"Atomic medicine": a phrase to inspire optimism, awe, or uneasy fear, depending on which decades of the 20th century you spent being young. The word "atomic" has a great deal of weight and a long and changing legacy. As a recent essay at H+ Magazine argues, however, isn't all medicine atomic medicine? We are collections of atoms, and the ills we suffer - aging included - are all, ultimately, caused by atoms being out of place. The medicines of today and all of history are nothing more than very crude and many-times-removed attempts to put errant atoms back where they belong.
Today, when we speak of manipulation, what we seek is manipulation at the atomic level, while working at a sub-atomic resolution. As Drexler and others have pointed out, to date we have worked with atoms only in bulk. We have shaped them with stones, pounded them with hammers, milled them by computer control. The manipulation of individual atoms, in a deft and dexterous fashion, would fulfill a contemporary definition of mastery over fabrication. The field of medicine also falls into the above category.
While the notion that we would one day possess the ability to treat maladies at the molecular level may seem absurd, it should be noted that what I have done while simply writing this article - broadcasting 22,092 copies of a 4 megabyte text - would have required several hours of effort just ten years ago. It took centuries to go from months of work to replicate a single book to minutes, and a decade to go from minutes to fractions of a second. As we master the observation and manipulation of matter, we can look forward to similar changes in medicine.
The leading edge of the age of molecular manufacturing is not far away: a matter of a couple of decades, I'd say.
Systems that can identify, manage and place trillions of molecules accurately are not a pipe dream; after all, we are already surrounded by examples. You, for example, are just such a system, albeit somewhat slow at self-assembly to full size. There's nothing in the laws of physics that jumps out and says we can't do this. It's just a matter of time.
If you have the technology base to build a nanoforge to assemble a brick, then you also have the technology base capable of simultaneously assembling and controlling a hundred million medical nanorobots of arbitrary design and programming. Or an artifical lung better than the real thing, or replacements for immune cells that never get old or worn. You get the idea. A brick is just as complex as any portion of the human body if you have to build the thing molecule by molecule; more fault-tolerant, but just as complex.
The future will becoming increasingly interesting as this century advances: one of many reasons to want to live in good health to see as much of it as possible. That goal will become ever easier as the boundaries of medical technology are pushed outward. In the long run, radical extension of the healthy human life span is a given. It's the short term of the next few decades that will be a challenge, and where every additional effort to accelerate the deployment of the first longevity medicine will save countless lives - perhaps your own included.