54 The Dream of Elixir Vitae would allow the construction of devices with atomic precision capable of a myriad of functions. In  theory,  nanostructures  can  be  built  to  drive  chemical reactions  capable  of  reversing  aging  by  reversing  chemical reactions and damage that occur as we age. The goal would be to build the necessary nanostructures to reverse age-related changes with minimal perturbation. For example, damage to DNA increases with age. Even though it is debatable whether this is a result or a cause of aging, it appears likely that if we could build nanostructures to reverse these changes it could reverse at least some aspects of age-related disease. The body already features several of these nanostructures as part of the DNA repair machinery. Enhancing it with novel nanostruc- tures could help turn the balance of DNA damage versus repair in our favor and thus reverse this form of damage. The appli- cations of nanotechnology are manifold and it is not possible to describe them all, but one possible application would be to design bacteria, viruses, or even stem cells to perform large- scale  gene  therapy  without  being  attacked  by  the  immune system. For example, by taking the viral nanostructures for integrating foreign DNA into host cells and apply them to stem cells. [32] Nanotechnology  holds  great  expectations  and  promises. The greatest problem is that, so far, nanotechnology is almost exclusively theoretical without any clinical or medical trials. Even so, nanomachines aimed at correcting molecular defects for which there is no ‘natural’ tool – e.g., removal of lipofus- cin, also called age-pigment – may be necessary. [33]