Objective      To prepare RGD-R8 modified doxorubicin liposome (RGD-R8-LP-DOX) and to study its activity on breast cancer MCF-7 cells.       Methods      RGD-R8-LP-DOX was prepared by film-ultrasonic dispersion method. The appearance

particle size

Zeta potential

and entrapment efficiency were evaluated. The cellular uptake of RGD-R8-LP by MCF-7 cells in vitro was used to evaluate the targeting efficiency. The anti-proliferation efficiency of RGD-R8-LP-DOX was evaluated by MTT assay.       Results      The particle diameter of the liposome was 115.8±11.5 nm with the Zeta potential of 23.45±4.68 mV. The entrapment efficiency of DOX was 95.6%. The RGD-R8-LP uptaking rate by MCF-7 cells at 4 h was 1.75 times higher than that at 2 h (P0.05). The RGD-R8-LP uptaking rate by MCF-7 cells was 2.1

2.9 and 3.8 times higher than that of R8-LP

RGD-LP and LP

respectively (P0.01). The cell viability of MCF-7 cells treated by RGD-R8-LP-DOX for 24 h was 1.8 times higher than that for 48 h (P0.05). MTT assay demonstrated that after 48 h treatment

the cell viability of MCF-7 cells treated by R8-LP-DOX

RGD-LP-DOX and LP-DOX were 1.6

1.8 and 2.4 times higher than that of RGD-R8-LP-DOX (P0.01)

respectively.       Conclusion      RGD-R8-LP-DOX might serve as a promising breast cancer delivery system of antitumor drugs.