal brain ischemia analyzed by positron emission tomography.
abstract: Aliposomal drug delivery system was previously applied to ischemic brain model rats for the treatment of brain ischemia, and we observed that 100-nm-sized liposomes could extravasate and accumulate in the ischemic brain region even when cerebral blood flow was markedly reduced in permanent middle cerebral artery occlusion (p-MCAO) model rats. In the present study, we investigated the real-time cerebral distribution of polyethylene glycol (PEG)-modified liposomes (PEGliposomes) labeled with 1-[18F]fluoro-3,6-dioxatetracosane in p-MCAO rats by positron emission tomography (PET). [18F]-Labeled PEG-liposomes were intravenously injected into p-MCAO rats 1 h after the onset of occlusion, and then a PET scan was performed for 2 h. The PET scan showed that the signal intensity of [18F] gradually increased in the ischemic region despite the drastic reduction in cerebral perfusion, suggesting that PEG-liposomes had accumulated in and around the ischemic region. Therefore,drug delivery to the ischemic region by use of liposomes would be possible under ischemic conditions, and a liposomal drug delivery system could be a promising strategy for protecting the ischemic brain from damage before recovery from ischemia.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Fukuta
authors.forename: Takayuki
authors.initials: T
authors.lastname: Ishii
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Asai
authors.forename: Genki
authors.initials: G
authors.lastname: Nakamura
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: Akihiko
authors.initials: A
authors.lastname: Sato
authors.forename: Yurika
authors.initials: Y
authors.lastname: Agato
authors.forename: Kosuke
authors.initials: K
authors.lastname: Shimizu
authors.forename: Shuji
authors.initials: S
authors.lastname: Akai
authors.forename: Dai
authors.initials: D
authors.lastname: Fukumoto
authors.forename: Norihiro
authors.initials: N
authors.lastname: Harada
authors.forename: Hideo
authors.initials: H
authors.lastname: Tsukada
authors.forename: Akira T
authors.initials: AT
authors.lastname: Kawaguchi
authors.forename: Naoto
authors.initials: N
authors.lastname: Oku
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D016503:Drug Delivery Systems; D020244:Infarction, Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000378:metabolism; D008081:Liposomes / Q000493:pharmacokinetics* / Q000627:therapeutic use; D008297:Male; D011092:Polyethylene Glycols / Q000493:pharmacokinetics* / Q000627:therapeutic use; D049268:Positron-Emission Tomography; D051381:Rats; D017208:Rats, Wistar
chemical_list: D008081:Liposomes; D011092:Polyethylene Glycols