The anti-tumor effect of folate-targeted liposome microbubbles loaded with oridonin as ultrasound-triggered tumor-targeted therapeutic carrier system.

In this study, folate receptor (FR) targeted liposome microbubbles loaded with oridonin (ORI) (F-LMB-ORI), liposome loaded with ORI (L-ORI) and liposome microbubbles loaded with ORI (LMB-ORI) were prepared. In vitro release properties, cellular uptake and cytotoxicity in HepG-2 cells as well as in vivo antitumor effects in HepG-2 cells tumor-bearing mice of F-LMB-ORI, L-ORI and LMB-ORI were evaluated upon ultrasound exposure. Results showed cytotoxicity assay on F-LMB-ORI gave IC50 of 0.508 ± 0.018 µmol/mL on HepG-2 cells and LMB-ORI; L-ORI gave IC50 of 2.424 ± 0.116 µmol/mL, 3.031 ± 0.122 µmol/mL in vitro, respectively. These drug delivery carriers were able to control the release of ORI. F-LMB-ORI exhibited higher binding to HepG-2 cells in comparison to LMB-ORI and L-ORI. F-LMB-ORI improved antitumor activity of ORI obviously in comparison to L-ORI, LMB-ORI under in vivo ultrasound. After the treatment for 14 d, the tumor inhibition ratio for F-LMB-ORI (the dose of ORI: 1.5 × 10-2 g·kg-1, once a day) was 87.6%, obviously higher than that of LMB-ORI group, L-ORI group and free ORI (the dose of ORI: 1.5 × 10-2 g·kg-1, once a day) which were 71.5%, 64.3% and 43.4%, respectively.