Fabrication, characterization, and in vitro biological evaluation of glycyrrhetinic acid ligand-functionalized proliposomes encapsulated docetaxel for treatment of hepatocellular carcinoma

Docetaxel (DTX) is a chemotherapeutic drug extracted from the needles of Taxus baccata with a broad anticancer spectrum that has been widely used for the treatment of various cancers. However, its high hydrophobicity and poor solubility results in low bioavailability that restricted clinical application. To circumvent these challenges, the present investigation was performed to develop DTX proliposomes mediated glycyrrhetinic acid ligand (glycyrrhetinic acid - diaminododecane - cholestrol, GADC) for the treatment of hepatocellular carcinoma. The optimal parameters of liposome formulation were egg phosphatidylcholine/cholesterol mass ratio of 9:1, the ratio of DTX to lipid substance within 1/10, the percent of GADC ligand (8 %), hydration time of 30 min and homogenization time of 10 min. To protect DTX liposomes from external environment during their storage, DTX proliposomes mediated GADC (GADC-DTX-PL), three optimum processing variables, lyoprotectants of sucrose and mannitol, the sucrose/mannitol ratio of 1:1, and the lyoprotectant/egg phosphatidylcholine of 8:1, were obtained after investigation. Under the optimum lyophilization conditions, GADC-DTX-PL was prepared and reconstituted proliposomes were determined to evaluate its physicochemical characterizations. These proliposomes showed that GADC-DTX-PL were spherical particles with an average size of 214.88 ± 11.00 nm, PDI value of 0.23 ± 0.00, zeta potential of –20.04 ±4.94 mV, encapsulation efficiency of 80.58 ± 0.91 %, and drug loading of 7.39 %. In addition, encapsulation of DTX in proliposomal formulation resulted in stable and slow drug release. Furthermore, in vitro bioactivity was evaluated, cytotoxicity effect and apoptosis efficiency of GADC-DTX-PL by HepG2 cells was significantly higher than that of DTX proliposomes without GADC. In the cell cycle assay, the results confirmed that the effect of GADC-DTX-PL regarding the initiation of apoptosis is accompanied with adjustment in the cell cycle progress via generating G2/M arrest. This potential of this novel approach for delivery DTX to hepatocellular cells lies in the ability to combine a targeted ligand of GADC and proliposomes simultaneously. Such formulation of GADC-DTX-PL enhances the selectivity of DTX delivery to hepatocellular cells, thereby improving the efficacy of chemotherapy.