As recently reported on Discovery News, “nanoink” allows for monitoring blood glucose in real-time right under the skin. It does so by using a hydrophobic nanoparticle that changes colors as glucose levels rise and fall. The ink consists of a glucose-detecting molecule, a color changing dye and a molecule that mimics glucose. These three particles continuously swish around inside a 120-nm orb. When glucose is present, the glucose-detecting molecule attaches and glows yellow; if absent, the ink turns orange.

The use of this technology has the advantage over traditional glucose monitoring, of course, in that there is a one-time needle stick for placing the tattoo over the tens of thousands of sticks that a diabetic will need to have over a lifetime.

Another advantage of nanoink tattooing: they can be removed. At least one researcher from Brown University has developed tattoo ink with microencapsulated beads coated with a polymer that when broken with a single laser treatment can simply be expelled from the body, as opposed to multiple laser removal treatments for conventional tattoos.

Diabetes isn’t the only disease candidate for using this technology. The original research involving nanoink tattoos was for monitoring sodium levels in the body, but then it occurred to researchers that glucose could be infinitely more useful as a disease target. The potential uses for “nanoink” as a monitoring technology are almost limitless; for chronic disease monitoring, once the concept can be proven to work for more complex molecules such as glucose, almost any disease could be monitored from heart disease to hyperthyroid to various blood disorders.

According to the researchers at Draper Laboratories studying this technology, the tattoo doesn’t have to be a huge Tweety bird on your ankle or heart on your shoulder; in fact, according to one of the Draper researchers, the tattoo could be just a “few millimeters in size and wouldn’t have to go as deep as a normal tattoo”.
Disease monitoring nano-tattoos, therefore, can be both tiny and painless. Of course, they could be stylish, too, but the nanoink is likely to cost a pretty penny—so before you are imagine a giant tribal arm stamp to monitor your heart disease, you may have to think again.

It may be at least two years before tattoos for monitoring your diabetes are available on the market—so unfortunately, those strips and sticking of fingers and thumbs aren’t going away for diabetics any time soon. But hopefully, someday in the not so distant future, nanotechnology will make the quality of life just a little bit better for diabetics and perhaps improve the disease management for other chronic diseases like heart disease and others as well. In the meantime, you can dream up what you want your “nanoink” tattoo to look like.

Summer Johnson, PhD
Column Editor, Lifeboat Foundation
Executive Managing Editor, The American Journal of Bioethics

MIT scientists from the Institute for Soldier Nanotechnologies announced in January 2007 they had reached an elusive engineering milestone. They had successfully created a synthetic material with the same properties of spider silk.¹ The combination of elasticity and strength of spider silk has been a long sought after target for synthetic manufacturing for improving materials as diverse as packaging, clothing, and medical devices. Using tiny clay disks approximately one billionth of a meter, these nanocrystals combined with rubber polymer create the stretchy but strong polymer nanocomposite.

The use of nanocomposites for the production of packaging materials or clothing seems to be a relatively safe and non-controversial because materials remain outside the body. The United States military has already indicated, according to one source, their desire to use the material for military uniforms and to improve packaging for those lovely-tasting MREs.² In fact, this is why the Army-funded Institute for Soldier Nanotechnology is supporting the research—to develop pliable but tough body armor for soldiers in combat. Moreover, imagine, for example, a garbage bag that could hold an anvil without breaking. The commercial applications may be endless—but there should be real concern regarding the ways in which these materials might be introduced into human bodies.

Although this synthetic spider silk may conjure up images of one day being able to have the capabilities of Peter Parker or unbreakable, super-strength bones, there are some real concerns regarding the potential applications of this technology, particularly for medical purposes. Some have argued that polymer nanocomposite materials could be used as the mother of all Band-Aids or nearly indestructible stents. For hundreds of years, spider silks have been thought to have great potential for wound covering. In general, nanocomposite materials have been heralded for medical applications as diverse as bone grafts to antimicrobial surfaces for medical instruments.

While it would be ideal to have a nanocomposite that is both flexible and tough for use in bone replacements and grafts, the concern is that the in vivo use of these materials might affect the integrity and properties of the material. Moreover, what happens when the nano-stent begins to break down? Would we be able to detect nano-sized clay particles breaking away from a wound cover and rushing under the skin or racing through our blood stream from a nano-stent? Without the ability to monitor the integrity of such a device and given the fact that the composite materials of such interventions are smaller than 1000th the size of a human hair, should we really be moving toward introducing such materials into human bodies? The obvious answer is that without years of clinical trials in humans such clinical applications cannot, and will not, happen.

Although the spider silk synthetic would be ideal for certain applications, medical products ideally would be made out of biodegradable materials. This polymer nanocomposite made of clay is not. Thus, although the MIT scientists have proved the concept of polymer nanocomposites that possess the properties of spider silk, they not conclusively shown that these would be useful for certain biomedical interventions until they have completed human clinical trials which could be 5–10 years in the future.

In the meantime, however, such scientific advances should be applied to those material science problems just like the ones being addressed at the MIT Institute for Soldier Nanotechnologies. Nanomaterials used exterior to the human body or for improving consumer products are an important developments in applied nanotechnologies. They can, and will, improve the lives of service men and women, once their safety and efficacy in real world environments are tested, and eventually improve consumer products as well.

So the next time you see a spider in the corner rather than smashing it into oblivion, you may just want to look at it for a moment and say “Thank you”. (And then run, if you wish.) But stay tuned…medical applications will some day come as well. Some day a spider may just save your life.

Summer Johnson, PhD
Member, Lifeboat Foundation and Nanoethics Columnist for Nanotech-Now.com and Lifeboat Foundation

Executive Managing Editor, The American Journal of Bioethics

1. MIT News. January 17th, 2007. Nanocomposite Research Yields Strong But Stretchy Fibers

2. NanoScienceWorks. MIT Nanocomposite Research Yields Lycra-like Fibers — Strong and Stretchy Material Inspired by Spider Silk