NANOTECHNOLOGY

Imagine a world in which manufacturing and medical treatments take place solely at a molecular level, a world in which human bodies are reengineered to include more durable tissues or to reverse past injuries. These are some of the dreams motivating scientists and engineers pursuing the field of nanotechnology. As the name implies, nanotechnology involves the engineering or manipulation of matter, and life, at nanometer scale, that is, one-billionth of a meter. (Ten hydrogen atoms side by side span 1 nanometer; the DNA molecule is 2.3 nanometers across). If feats such as those mentioned above were possible, then the structures of the human body and the current tools of humankind could be significantly altered. In recent years many governments around the world, including the United States with its National Nanotechnology Initiative, and scores of academic centers and corporations have committed increasing support for developing nanotechnology programs (Glapa).

The Birth of an Idea

The idea behind nanotechnology originated with Nobel laureate Richard Feynman in a speech he gave to the American Physical Society in 1959. He described the development of tools for molecular engineering, whereby things would be built molecule by molecule. He proposed, as a challenge to his colleagues, the writing of the entire Encyclopedia Britannica on the head of a pin. His startling claim was that this sort of task would not require a new understanding of physics and was completely compatible with what scientists already understood about the nature of force and matter. Little was done in response to the Feynman challenge until the publication of works by K. Eric Drexler in the 1980s and 1990s. Drexler demonstrated the feasibility of such manipulation from an engineering perspective and provided a vision for the possible benefits of such technologies.

What Could Nanotechnology Do?

The list of potential uses of nanotechnology continues to expand. The primary focus of research at this point concerns miniaturization of electronic components (Bachtold et al.; Hornbaker et al.), but nanoscale materials may dramatically improve the durability of materials used in machinery and could result in less polluting and more efficient production methods. The U.S. military has a significant interest in nanotechnology and has created the Institute for Soldier Nanotechnologies (ISN). Among the initial aims of the ISN is to create stealth garments (and coatings) that are difficult to see or detect, are highly durable, and provide increased protection from penetrating objects. The institute aims to develop devices to rapidly and accurately detect biological or chemical weapon attacks. The ISN is also interested in using nanotechnology to help seamlessly integrate electronic devices into the human nervous system—creating the cyborg soldier.

There are many possible medical uses of microscopic, subcellular machines. Medical applications of nanotechnology include rational drug design; devices specifically targeting and destroying tumor cells (McDevitt et al.) or infectious agents; in vivo devices for the manufacture and release of drugs and for tissue engineering or reengineering at the site of need; early detection or monitoring devices; in vitro diagnostic tools amounting to a laboratory on a chip (Park, Taton, and Mirkin); devices to clear atherosclerotic lesions in coronary or cerebral arteries; and biomimetic nanostructures to repair or replace DNA or other organelles. Nanotechnology might be used to provide artificial replacements for red blood cells and platelets (Freitas, 1996), to augment or repair interaction between neurons in the brain, to improve biocompatibility and the interface between brain tissue and cybernetic devices, and to develop more durable prosthetic devices or implants (Drexler, 1986; Drexler and Peterson; Freitas, 1999; Crandell; BECON). Such tools have also been envisioned to provide new means of cosmetic enhancement, such as controlling weight, changing hair or skin color, removing unwanted hair, or producing new hair simulations (Crawford). Also, some of the potential therapeutic uses previously listed would lead to more effective treatment of life's greatest killers, such as cancer, infectious disease, and vascular disease, leading in turn to greatly enhanced human lifespans.

One other possible project to arise from nanotechnology has become the focus of a rigorous debate among members of the nanocognoscenti. This controversial device is the self-replicating assembler, which was first envisioned by Drexler in 1986. The assembler is in essence a form of artificial life, for not only would it manipulate its environment on a molecular or atomic level, as other nanomachines would, but it would also be coded and designed to replicate itself, potentially making endless copies of itself. Alternatively, nanomachines could be designed to function more as viruses, using the mechanisms in other living cells to help duplicate constituent parts and assemble them into a new machine. While it is beyond the scope of this entry to detail the elements of the debate between those who contend such devices can and will be developed and those who adamantly claim that Drexlerian assemblers are a physical impossibility, the assembler is an excellent starting point for the discussion of the ethical aspects of nanotechnology.

Ethical Issues

The ethical issues of nanotechnology can be grouped into five categories:

1. the challenges of prospective technology assessment and regulation;
2. environmental impact of nanotechnologies;
3. issues of justice and access to the goods and services that might accrue from nanotechnology;
4. the ethical and social implications of increased longevity that might result from medical nanotechnology; and
5. the issues of augmentation or enhancement of human attributes and function.

Accidents, Abuses, and Regulation

The vision for medical uses of nanotechnology is exciting, and if only a portion of the proposed devices prove possible, nanotechnology may benefit many thousands of patients. Any device that can operate on the subcellular level, however, can just as easily be designed to destroy as to repair or heal. In fact, it will be far easier to develop devices that kill. One of the first applications of medical nanotechnology involves a device that can target and destroy cancer cells. Despite the arguments over the feasibility of creating assemblers, it is not a far stretch to envision nanoscale weapons that could be borne on the winds or delivered through the water or food supply. Even if not self-replicating, such devices, with appropriate targeting or with the ability to synthesize toxic substances once inside the host could prove to be quite lethal or disabling. If assemblers were ever created, with the ability to self-replicate like bacteria, then the level of personal or environmental harm could be substantial.

Concern over the potential military or terrorist use of such technology, which could ultimately be fairly cheap to produce, and thus impossible to sufficiently regulate once in existence, has led some (even within the technology community) to contend that the only safe way to proceed is to choose not to develop the tools and methods of nanotechnology at all (Joy). In this view, the only way to prevent the potential devastating harms of a technology, or the consequences of malicious use of knowledge and technology, is to not develop the technology, or acquire the knowledge, in the first place. Arguments of this type, however, assume the burden of proving:

1. that the projected abilities of the device in question are possible to achieve;
2. that the feared harms cannot be prevented, controlled, or mitigated to an acceptable degree;
3. that it is feasible to achieve universal consensus that the area of technology and/or knowledge in question should not be pursued; and
4. that such a prohibition can be sufficiently policed.

In the case of the first issue, it seems very likely that biological nanodevices will be developed, most likely using a so-called bottom-up approach. That is, existing biological molecules and organelles will be used as models for creating tools to achieve the desired function, or these "natural" materials will be used in new ways. An example of this is a project that involved the conversion of the ATPase molecule, ubiquitous in living cells, into a molecular motor (Soong et al.). Therefore, because the development of functioning biomechanical nanodevices is highly probable, it is morally imperative to prospectively evaluate the possible impact of these technologies as they are being developed, so that appropriate safeguards can be implemented to protect against accidents, unanticipated consequences, or inappropriate uses of the technology.

While many disagree with Joy's conclusions, his concerns for the potential harms that autonomous technology could produce are legitimate. It is his response to the second issue, the likely ability or inability to control or protect against foreseeable or unforeseeable harms, that has led to the most dissent. Concerns have been raised that autonomous, self-replicating assemblers could escape control, and/or mutate, in such a way as to destroy life and the environment on a massive, cataclysmic scale. This is Drexler's (1986) socalled "gray goo scenario." In a 2000 article, however, Robert A. Freitas Jr. calculated that this nightmarish scenario is unlikely because of the ability to detect the activity of such biovorous devices early on and to neutralize them. In the early days of recombinant DNA research, there were many concerns about releasing lethal plagues into the environment, quite similar to a number of the concerns being voiced about nanotechnology. Yet the scientific community responded strongly and wisely to the challenges of DNA research, establishing procedural safeguards that remain in use (Krimsky; Fredrickson) and that serve as a model for developing and containing potentially harmful technologies.

Pursuing a similar course of prospective risk assessment and guideline development, the Foresight Institute published the "Foresight Guidelines on Molecular Nanotechnology" in 2000. The guidelines remain voluntary recommendations, but they could be used as a framework for formal regulation and licensing of biologically active nanodevices. Some of the recommended design principles include: (1) dependence on a single fuel source or cofactor that does not exist in the natural environment; (2) requiring constant signaling from an external source for the device to continue functioning; and/or (3) programming termination times (similar to apoptosis in living cells). While it is hopeful that all responsible researchers and engineers would embrace suggestions such as these, there will need to be formal regulation with serious economic, licensure, and punitive penalties for failure to comply. Additionally, the granting of licenses to perform research in nonlaboratory settings or to market nanodevices, as well as the awarding of patents, should be contingent upon proof of the ability to detect and destroy the devices in both in vitro and in vivo settings.

The idea that humankind could reach universal agreement to limit or forbid certain areas of research is naive, and very unlikely to happen, particularly when the field of knowledge in question may lead to vast improvements in health, lifespan, productivity, and so on. Even if consensus could be achieved, policing such restrictions will be essentially impossible. The force of curiosity, as well as the stubborn human heart's universal propensity to rebel against restriction, will ensure that the research will indeed take place, just not as rapidly as it might have otherwise. Rather it is wiser to direct the development of the technology in such a way as to prepare defenses concurrently along with the devices themselves. It is only in this way that humankind and individual societies can be prepared to meet the threats of terrorism, accidents, and other calamities resulting from the creation and/or abuse of a particular technology.

The Nano-Improved Human

As mentioned above, medical nanotechnology may provide exciting tools for healing injured tissue, repairing DNA, and treating neoplastic and infectious diseases, as well as for cosmetic applications. It is conceivable that some nanodevices may also be used to strengthen normal tissue; to manipulate certain DNA strands to alter traits; or to augment mental function, either via enhanced electronic interfaces at the cellular level or by direct stimulation of certain neural pathways. These latter possibilities immediately bring up difficult questions.

Should such uses of bionanotechnology be permitted? If they should, should the medical profession be involved with nonhealing, elective augmentation, and if not, then who should? Should people be allowed to use health insurance to cover the cost of such interventions? How can just access be ensured otherwise? Such augmentations, if successful, would create significant differentials in performance in the workplace, physical abilities, and so on. Consequently, the wealthy would get stronger and wealthier, further increasing their advantage over those who might not be able to afford the technology in question.

In his 1999 book Nanomedicine, Freitas suggested that nanotechnology, and by implication other potentially augmenting technologies, requires a new concept of disease that transcends the classic model of disordered function. He calls this new model the volitional normative model of disease, and he described it as follows:

Disease is characterized not just as the failure of "optimal" functioning, but rather as the failure of either (a) "optimal" functioning or (b) "desired" functioning. Thus disease may result from:

1. failure to correctly specify desired bodily function (specification error by the patient),
2. flawed biological program design that doesn't meet the specifications (programming design error),
3. flawed execution of the biological program (execution error),
4. external interference by disease agents with the design or execution of the biological program (exogenous error), or
5. traumatic injury or accident (structural failure). (Freitas, 1999, p. 20)

While encompassing traditional understandings of disease, this model additionally takes disease out of the context of an objective pathophysiological assessment and turns disease into whatever the patient defines it to be. Any limitation or undesired trait may now be declared disease. Though ostensibly continuing the contemporary trend of patient self-determination to a new level, this approach is fraught with both danger and injustice. To declare that a condition is disease imposes a moral claim that services ought to be rendered for its modification, elimination, or amelioration. The balance between beneficence (the obligation to do good) and nonmaleficence (the obligation to prevent harm) may be inappropriately tipped to what the patient desires, rather than needs. Physicians would be reduced to agents of wish fulfillment and to technicians, rather than remaining healers. These issues already exist to some degree in the area of cosmetic surgery but will expand to involve most other areas of medicine as well. Further, claims to "treatment" would unjustly deplete healthcare resources and funds, potentially depriving those in real need of legitimate healing.

Conclusion

Nanotechnology offers exciting new tools for materials processing, more powerful and integrated electronic devices, and new medical therapies. Nanodevices, however, may also become instruments of harm, and they require prospective regulation and engineering to prevent both foreseeable and unforeseeable negative consequences. Nanodevices join a number of other developing technologies that offer the potential to alter or augment the human body. A prospective, widespread discussion of the implications of these technologies for the human species, the profession of medicine, and the world's communities should occur as soon as possible.

c. christopher hook

SEE ALSO: Biomedical Engineering; Cybernetics; Enhancement Uses of Medical Technology; Human Dignity; Transhumanism and Posthumanism

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