Preparation and in vitro evaluation of anti-VCAM-1-Fab'-conjugated liposomes for the targeted delivery of the poorly water-soluble drug celecoxib

J Microencapsul. 2011;28(3):220-7. doi: 10.3109/02652048.2011.552989.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Celecoxib
  • Cells, Cultured
  • Cyclooxygenase 2 Inhibitors / chemistry
  • Cyclooxygenase 2 Inhibitors / pharmacokinetics
  • Cyclooxygenase 2 Inhibitors / pharmacology
  • Endothelial Cells / cytology*
  • Endothelial Cells / metabolism
  • Gene Expression Regulation / drug effects
  • Humans
  • Immunoglobulin Fab Fragments / chemistry*
  • Immunoglobulin Fab Fragments / immunology
  • Liposomes
  • Pyrazoles* / chemistry
  • Pyrazoles* / pharmacokinetics
  • Pyrazoles* / pharmacology
  • Solubility
  • Sulfonamides* / chemistry
  • Sulfonamides* / pharmacokinetics
  • Sulfonamides* / pharmacology
  • Tumor Necrosis Factor-alpha / biosynthesis
  • Umbilical Veins / cytology*
  • Umbilical Veins / metabolism
  • Vascular Cell Adhesion Molecule-1 / biosynthesis
  • Vascular Cell Adhesion Molecule-1 / chemistry*
  • Vascular Cell Adhesion Molecule-1 / immunology
  • Water / chemistry

Substances

  • Cyclooxygenase 2 Inhibitors
  • Immunoglobulin Fab Fragments
  • Liposomes
  • Pyrazoles
  • Sulfonamides
  • Tumor Necrosis Factor-alpha
  • Vascular Cell Adhesion Molecule-1
  • Water
  • Celecoxib