Promoting Early Diagnosis and Precise Therapy of Hepatocellular Carcinoma by Glypican-3-Targeted Synergistic Chemo-Photothermal Theranostics

The specific-targeting approach could promote the specificity of diagnosis and the accuracy of cancer treatment. The choice of a specific-targeting receptor is the key step in this approach. Glypican-3 (GPC3) is an oncofetal proteoglycan anchored on the cell membrane. It is overexpressed even in the early stage of hepatocellular carcinoma (HCC), whereas it shows almost no expression in the healthy adult liver. Therefore, GPC3 may be applied as a specific-targeting receptor for HCC theranostics. In this study, a GPC3 specific-targeting theranostics nanodevice, GPC3 targeting peptide (named G12)-modified liposomes co-loaded with sorafenib (SF) and IR780 iodide (IR780), was developed (GSI-Lip), which aims to realize early diagnosis and precise chemo-photothermal therapy of HCC. SF was the first-line chemotherapy drug for the treatment of HCC. IR780 was used for photothermal therapy and near-infrared fluorescence imaging. The evaluation of early diagnosis verified that early-stage tumors (3.45 ± 0.98 mm3, 2 days after 5 × 105 H22 cells' inoculation in mice) could be clearly detected using GSI-Lip, which was significantly more sensitive than folic acid-modified liposomes ( p < 0.01, 32.90 ± 10.01 mm3, 4 days after 1 × 106 H22 cells' inoculation in mice). The study of the endocytic pathway indicated that specific G12/GPC3 recognition may induce caveolae-mediated endocytosis of GSI-Lip. Notably, the accumulation of GSI-Lip in tumors was significantly increased compared with that observed with folic acid-modified liposomes ( p < 0.01). Specific-targeting endowed the precise antitumor effect of GSI-Lip. GSI-Lip showed a higher antitumor efficacy in comparison with folic acid-modified liposomes (inhibition rate: 90.52% vs 84.22%, respectively; p < 0.01). During a period of 21 days, the synergistic chemo-photothermal therapy (GSI-Lip + laser) exhibited a better antitumor effect versus GSI-Lip without laser (inhibition rate: 94.93% vs 90.52%, respectively; p < 0.01). Overall, GPC3-targeted GSI-Lip promoted the sensitivity and specificity of HCC early diagnosis and achieved synergistic efficacy of chemo-photothermal theranostics, which has potential clinical applications. Furthermore, the present study revealed that a more specific-targeting ligand could further improve the efficacy of theranostics against HCC.