Fig. 4From: Intracellular tracking of drug release from pH-sensitive polymeric nanoparticles via FRET for synergistic chemo-photodynamic therapyThe size and TEM of blank polymeric nanoparticles (a) and EPI-loaded nanoparticles (b). Zeta potential of blank polymeric nanoparticles (c) and EPI-loaded nanoparticles (d)Back to article page