Sometimes what may save your life can come from the most unsuspecting places. Then sometimes, what can save your life in one circumstance may be highly risky, or at least technologically premature, in another. Lifeboat Foundation is about making those distinctions regarding emerging technologies and knowing the difference.
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
