Co-assembly of doxorubicin and curcumin targeted micelles for synergistic delivery and improving anti-tumor efficacy

Chemotherapeutic drugs have a series of limitations in anti-tumor treatment, mainly including multidrug resistance (MDR) and serious adverse reactions. Co-delivery system with two or more synergistic therapeutic drugs is an effective strategy to settle these limitations. In this study, active tumor-targeted co-delivery micelles (DOX + Cur)-PMs, with two synergistic drugs of a therapeutic drug of doxorubicin (DOX) and a chemosensitizer of curcumin (Cur) co-encapsulated into hyaluronic acid-vitamin E succinate (HA-VES) graft copolymer, were prepared and delivered simultaneously into tumor cells for improving therapeutic effects of DOX. (DOX + Cur)-PMs had uniform particle size, high encapsulation efficacy, sustained release profile and good colloidal stability. In vitro cytotoxicity study, (DOX + Cur)-PMs exerted the strongest cytotoxicity and highest cell apoptosis-inducing activities against DOX-resistant MCF-7/Adr cells. Moreover, (DOX + Cur)-PMs more efficiently internalized into cancer cells and enhanced the cellular uptake of DOX via energy-dependent and caveolae-mediated endocytosis, and significantly reversed MDR effects via CD44 targeting delivery and the synergic effect of released Cur. More importantly, in vivo results illustrated that (DOX + Cur)-PMs not only displayed better tumor accumulation and tumor targeting, and more efficiently inhibited the growth of tumor in 4T1 tumor-bearing mice, but also induced significantly less pathological damage to the cardiac tissue in comparison with free DOX, even DOX-PMs and DOX-PMs + Cur. In summary, this targeted combinational micellar delivery system with DOX and Cur could be a promising vehicle in tumor therapy. (C) 2016 Elsevier B.V. All rights reserved.