VCAM-1 directed target-sensitive liposomes carrying CCR2 antagonists bind to activated endothelium and reduce adhesion and transmigration of monocytes

Abstract

Chemokines are critically involved in the development of chronic inflammatory-associated diseases such as atherosclerosis. We hypothesised that targeted delivery of compounds to the surface of activated endothelial cells (EC) interferes with chemokine/receptor interaction and thereby efficiently blocks inflammation. We developed PEGylated target-sensitive liposomes (TSL) encapsulating a CCR2 antagonist (Teijin compound 1) coupled with a specific peptide recognized by endothelial VCAM-1 (Vp-TSL-Tj). TSL were characterized for size (by dynamic light scattering), the amount of peptide coupled at the surface of liposomes and Teijin release (by HPLC). We report that Vp-TSL-Tj binds specifically to activated EC in vitro and in vivo, release the entrapped Teijin and prevent the transmigration of monocytes through activated EC. This is the first evidence that nanocarriers transporting and releasing chemokine inhibitors at specific pathological sites reduce the chemokine-dependent inflammatory process.