Look to the lizard

You wouldn't think gecko feet and medical adhesives would necessarily come together, but that's where researchers disagree. Scientists from around the world are developing a tough biodegradable polymer adhesive for use in medicine by studying how geckos stick to vertical surfaces.

The adhesive is a polymer that has been modified to mimic the nanotopography of gecko feet-the lay of the land of the underside of the gecko's sucker toes. The surface of a gecko's foot is made up of tiny "nanoscale pillars." The stickiness is thanks to the ratio of the diameter of the pillar's tip to the pillar's pitch and diameter. In other words, by changing the direction and sizes of the bases and tips of the nano-sized sticky points, scientists can get this adhesive bandage to adhere extremely well, even in cases of a lot of twisting and moving-or deformation of the tissue. After scientists slapped on a layer of dextran to the microscopic pillars, the stickiness significantly increased on their test surfaces: in vitro pig intestine tissue and rat abdominal tissue.

Ultimately, scientists think the gecko-inspired adhesive will be used for sealing wounds and replacing or augmenting sutures and staples. They also hope to find a way for the adhesive to deliver drugs or growth factors to promote healing.