Design and characterization of Glypican-3 targeted liposomes with cantharidin encapsulation for hepatocellular carcinoma treatment

Targeted delivery of chemotherapeutic agents to the cancerous cells is of fundamental importance and the key step of the targeted delivery system design is to choice a specific receptor. Glypican-3 (GPC3) is a known cell membrane-associated oncofetal proteoglycan that is specifically up-regulated in the fast-growing hepatocarcinoma cells but rarely expressed in the normal healthy liver. Therefore, GPC3 may be a perfect targeting receptor for delivery treatment of hepatocellular carcinoma (HCC). In the present study, a GPC3 specifictargeting nanoliposomal drug delivery system was constructed with GPC3 targeting peptide (named as L5 peptide) modification and anticancer drug cantharidin encapsulation, which aims to realize cantharidin targeted treatment of liver cancer. In our study, nanoliposome specifically targeting GPC3 receptor was successfully constructed with particle size of 127.9 nm and a spherical shape. The targeted liposomes were stable under 4 degrees C or room temperature for almost 15 days. The drug release from L5-modified liposomes was controlled and delayed. Their targeted delivery properties were characterized by relatively more accumulation in the GPC3 highly expressed HepG2 cells than that of GPC3 lowly expressed Huh-7 cells. The competition results also indicated that the liposomes with L5 peptide modification could competitively bind to GPC3 receptor. Moreover, the liposomes showed colocalization with the lysosome after 3 h incubation. The L5-modified liposomal CTD had an augmented cell growth inhibition and tumor inhibition than that of the free CTD on HepG2 cells and GPC3 highly expressed tumor mice. Our study establishes a new strategy for improving HCC treatment and chemotherapeutic agent targeting delivery.