Preparation and Evaluation of Doxorubicin-Loaded Micelles Based on Glycyrrhetinic Acid Modified Gelatin Conjugates for Targeting Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most prevalent fatal diseases and the incidence of HCC is increasing worldwide. Polymeric micelles with targeting groups have drawn great attention as carriers for drug delivery in HCC therapy. Herein, novel glycyrrhetinic acid modified gelatin (GA-GEL) conjugates with three substitution degrees were synthesized and characterized. Doxorubicin (DOX) was applied as a model drug. DOX-loaded GA-GEL (DOX/GA-GEL) micelles were prepared by an emulsion-solvent evaporation method. The mean diameters of DOX/GA-GEL micelles were in the range of 195–235 nm. The encapsulation efficiency of DOX/GA-GEL micelles was 63.6%–96.2%, and the loading content was 8.3%–12.5%. Drug release from DOX-loaded micelles exhibited a biphasic manner in phosphate buffer solution (PBS) at pH 7.4. DOX/GA-GEL could be efficiently accumulated into human liver cancer HepG2 cells. The IC 50 values of DOX/GA-GEL-2 and DOX·HCl in HepG2 cells were 0.33 and 0.66 μ g/mL, respectively. In vivo imaging analysis demonstrated that the fluorescence signals of DiR-labeled GA-GEL-2 micelles were mainly distributed in liver and H22 orthotopic tumor, indicating that GA-GEL had the liver-targeting activity. Compared to DOX·HCl, DOX/GA-GEL-2 exhibited better antitumor activity in H22 orthotopic mice. Therefore, these results indicated that GA-GEL could be used as carrier of hydrophobic drug for targeting HCC.