Trivalent, Gal/GalNAc-containing ligands designed for the asialoglycoprotein receptor

A series of novel, fluorescent ligands designed to bind with high affinity and specificity to the asialoglycoprotein receptor (ASGP-R) has been synthesized and tested on human liver cells. The compounds bear three non-reducing, β-linked Gal or GalNAc moieties linked to flexible spacers for an optimal spatial interaction with the binding site of the ASGP-R. The final constructs were selectively endocytosed by HepG2 cells derived from parenchymal liver cells—the major human liver cell type—in a process that was visualized with the aid of fluorescence microscopy. Furthermore, the internalization was analyzed with flow cytometry, which showed the process to be receptor-mediated and selective. The compounds described in this work could serve as valuable tools for studying hepatic endocytosis, and are suited as carriers for site-specific drug delivery to the liver.

A step closer toward liver-specific drug delivery: The novel, fluorescent-labeled liver targeting device 7 bearing three GalNAc moieties, and designed for efficient interaction with the asialoglycoprotein receptor (ASGP-R), has been synthesized. It evinced efficient uptake by, and high selectivity for human hepatocytes as could be demonstrated using fluorescence microscopy and flow cytometry.Figure optionsDownload as PowerPoint slide