Preparation and antitumor activity of mitoxantrone conjugated D-α-tocopherylpolyethylene glycol 1000 succinate prodrug micelle

To improve the theraputic effect of chemotherapeutic drugs, D-α-tocopheryl polyethylene glycol 1000 succinate(TPGS)was employed as a carrier of mitoxantrone(MTO). MTO was successfully conjugated to TPGS via succinic anhydride to prepare TPGS-MTO prodrug. The prodrug was then self-assembled into TPGS-MTO micelle, with the particle size of(25. 61±0. 92)nm, the polydispersity of 0. 22±0. 04 and the Zeta potential of -(3. 98±0. 09)mV. The micelle was homogeneous spheres under the observation of transmission electron microscope(TEM). The drug loading capacity(DLC)was(18. 61±0. 24)% by HPLC. Meanwhile, the particle size of TPGS-MTO micelle remained stable in 24 h. TPGS-MTO showed a controlled drug release profile with only 9. 04% MTO being detected in 24 h in neutral conditions, and faster release was achieved by decreasing pH in media. Cellular uptake experiments showed that micelle was 1. 18 times more effective than parent drug after 6 h incubation on MCF-7 cells. The cytotoxicity of micelle on MCF-7 and MCF-7/MDR cells was detected by MTT, both with anti-tumor activity, especially on MCF-7/MDR cells. In conclusion, TPGS-MTO prodrug micelle could be a potential formulation of higher therapeutic effects and fewer side-effects than MTO itself.