H₂O₂ self-providing synergistic chemodynamic/photothermal therapy using graphene oxide supported zero valence iron...

Chemodynamic therapy (CDT) represents an emerging modality that treats cancer and other malignant diseases by using Fenton or Fenton-like catalysts to decompose hydrogen peroxide (H₂O₂) into toxic hydroxyl radicals (·OH). Despite its great promise, chemodynamic therapy is still limited by low endogenous H₂O₂ levels and lack of highly efficient nanocatalysts. In this study, we have developed multi-functional therapeutic nanocomposites GO-ZVI-GOx (GO = graphene oxide, ZVI = zero valence iron nanoparticles and GOx = glucose oxidase), where the GOx can catalyze the intracellular glucose and self-produce H₂O₂ for enhanced CDT therapy, and the GO is used as a template to avoid the aggregation of ZVI nanoparticles and also as an excellent photo-thermal converter for photothermal therapy under near-infrared (NIR) light. Our results show that this H₂O₂ self-generating nanoplatform can produce substantial amounts of reactive radicals under 808 nm NIR light due to the combinational effect of dual chemodynamic and photothermal therapy, which eventually leads to a significant decrease in cancer cell viability. It is believed that the methodology developed in this study enables conventional chemodynamic therapy to be efficiently improved, and holds great potential for overcoming challenges in many other H₂O₂-dependent cancer therapies.