In this study, three types of galactosylated cholesterol (i.e., gal-PEG194-chol, gal-PEG1000-chol and gal-PEG2000-chol) were synthesized with one terminal of polyethylene glycol of various chain lengths conjugated to the galactoside moiety, and the other terminal conjugated to the cholesterol.
The galactose-modified liposomes were prepared by thin film-hydration method and doxorubicin (DOX) was loaded to the liposomes by using a ammonium sulfate gradient procedure. The liposomal formulations with galactosylated cholesterol were characterized. Flow cytometry and laser confocal scanning
microscopy analyses showed that the galactose-modified liposomes facilitated the intracellular uptake of liposomes into HepG2 via asialoglycoprotein receptor (ASGP-R) mediated endocytosis. Cytotoxicity assay showed that the cell proliferation inhibition effect of galactose-modified liposomes
was higher than that of the unmodified liposomes. Additionally, the study on frozen section of liver showed that the galactose-modified liposomes enhanced the intracellular uptake of liposomes into hepatocytes. Taken together, these results suggested that liposomes containing such galactosylated
cholesterol (i.e., gal-PEG-chol), had a great potential as drug delivery carriers for hepatocyte-selective targeting.
A polymer of Galactosamine-hyaluronic acid-Vitamin E succinate (Gal-HA-VES) was designed to prepare multifunctional self-assembled micelles for delivery of Norcantharidin (NCTD) to Hepatic carcinoma. NCTD/Gal-HA-VES showed higher cytotoxicity toward CD44-overexpressing MCF-7 cells, MCF-7/Adr cells and ASGP-R overexpressing HepG2 cells, consistent with the enhanced cellular uptake in the selected cell models, indicating Gal-HA-VES micelles were taken up in MCF-7 and HepG2 cells by CD44 and ASGPR receptor mediated endocytosis, respectively. Moreover, the accumulation of Rhodamine 123 demonstrated that Gal-HA-VES has the same action of TPGS as a P -glycoprotein inhibitor blocked drug efflux-related MDR mechanism in resistant MCF-7/Adr cells. The Cell apoptosis assays indicated that NCTD/Gal-HA-VES were more effective in triggering apoptosis, compared with free NCTD or NCTD/HA-VES groups. In vivo study demonstrated that NCTD/Gal-HA-VES group exhibited enhanced tumor targeting and antitumor activity with lower systemic toxicity. Hence NCTD/Gal-HA-VES micelles system can achieve significant tumor targeting and effective treatment of hepatic carcinoma.