In vitro evaluation and in vivo efficacy studies of a liposomal doxorubicin-loaded glycyrretinic acid formulation for the treatment of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC), more than 800.000 cases reported annually, is the most common primary liver cancer globally. Doxorubicin hydrochloride (Dox-HCl) is widely used chemotherapy drug for HCC, but efficacy and tolerability are limited, thus critical to develop delivery systems that can target Dox-HCl to the tumour site. In this study, liver-targeting ligand glycyrrhetinic acid (Gly) was conjugated to polyethylene glycol (PEG) via Steglich reaction and incorporated in liposomes, which were then loaded with Dox-HCl by pH gradient method. The optimal formulation Gly-Peg-Dox-ProLP-F6 showed high Dox-HCl encapsulation capacity (90.0%±1.85%), low particle size (120 ± 3.2 nm). Gly-Peg-Dox-ProLP-F6 formulation demonstrated substantially greater toxicity against HCC cells than commercial Dox-HCl formulation (greater against 1.14, 1.5, 1.24 fold against Hep G2, Mahlavu and Huh-7 cells, respectively), but was 1.86-fold less cytotoxic against non-cancerous cell line AML-12. It increased permeability from apical to basolateral (A-B) approximately 2-fold. Gly-Peg-Dox-ProLP-F6 demonstrated superior antitumor efficacy in mouse liver cancer model as evaluated by IVIS. Isolated mouse liver tissue contained 2.48-fold Dox more than Dox-HCl after administration of Gly-Peg-Dox-ProLP-F6, while accumulation in heart tissue was substantially lower. This Gly-Peg-Dox-ProLP-F6 formulation may improve HCC outcome through superior liver targeting for enhanced tumour toxicity with lower systemic toxicity.