pH-Responsive iron-loaded carbonaceous nanoparticles for chemodynamic therapy based on Fenton reaction

Fenton reaction–based chemodynamic therapy is a form of cancer therapy and its efficacy can be significantly improved by facilitating the iron ions involved catalytic reaction. In this work, iron-loaded carbonaceous nanoparticles (CNPs@Fe) with Fenton catalytic activity were fabricated and applied for chemodynamic therapy of cancer. The carbonaceous nanoparticles derived from glucose by a caramelization reaction demonstrated high biocompatibility. Besides, aromatic structures in the carbonaceous nanoparticles prefer accelerating electron transfer to enhance the catalytic decomposition of H2O2, resulting in the formation of highly reactive hydroxyl radicals (•OH). At pH 6.0 (representing the weak acidity in tumor microenvironment), the Fenton catalytic activity of CNPs@Fe for decomposition of H2O2 were 15.3 times higher than that of Fe2+ and 28.3 times higher than that of Fe3O4 by chromogenic reaction. The reasons for the enhancement were explained by analyzing the chemical composition of carbonaceous using high-resolution mass spectra. The developed Fenton agent also demonstrates a significant therapeutic effectiveness and little side effects by in vitro and in vivo anticancer studies. This work has put forward a novel approach to promote generation of reactive oxygen species (ROS) for chemodynamic therapy of cancer.