title: Preparation and in vitro evaluation of anti-VCAM-1-Fab'-conjugated liposomes for the targeted delivery of the poorly water-soluble drug celecoxib.
abstract: When an inflammatory stimulus is given, vascular endothelial cells express various cell adhesion molecules including the vascular cell adhesion molecule (VCAM)-1. In this study, the possibility of specifically delivering anti-inflammatory drugs to activated endothelial cells by utilizing VCAM-1 as a target receptor was explored by loading celecoxib, a selective cyclooxygenase-2 inhibitor, into liposomes coupled to the Fab' fragment against VCAM-1. Anti-VCAM-1-Fab'-conjugated liposomes were prepared by forming an amide linkage between amino groups of Fab' and the carboxylic group of glutaryl-N-phosphatidylethanolamine in liposomes using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide as a cross-linker in the presence of sulpho-N-hydroxysuccinimide. The coupling of Fab' to phospholipids constituting liposomes was confirmed by SDS-PAGE analysis. Under our optimized conjugation conditions, 130.0 µg Fab' was coupled to 1 µmol liposomes. Immunoblotting analysis showed that VCAM-1 protein expression could be induced by incubating human umbilical vein endothelial cells (HUVEC) with TNF-α. Confocal laser microsopy analysis revealed that Fab' conjugation to liposomes selectively increased liposomal uptake in TNF-α-pre-stimulated (VCAM-1-expressed) HUVECs, but not in cells without VCAM-1 expression. The concentration of celecoxib loaded in Fab'-conjugated liposomes was 281.1 ± 29 µg/mL, suggesting that liposomal loading also helped to overcome the limitations in celecoxib administration caused by its poor water solubility. Celecoxib loaded in Fab'-conjugated liposomes inhibited prostaglandin E₂ (PGE₂) production induced by TNF-α-pre-stimulation more efficiently than when loaded in conventional liposomes. Therefore, Fab'-conjugated liposomes served as a drug delivery system with dual functions: targeted delivery and solubilizing capacity.
authors.affiliation: Department of Bioscience and Biotechnology, Sejong University, 98 Gunja-Dong, Gwangjin-gu, Seoul 143-747, Korea.
authors.forename: Dong Il
authors.initials: DI
authors.lastname: Kang
authors.forename: Sukmook
authors.initials: S
authors.lastname: Lee
authors.forename: Jung Tae
authors.initials: JT
authors.lastname: Lee
authors.forename: Byung Je
authors.initials: BJ
authors.lastname: Sung
authors.forename: Ji-Yong
authors.initials: JY
authors.lastname: Yoon
authors.forename: Jin-Ki
authors.initials: JK
authors.lastname: Kim
authors.forename: Junho
authors.initials: J
authors.lastname: Chung
authors.forename: Soo-Jeong
authors.initials: SJ
authors.lastname: Lim
mesh_terms: D000068579:Celecoxib; D002478:Cells, Cultured; D052246:Cyclooxygenase 2 Inhibitors / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D042783:Endothelial Cells / Q000166:cytology* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000737:chemistry* / Q000276:immunology; D008081:Liposomes; D011720:Pyrazoles / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D012995:Solubility; D013449:Sulfonamides / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis; D014471:Umbilical Veins / Q000166:cytology* / Q000378:metabolism; D019010:Vascular Cell Adhesion Molecule-1 / Q000096:biosynthesis / Q000737:chemistry* / Q000276:immunology; D014867:Water / Q000737:chemistry
chemical_list: D052246:Cyclooxygenase 2 Inhibitors; D007140:Immunoglobulin Fab Fragments; D008081:Liposomes; D011720:Pyrazoles; D013449:Sulfonamides; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D014867:Water; D000068579:Celecoxib