A method of uncoupling mitochondria in a subject including administering nanotubes to the subject in a therapeutically effective amount, wherein the nanotubes are self-rectifying is provided. A method of decreasing reactive oxygen species and decreasing detrimental loading of Ca2+ into mitochondria is provided, including administering a pharmaceutically effective amount of nanotubes into the subject. A method of reducing weight, treating cancer, reducing the effects of traumatic brain injury, or reducing the effects of ageing, in a subject including administering a pharmaceutically effective amount of nanotubes into the subject is also provided.