|A microscopic view of a synthetic porcupine quill.--Courtesy of Karp Lab|
The clever thing about North American porcupine quills is that they slip through the skin easily but they are really tough to get out. This is useful for the porcupine, not so good for the victim. But this defense mechanism could also have a use in drug delivery, for example, by leading to less painful or more robust needles that do less damage as they slip through the skin.
Porcupines have about 30,000 quills of up to 10 cm long, and they have tiny backward-facing barbs on the last 4 mm of the quills. These barbs not only mean that the quills snag on the way out, but also make them slide into the skin more easily, needing around half the pressure needed for quills with no barbs. The barbs act like the serrations on a sharp kitchen knife, cutting cleanly and easily through a tomato.
Creating a needle that penetrates as easily as a porcupine quill but isn't as difficult to remove could mean a shot that is much less painful.
"For needles, we envision we could use 'swell-able' or degradable barbs, to enable easy penetration and easy removal," Jeffrey Karp of Harvard Medical School and Brigham and Women's Hospital told BBC News.
The research could also lead to better adhesives in surgery as replacements for stitches, staples or medical-grade superglue. These would be faster to use and especially useful in emergencies or in gastrointestinal surgery.