Porcupine quills inspire MIT's Langer in medical device development

A microscopic view of a synthetic porcupine quill.--courtesy of Karp Lab

The Massachusetts Institute of Technology's Robert Langer--a rock star inventor and entrepreneur in the biotech and medical devices worlds--is at it again. The man who helped inspire 25 new companies is working with co-senior study author Jeffrey Karp at Brigham and Women's Hospital in Boston and others with an eye on porcupine quills as a model for next-generation medical devices. After testing both real and synthetic quills in the lab, the team sees their form and function as a model for next-generation medical adhesives, and also medical needles that penetrate the surface of the skin more easily.

Details are published in the journal Proceedings of the National Academy of Sciences. And the work by Karp, Langer and crew answers long-standing questions: Why North American porcupine quills penetrate tissues so easily, and why it is hard to remove them once they're stuck inside flesh. (The answer: An innovative design.) The animal carries 30,000 defensive quills on its back as a defense mechanism and they are released when attacked by a predator.

They came to their conclusion after testing both natural porcupine quills and replica quills made from molded synthetic polyurethane. What they found: The geometry of a quill allows it to easily jab tissue and then stay there, similar to how a serrated blade functions with the force localized at the tips of the blade's teeth.

"We were most surprised to find that the barbs on quills … reduce the penetration force for easy insertion into tissue, and maximize the holding force to make the quills incredibly difficult to remove," Karp said in a statement.  With only a half-centimeter of penetration, quills keep a strong hold, it turns out, with no bending necessary, the researchers explain.

Based on early work with plastic replicas, the team believes they can develop artificial quills that enable a less painful medical needle, or an adhesive that works better than surgical staples. They plan to proceed with more trials involving their synthetic porcupine quills in a number of potential medical uses.

And with the involvement of Robert Langer--a man who has developed a number of promising companies including MicroCHIPS (implantable drug-delivery microchip) and 2012 Fierce 15 company T2 Biosystems (rapid diagnostics)--we will likely hear more about this work in the near future.

- read the release
- here's the journal abstract
- read the BBC's take

Special Report: T2 Biosystems – 2012 Fierce 15

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MIT's Robert Langer turned out to be a pretty mellow guy