Dopamine-modified Zero-valent Iron Nanoparticles for Dual-modality Photothermal and Photodynamic Breast Cancer Therapy.

Phototherapy has the advantages of minimal invasion, few side effects, and improved accuracy for cancer therapy. The application of a polydopamine (PDA)-modified nano zero-valent iron (nZVI@PDA) as a new synergistic agent in combination with photodynamic/photothermal (PD/PT) therapy to kill cancer cells is discussed here. The nZVI@PDA offered high light-to-heat conversion and ROS generation efficiency under near-infrared (NIR) irradiation (808 nm), thus leading to irreversible damage to nZVI@PDA-treated MCF-7 cells at low concentration, without inducing apoptosis in normal cells. Irradiation of the nZVI@PDA using an NIR laser led to the conversion of the energy of photons to heat and ROS. Our results showed that the modification of PDA on the surface of nZVI can improve the biocompatibility of the nZVI@PDA. This work integrated the PD and PT effects into a single nanodevice, to afford a highly efficient cancer treatment. Meanwhile, the nZVI@PDA, which combines the advantages of PDA and nZVI, displayed excellent biocompatibility and tumoricidal ability, suggesting its huge potential for future clinical research in cancer therapy.