Nanomedicine may be defined as the monitoring, repair, construction and control of human biological systems at the molecular level, using engineered nanodevices and nanostructures.

Basic nanostructured materials, engineered enzymes, and the many products of biotechnology will be enormously useful in near-term medical applications. However, the full promise of nanomedicine is unlikely to arrive until after the development of precisely controlled or programmable medical nanomachines and nanorobots.

Such microscopic machines were first hypothesized by the Nobel-winning physicist Richard Feynman in 1959, and later were described at length by K. Eric Drexler in his popular books Engines of Creation (1986) and Unbounding the Future (1991), and in his more recent technical book Nanosystems: Molecular Machinery, Manufacturing, and Computation (1992).

Methods for designing and constructing these devices (or their most important components) are currently being actively pursued by the Institute for Molecular Manufacturing, the Laboratory for Molecular Robotics at the University of Southern California, the Center for Nanoscale Science and Technology at Rice University, the NAS Computational Molecular Nanotechnology Group at NASA/Ames Research Center, and by many other university and government organizations in the United States, Europe, and Japan, and also in the private sector by nanotechnology startup companies such as Zyvex and nanotechnology seed capital firms such as Molecular Manufacturing Enterprises Inc. (MMEI).

Once nanomachines are available, the ultimate dream of every healer, medicine man, and physician throughout recorded history will, at last, become a reality. Programmable and controllable microscale robots comprised of nanoscale parts fabricated to nanometer precision will allow medical doctors to execute curative and reconstructive procedures in the human body at the cellular and molecular levels. Nanomedical physicians of the early 21st century will still make good use of the body’s natural healing powers and homeostatic mechanisms, because, all else equal, those interventions are best that intervene least. But the ability to direct events in a controlled fashion at the cellular level is the key that will unlock the indefinite extension of human health and the expansion of human abilities.