Enhancing the anti-glioma therapy of doxorubicin by honokiol with biodegradable self-assembling micelles through multiple evaluations

Combination chemotherapy is an important protocol in glioma therapy and honokiol shows synergistic anticancer effects with doxorubicin. In this paper, honokiol (HK) and doxorubicin (Dox) co-loaded Methoxy poly(ethylene glycol)-poly(ε-caprolactone) (MPEG-PCL) nanoparticles were prepared with a assembly method. The particle size (about 34 nm), morphology, X-ray Powder Diffraction (XRD), in vitro release profile, cytotoxicity and cell proliferation effects were studied in detail. The results indicated that honokiol and doxorubicin could be efficiently loaded into MPEG-PCL nanoparticles simultaneously, and could be released from the micelles in an extended period in vitro. In addition, honokiol and doxorubicin loaded in MPEG-PCL nanoparticles could efficiently suppress glioma cell proliferation and induce cell apoptosis in vitro. Furthermore, Dox-HK-MPEG-PCL micelles inhibited glioma growth more significantly than Dox-MPEG-PCL and HK-MPEG-PCL in both nude mice and zebrafish tumor models. Immunohistochemical analysis indicated that DOX-HK-MPEG-PCL micelles improved Dox's anti-tumor effect by enhancing tumor cell apoptosis, suppressing tumor cell proliferation, and inhibiting angiogenesis. Our data suggest that Dox-HK-MPEG-PCL micelles have the potential to be applied clinically in glioma therapy.