Mice were injected intravenously with DOX·HCL, DOX nanoparticles, targeted DOX nanoparticles, or functional DOX nanoparticles at doses equivalent to 5 mg DOX per kg on days 10, 14, 18, 22, and 26 (PBS was used as a control). The changes in (A, B) tumor volume and (D, E) body weight in the MCF-7- or MCF-7/Adr-bearing Balb/c mice after administration are shown. (C) After 34 days, the tumors were excised from the MCF-7- or MCF-7/Adr-bearing mice in each group. The data are presented as the mean ± SD (n=5). aP<0.05, compared with control; bP<0.05, compared with DOX·HCL; cP<0.05, compared with DOX nanoparticles; dP<0.05, compared with targeted DOX nanoparticles.