Fig. 6

The size distribution of Por-PCL-PH-PEG-cRGD polymeric nanoparticles after treated with PBS solution (pH = 7.4) (a), acetate buffer saline solution (pH = 5.0) (b) at different times, respectively. c The release profiles of EPI loaded Por-PCL-PH-PEG-cRGD polymeric nanoparticles in the medium of pH = 7.4 (PBS buffer) and pH = 5.0 (acetate buffer) at 37 °C