Modified hydrophilic carbon clusters (HCCs), poly(ethylene glycol)-hydrophilic carbon clusters (PEG-HCCs) and similarly structured materials like graphene quantum dots (GQDs), PEGylated GQDs, small molecule antioxidants, and PEGylated small molecule antioxidants. These materials have been modified with an iron chelating moiety, deferoxamine, or a similar chelating moiety. By exploiting common binding sites, the carbon nanostructure facilitates intracellular transport including in mitochondria, reduces oxidative breakdown of the chelator moiety prior to treatment, and reduces both the cause and consequences of metal induced oxidative stress within the body thus providing a novel form of therapy for a range of oxidative and metal-related toxicities. Graphenic materials can be used for the treatment of acute and chronic mitochondrial electron transport chain dysfunction