CPP10-targeted photoactivatable MOF nanosystem for combined photodynamic Therapy−Chemotherapy of cancer

The annual prevalence of gastric cancer has increased in recent years. Curcumin (CUR) has shown great potential in the treatment of gastric cancer; however, its low bioavailability and poor efficacy hinder its widespread clinical application. Additionally, CUR has been found to be excellent photosensitizer in photodynamic therapy. In this study, the Fe-based metal-organic framework (MOF) Fe Tetrakis (4-carboxyphenyl) porphyrin (Fe-TCPP，FT) was used as a photosensitizer and mononuclear agent. The natural anti-tumor active ingredient CUR was loaded as both a chemotherapeutic agent and photosensitizer to form the nanoparticles CUR@FT (CF). Finally, a cell-penetrating peptide (CPP10) was modified on the surface of the nanoparticles to construct a drug delivery system (named CPP10-PEG@CUR@FT, CCF) that could actively target tumor cells while exerting a synergistic therapeutic effect of chemotherapy and photodynamic therapy. This can improve the efficacy of CUR as a chemotherapeutic drug or photosensitizer, and the high drug load and pH sensitivity of FT nanoparticles provide an excellent carrier for the efficient delivery of CUR. The polyethene glycol (PEG)-conjugated CPP10 (PEG-CPP10) coating allows nanoparticles to specifically target gastric cancer cells, significantly improving the absorption of nanoparticles in vivo and in vitro and improving biosafety. We evaluated the thermal stability, drug loading capacity, and safety of FT as a drug delivery vehicle. We also assessed the in vitro photodynamic performance and toxicity of various nanoparticles and the targeting and biocompatibility of CPP10-PEG@CUR@FT. CPP10-PEG@CUR@FT could specifically target tumor cells, and its effect on killing gastric cancer cells (MKN45) under light was much stronger than that of free CUR. Its toxicity and side effects to other organs and tissues are low, offering good biosafety. The experimental results showed that FT and CUR exerted synergistic effects on photodynamic therapy and chemotherapy. In summary, our novel CUR-loaded targeted nano drug delivery system offers significant advantages by combining photodynamic therapy and chemotherapy for tumor treatment. This approach introduces a new concept for integrating chemotherapy, photodynamic therapy and targeted drug delivery, potentially providing a new strategy for the clinical treatment of gastric cancer.