Synthesis and drug delivery of novel amphiphilic block copolymers containing hydrophobic dehydroabietic moiety.

Well-defined amphiphilic poly(ethylene glycol) and poly(dehydroabietic ethyl methacrylate) block copolymers (PEG-b-PDAEMA) were prepared by atom transfer radical polymerization. The methacrylate block contains a characteristic hydrophobic, biocompatible and economical dehydroabietic moiety. PEG-b-PDAEMA block copolymer micellar nanoparticles loaded with piperlongumine (PLGM) were successfully prepared by a nanoprecipitation method. In vitro and in vivo behaviors of these nanoparticles were thoroughly examined by a set of characterization techniques. Confocal laser scanning microscopy study revealed that these nanoparticles could be well taken up by cancer cells. In vivo near-infrared fluorescence imaging showed that the PLGM-loaded nanoparticles effectively targeted the tumor site by the enhanced permeability and retention (EPR) effect in H22 tumor-bearing mice. The in vivo antitumor examination found that PLGM-loaded nanoparticles exhibited superior efficacy in impeding the tumor growth compared to the commercially available Taxol® and free PLGM formulation. The changes in body weights and blood biochemical profiles were also compared to investigate the safety of PLGM and PEG-b-PDAEMA nanoparticle drug delivery system.