February 5, 2016, by Brigitte Nerlich

Precision metaphors in a messy biological world

The promises of nanoscience and nanotechnology have been framed by a variety of future oriented metaphors, such as the those of the fantastic voyage or the master builder. The former metaphor has been especially prominent in early reports on the promises of nanomedicine, but it is still in use today. What happens when real breakthroughs are announced? Is this fictional backdrop still used, or do other metaphors become more prominent, especially those used traditionally to talk about the work of medicine? What does this mean for the public understanding of nanomedicine? And what can current developments in gene editing and, what one may call, genomic medicine learn from thinking about these metaphors?

Nano-bullets

I have been interested in the visual and metaphorical framing of nanotechnology for a long time and these questions popped back into my head when I came across an article in The Times by Tom Whipple. The article was entitled “Microcannon firing nanobullets: The future of targeted medicine” (1 February, 2016). The first paragraph of the article reads like this: “The idea of ‘targeting disease’ just got less metaphorical. Scientists have developed microscopic cannons that can be injected into patients and triggered remotely, firing drugs deep into tissue.” Overall, the word (nano)bullet is used 9 times (we even get told about a ‘magic bullet’!) in this 525 word article, and the word (micro)cannon is used 12 times (mostly in quotes from scientists).

This reminded me of an essay I once wrote in which I studied a similar article published in The Times written by Mark Henderson and entitled “New attack on cancer with nano-weapon” (5 November 2009). In this article we don’t hear about bullets but about warheads and smart bombs. Both articles are about ‘targeted’ drug delivery using nanotechnology.

In my 2012 essay I tried to grapple with the way ‘evil metaphors’ (relating to military weapons) are used to talk about improving human health and whether the knowledge they convey is more illusionary than real. A more thorough analysis of this dilemma (evil metaphors for the good of human health) was written two years later by the French philosophers of science Bernadette Bensaude Vincent and Sacha Loeve. Their article, published in NanoEthics, is entitled “Metaphors in Nanomedicine: The Case of Targeted Drug Delivery”. As they point out: “No matter whether you want to heal people or kill them, no matter whether your action is good or bad, the ultimate values are control and precision.” (p. 4)

The two philosophers summarise the framing of precision nano-medicine in the following way: “The missile metaphor, reminiscent of Paul Ehrlich’s ‘magic bullet’, has framed the problem in simple terms: how to deliver the right dose in the right place at the right moment? Chemists, physicists and engineers who design multi-functional devices operating in vitro can think in such terms, as long as the devices are not actually operating through the messy environment of the body.” (p.6)

In their view this metaphor blends out the messiness of the bodily environment into which the bullet, bomb, warhead or missile enters. They therefore suggest a more ecological way of thinking that “requires dealing with nanoparticles as relational entities (defined by their potential for interactions) rather than as stable substances (defined by intrinsic properties)”. (p. 1)

Promises of precision

Since the 1980s, many promises have been made about nanotechnology’s abilities to alleviate human suffering and increase human health. The term ‘nanocapsule’ or rather ‘Nanokapsul’ was first used by Helmut Kopf in 1975 in a thesis on sub-molecular medicine. The term ‘nanomedicine’ seems to have first appeared in print in Eric Drexler et al.’s 1991 book Unbounding the Future. A search of the newspaper database Lexis Nexis reveals that the term was first used in English speaking news in an article for The Philadelphia Inquirer on January 1, 1996 which claimed that “Nanomedicine will use very small mechanisms to target problem spots in our bodies. For example, a tiny bulldozer of sorts would clear out cholesterol, like so much rubble, from arteries, making angioplasty obsolete.”

The first targeted nanoparticle-drug delivery systems were developed in the 1980s, but it has been difficult to create systems that work consistently. However, talk of magic nano-bullets and images of nanobots or of nanosubmarines or, indeed, nanobulldozers scouring the blood vessels or delivering drugs began to proliferate alongside the emergence of nanomedicine, and reached a crescendo in the early 2000s. Such words and associated images, both metaphorical and real, tried to convey the exciting future potentials of nanomedicine for the treatment of common diseases, especially heart disease and cancer – and still do so today.

But is this militaristic framing actually a good framing, both in terms of ethics and in terms of knowledge transfer? The use of militaristic metaphors in science, policy and medicine has attracted growing criticism over the last two decades, with repeated calls for less problematic alternatives, and for greater attention to the possible implications of such framing in policy making and political discourse. Among the charges laid against militaristic metaphors are that they can motivate overly strong actions and can have unforeseen consequences such as the stigmatization of the ill or the promotion of shame and guilt amongst sufferers. Among policymakers and public health officials, military thinking may focus attention only on the physical, see control as central, and may encourage the expenditure of massive resources to achieve ‘targets’.

Yet, the opacity of much scientific and medical knowledge to most non-specialists means that attempts to disseminate it outside its original context in the laboratory and academy unavoidably depend on metaphors. As a well-entrenched cultural resource, military metaphors continue to be a dominant framing device employed by governments, scientists, journalists, and the public, especially in the context of medicine. However, exactly because such metaphors are so compelling, ubiquitous, and seemingly natural, it is all the more important to scrutinize the role they play at the interfaces between science and society and nature and culture.

Off-target effects

Much of medicine is still permeated by war metaphors, from the war against cancer to the battle against antibiotic resistant bacteria. Targeting disease is still a dream dreamed by many and rightly so. However, such precision metaphors might blind us to the complex bodily and social environments in which this precision warfare is being fought – and sometimes we need to be reminded of that complexity and messiness so as not to succumb too quickly to hype and hubris.

There are some lessons here, perhaps, for synthetic biology, but more importantly perhaps for the creation of expectations regarding genome editing, ‘genome surgery’, precision-genetic manipulation and what one might call genomic medicine.

The backdrop to nanoscience has been the story of ‘fantastic voyage’ and breakthroughs in nanomedicine draw on militaristic metaphors. By contrast, the backdrop to genomics has been the ‘book of life‘ (or the map or blueprint) and breakthroughs in genomic medicine employ less militaristic metaphors. But control and precision are still the focus. We hear not so much about bullets but more about precision molecular scissors and erasers, and we see images of knives, spanners and robots with lasers that provide efficient and reliable ways to make precise and targeted changes to the genome of living cells. We also read about ‘guide RNA’ molecules homing in on their target DNA, and so on. Genome editing is said to bring “gene targeting to the masses”.

As Tom Whipple noted, reality is gradually catching up with metaphors, but we are not quite there yet. I agree with Steven Pinker who quipped: “Genetic editing would be a droplet in the maelstrom of naturally churning genomes.” An article on nanomedicine rightly points out: “Targeted drug delivery to tumor sites is associated with highly complex biological, mechanical, chemical and transport phenomena, of which characteristics vary spatiotemporally.” And, of course, in both nanomedicine and genomic medicine there can be off-target effects and (collateral) damage. This means, according to Mark Walport, “that more research is needed. We need to know you are modifying the gene you want to and you aren’t modifying other things as well, whether this is a magic bullet or whether there will be off-target effects.”

Some readings…

Nerlich, B. (2005). From Nautilus to nanobo(a)ts: The visual construction of nanoscience. AZojono: Journal of Nanotechnology Online:

Nerlich, B., Clarke, D.D, Ulph, F. (2007). Risks and benefits of nanotechnology: How young adults perceive possible advances in nanomedicine compared to conventional treatments. Health, Risk and Society, special issue on nanotechnology 9(2), 159-171.

Nerlich, B. (2008). Powered by imagination: Nanobots at the Science Photo Library. Science as Culture 17(3), 269 – 292

Image: Wikimedia Commons

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