Patupilone-loaded poly(L-glutamic acid)-graft-methoxy-poly(ethylene glycol) micelle for oncotherapy

Patupilone, an original natural anti-cancer agent, also known as epothilone B or Epo906, has shown promise for the treatment of a variety of cancers, however, the systematic side effects of patupilone significantly impaired its clinical translation. Herein, patupilone-loaded PLG-g-mPEG micelles were prepared. Patupilone was grafted to a poly(L-glutamic acid)-graft-methoxy-poly(ethylene glycol) (PLG-g-mPEG) by Steglich esterification reaction to give PLG-g-mPEG/Epo906 that could self-assemble to form patupilone-loaded micelles (Epo906-M). The Epo906-M was able to inhibit the proliferation of A549, MCF-7 cancer cells and BEAs-2B cells in vitro. For in vivo treatment of orthotopic xenograft tumor models (MCF-7), the Epo906-M exhibited higher tumor inhibition efficiency with lower side effects as compared with free Epo906. Seventeen percent of the body weight loss appeared in the group treated with free Epo906 of 0.25 mg kg^-1, while the group treated with Epo906-M of 10 mg kg^-1 showed less than ten percent of body weight loss and displayed stronger tumor inhibiting effect. Therefore, the polypeptide-patupilone conjugate has improved potential for oncotherapy.