Scheme 1.

Molecular structures of PEG-b-P((LL-g-ss-DOX)-(LL-g-DMA)) and schematic illustration of the multifunctional nanoparticles platform (DA-ss-DT) for in vivo DOX and TRI codelivery and therapy. The polymers and TRI can coassemble to form stable nanoparticles under nature conditions.

Notes: After intravenous administration to mice, the DA-ss-DT can extravasate from leaky tumor vasculature, and the surface charge of DA-ss-DT can change from negative to positive, resulting in quick cellular uptake of cancer cells. After internalization, the redox-sensitive DA-ss-DT nanoparticles disassembled quickly and released the two drugs, thus resulting in efficient tumor inhibited.

Abbreviations: DMA, 2,3-dimethylmaleic anhydride; DOX, doxorubicin; GSH, glutathione; TRI, triptolide.