Development of multifunctional polymeric nanoparticles co-loaded with ZnPc and Fe2+ ions for synergetic PDT/CDT therapy

Recently photodynamic therapy (PDT)-based combinational therapeutic approaches have been extensively studied to circumvent the hurdle of tissue hypoxia in solid tumors. In this paper, we reported a facile way to prepare multifunctional nanoparticles (NPs) for synergetic PDT/chemodynamic therapy (CDT). Specifically, photosensitizer ZnPc was firstly loaded inside polymeric NPs by a reprecipitation method, followed by surface coating of Fe2+ ions-chelated polydopamine (PDA) shell, which was polymerized via photo-generated 1O2 from the ZnPc-loaded NPs. The resulting ZnPc@PDA-Fe2+ could not only generate 1O2 upon 660-nm photo-irradiation but also produce OH when exposed to H2O2 through the Fenton reaction. Taking advantage of the ZnPc and Fe2+ co-loaded NPs, in vitro combination therapy was performed on Hela cells. As a result, a higher therapeutic effect was achieved compared to single-modality PDT, corresponding to an improved cell inhibitory rate from 59% to 80%. These results demonstrate that our facilely prepared NPs are promising PDT/CDT nanoagents for efficient cancer therapy.