Nanomedicine, Volume I: Basic Capabilities
© 1999 Robert A. Freitas Jr. All Rights Reserved.
Robert A. Freitas Jr., Nanomedicine, Volume I: Basic Capabilities, Landes Bioscience, Georgetown, TX, 1999
Foreword
The coming ability to carry out targeted medical procedures at the molecular level will bring unprecedented power to the practice of medicine. Within a few short decades we can expect a major revolution in how the human body is healed. Nanomedicine lays the foundations for understanding this revolution and points to where it is taking us.
Throughout science and technology, the race to obtain complete control of the structure of matter is gaining speed and focus. From chemistry to biotechnology, from applied physics to software, increasing resources are being brought to bear on the goal of nanotechnology. The term nanotechnology is used to describe a variety of nanoscale technologies. More precise for present purposes is molecular nanotechnology: the ability to construct objects with atomic-scale control. In lay terms, this is often called "building atom-by-atom"; more accurately, it means being able to bond every atom into a specific, designed location within a larger structure.
It is easy to see that such an ability could lead to, for example, the construction of stronger, more reliable materials, and smaller, faster computer chips. One can also anticipate improved versions of the molecular machines found in nature, similar to today's work in redesigning enzymes. More advanced work should eventually enable the building of molecular machine systems -- micron-scale and even macro-scale systems of novel molecular machines, performing complex operations as do the natural molecular machine systems in living things. Such systems could in principle manufacture large numbers of atomically-precise products -- a process known as molecular manufacturing.
For those with a medical or biological background, a description of such powerful technological abilities at the molecular scale raises questions regarding the potential for applications in living systems, including the human body. The responsible use of technology demands that these interactions be considered in advance of widespread deployment.
For millennia, physicians and their predecessors have worked to aid the human body in its efforts to heal and repair itself. Slowly at first, and with accelerating speed, new methods and instruments have been added to the physician's toolkit -- microsurgical techniques for physically removing problematic tissue and reconfiguring healthy tissue, antibiotics for jamming the molecular machinery of unwanted bacteria, gene chips for rapid identification of genetic sequences.
In most cases, however, physicians must chiefly rely on the body's self-repair capabilities. If these fail, external efforts are hopeless. We cannot today put the component parts of human cells exactly where they should be, and configure them as they should be to form a healthy physiological state. There are no tools for working, precisely and with three-dimensional control, at the molecular level.
Nanomedicine points the way to these advances, which will arm physicians with the most important new tools in medicine since the discovery of antibiotics. The comprehensive development of nanomedicine will dominate medical technology research during the first half of the 21st century, and perhaps beyond.
These are not high-risk predictions, but merely the extension of currently-observable progress in biological and medical research. Advances in understanding living systems in general, and the human body in particular, have arrived at astounding speed over the past three decades and show no signs of slowing down. The completion of the Human Genome Project, once thought almost impossibly ambitious, is now widely regarded as both routine and destined to revolutionize medicine. What was visionary a short time ago is now a minimum baseline expectation.
We can expect this now-familiar pattern to be repeated in the field of nanomedicine. So often a goal, achievable in theory but considered at first to be far too difficult, within a few decades becomes first an active goal, and then an achievement.
Given its revolutionary potential, it is not too soon to examine the goals and potential consequences of nanomedicine. Provided that this work is firmly grounded in today's science -- assuming no new scientific principles, but only the gradual accumulation and application of new data -- we can be confident that our calculations will give reasonable, even conservative, results.
Of course, not all physicians will choose to join in examining the future of medicine. This is not only understandable, but quite reasonable for those who must treat patients today, with the methods available today. Nor is the medical researcher, working to improve today's pharmaceuticals, spurred on by the knowledge that his or her success -- no matter how dramatic -- will eventually be superseded. In both cases, what can be done today, or next year, is the most appropriate focus.
But only a fraction of today's physicians and researchers need look ahead for the entire field of medicine to benefit. Those practitioners who plan to continue their careers into the timeframe when nanomedical developments are expected to arrive -- e.g., younger physicians and researchers, certainly those now in medical and graduate programs -- can incrementally speed the development process, while simultaneously positioning their own work for best effect, if they have a sound idea of where the field of medicine is heading. Those farther along in their careers will be better able to direct research resources today, if the goals of nanomedicine are better understood. Nanomedicine helps us to frame the research issues that must be addressed, and to take better-directed steps on the path toward medical nanotechnology.
Finding the right theoretician to describe the foundations of such a field is difficult. The research requires a high degree of multidisciplinary ability -- not the typical result of academic programs which reward specialization. A multidisciplinary group might serve, but would likely fail to provide the necessary conceptual integration. Rather, the ideal author would be a careful researcher with a broad scientific background -- in particular, one willing and able to tackle a daunting task requiring a decade of concentrated full-time research, constructing a technical exposition that may ultimately span thousands of pages and citations. Robert Freitas brings all these qualities and more to this challenging project.
Some aspects of the book will initially seem controversial. For example, the advent of nanomedicine will redefine the very concept of "disease" (Section 1.2.2). Today's medicine is limited to removing tissue, replacing it with transplants and artificial materials, or helping it repair itself. Current repair techniques require that the tissue be metabolizing and functioning, so inactive or structurally intact but non-functioning tissue is declared "dead." Nanotechnology will let us repair non-functioning tissue, leading us to reexamine the concept of clinical death used in medicine today.
This process of redefinition itself is not new in the field of medicine. It has happened many times before and is central to the goal of extending the frontiers of health into new territory. The advance of the physician's reach down to control at the nanoscale is just one more step on the long evolutionary pathway of medical history.
Also controversial will be the question of how nanomedical techniques should be used. Science discovers natural laws and facts, and technology extends the limits of what was possible with unaltered natural systems. But science and technology do not speak to the issues of what is morally or ethically correct -- they can only help to frame the context of those discussions. Seemingly simple questions such as who is sick and who is well, how much we can do for them, and how much it will cost, require a fundamental understanding of the underlying scientific and technical limits of what is possible. Beyond that, the dialogue must include value judgments, and increasingly -- if the economic and environmental costs can be handled responsibly -- the answers have been provided by the customer, here, the patient.
There is a growing body of humanitarian, religious, and political work in the field of bioethics. A purpose of the present volume is to help frame the issues with a better understanding of what will be possible technically and economically. Thus, it can provide an essential ingredient for responsible ethical discussions while itself staying within the bounds of scientific and engineering analysis.
Leaving aside the substantive ethical debates to come, the technical case presented in Nanomedicine is sure to spark controversy on its own. Those who disagree with the thrust of this book may find segments which, taken out of context, appear unsupported or overstated. This is almost unavoidable in the writing of any book, much less one as ambitious as Nanomedicine. Yet the ideas in this book are supported, as presented in their intended context, and criticisms of them will be most valuable if they keep this context linked to the discussion.
Both the author and publisher of Nanomedicine have graciously agreed to publish the entire book online, accessible at no charge, to better enable debate on, and evolution of, this work. Published critiques, to serve the advance of knowledge, should include a reference to the online location of this material, enabling readers to probe questions in more depth. Online tools now allow third-party annotation of online texts, enabling all concerned parties to contribute to a reasoned discussion of the technical issues raised here. Robert Freitas and I invite readers of this volume to participate in this discussion, with the goal of furthering the evolution of knowledge in the new and vital field of nanomedicine.
Last updated on 16 February 2003