Geckos Inspire New Surgical Tape and Glue

Ah, the gecko. Spokes-lizard to save on car insurance. Aquarium-dwelling pet for millions. A terrifying nemesis in the battle against the urban cockroach. And now, the inspiration for a new type of glue for bandages, according to a study released February 19 , 2008 in the online early edition of the Proceedings of the National Academy of Sciences.

A team of researchers at the Massachusetts Institute of Technology developed the waterproof adhesive by studying the footpads of geckos, and how they manage to stick to nearly any surface. What they found were a series of complex nanostructures comprised of hills and valleys, covered with the geckos self-produced glue.

"There is a big need for a tape-based medical adhesive," said Jeff Karp in a press release from MIT. Karp is an instructor of medicine at Brigham and Women's Hospital and Harvard Medical School. Karp is also an instructor at the Harvard-MIT Division of Health Sciences and Technology, along with collaborator Robert Langer.

The team couldn't use the same glue that geckos use - a gecko's adhesive feet don't stick permanently, and don't adhere very well to wet surfaces, at least not for long. Instead, they developed a sugar-analog glue, which could adhere to a variety of tissues - lungs, intestines, heart, bladder, etc. The trick was developing a glue that could be patterned to mimic the nanotopography of the gecko feet that would also be able to stay "stuck" in a wet environment - and not have any adverse side effects for surgical patients.

The "bio-patterning" technique used by the team led by Karp and Langer is the same technology used for making microchips. By creating the complex series of patterns, the level of adherence in rat and pig intestines were shown to double over the stickiness of the glue if laid flat. And adverse side effects were limited to mild inflammation, a common occurrence following surgery.

Other advantages of the new glue-and-patterning technique are the ability to infuse the bandage with drugs, and "tune" the material so it releases the drugs over a specific time period. "This is an exciting example of how nanostructures can be controlled, and in so doing, used to create a new family of adhesives," said Langer.

Nineteen other researchers from MIT, Harvard, the University of Basel (Switzerland) and the University of Coimbra (Cantanhede, Portugal), Massachusetts General Hospital, and Brigham and Women's Hospital (Boston, Massachusetts) were involved in the study.