title: Pharmacokinetic study of the structural components of adenosine diphosphate-encapsulated liposomes coated with fibrinogen γ-chain dodecapeptide as a synthetic platelet substitute.
abstract: Fibrinogen γ-chain (dodecapeptide HHLGGAKQAGDV, H12)-coated, ADP-encapsulated liposomes [H12-(ADP)-liposomes] were developed as a synthetic platelet alternative that specifically accumulates at bleeding sites as the result of interactions with activated platelets via glycoprotein IIb/IIIa and augments platelet aggregation by releasing ADP. The aim of this study is to characterize the pharmacokinetic properties of H12-(ADP)-liposomes and structural components in rats, and to predict the blood retention of H12-(ADP)-liposomes in humans. With use of H12-(ADP)-liposomes in which the encapsulated ADP and liposomal membrane cholesterol were radiolabeled with (14)C and (3)H, respectively, it was found that the time courses for the plasma concentration curves of (14)C and (3)H radioactivity showed that the H12-(ADP)-liposomes remained intact in the blood circulation for up to 24 hours after injection, and were mainly distributed to the liver and spleen. However, the (14)C and (3)H radioactivity of H12-(ADP)-liposomes disappeared from organs within 7 days after injection. The encapsulated ADP was metabolized to allantoin, which is the final metabolite of ADP in rodents, and was mainly eliminated in the urine, whereas the cholesterol was mainly eliminated in feces. In addition, the half-life of the H12-(ADP)-liposomes in humans was predicted to be approximately 96 hours from pharmacokinetic data obtained for mice, rats, and rabbits using an allometric equation. These results suggest that the H12-(ADP)-liposome has potential with proper pharmacokinetic and acceptable biodegradable properties as a synthetic platelet substitute.
authors.affiliation: Department of Biopharmaceutics, Graduate School of Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-honmachi, Kumamoto 862-0973, Japan.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Taguchi
authors.forename: Hayato
authors.initials: H
authors.lastname: Ujihira
authors.forename: Shigeru
authors.initials: S
authors.lastname: Ogaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Watanabe
authors.forename: Atsushi
authors.initials: A
authors.lastname: Fujiyama
authors.forename: Mami
authors.initials: M
authors.lastname: Doi
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Okamura
authors.forename: Shinji
authors.initials: S
authors.lastname: Takeoka
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ikeda
authors.forename: Makoto
authors.initials: M
authors.lastname: Handa
authors.forename: Masaki
authors.initials: M
authors.lastname: Otagiri
authors.forename: Toru
authors.initials: T
authors.lastname: Maruyama
mesh_terms: D000244:Adenosine Diphosphate / Q000008:administration & dosage* / Q000737:chemistry; D000818:Animals; D001802:Blood Substitutes / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D005340:Fibrinogen / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D006801:Humans; D008081:Liposomes; D008297:Male; D051379:Mice; D009842:Oligopeptides / Q000008:administration & dosage*; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley; D014018:Tissue Distribution
chemical_list: D001802:Blood Substitutes; D008081:Liposomes; D009842:Oligopeptides; C027539:fibrinopeptides gamma; D000244:Adenosine Diphosphate; D005340:Fibrinogen