A gecko foot shows its adhesive pads. Photo/David Clements WikipediaResearchers from the MIT Portugal Program and MIT have taken a page from nature and created a gecko-inspired, waterproof bandage that could soon join sutures and staples as a tool in tomorrow’s operating rooms. Scientists have long been fascinated by the gecko’s ability to climb vertically and MIT Portugal and MIT researchers took what they knew of the nanofeatures present in gecko feet – which allows them to stick to vertical surfaces – and have now applied this phenomenon to the surface of a bandage.
“Geckos have nanopillars in their skin and these dramatically increase the surface area and promote surface adhesion [which enables them to climb vertically].” said Lino Ferreira, co-author of a paper recently published about the research in the online version of the Proceedings of the National Academy of Science. Ferreira is a researcher at the Center for Neurosciences and Cell Biology in Coimbra, and Biocant-Biotechnology Innovation Center, Cantanhede,both in Portugal He also contributes in the Bio-engineering Focus Area of the MIT Portugal Program.
Ferreira became involved in this research at MIT as a post-doctoral fellow working with MIT Institute Professor Robert Langer and other members of the team. Langer and Jeff Karp, an instructor of medicine at Boston’s Brigham and Women's Hospital and Harvard Medical School, led the group of researchers. Both Langer and Karp are also faculty members at the Harvard-MIT Division of Health Sciences and Technology (HST).
According to Ferreira, the bandage created by the MIT researchers is different than what is currently being used by doctors.
“It is different because some of the biological glues used in medicine raised problems regarding their biocompatibility ,” he said. He further explained that the current adhesives used are either “soft” or “hard” but this adhesive bandage is tailored to match the tissues it will adhere to.
Using nanopatterning technology, the researchers shaped the biorubber bandage into different hill and valley profiles at nanoscale dimensions. After testing on the intestinal tissue of pigs, they selected the substance that would stick the most and would grip and interlock with the underlying tissue.
Ferreira explained that the adhesive bandage created by the MIT team is coated with a glue-like substance to further enhance the adhesion between the nanopillars and the biological tissues. In addition, the material is biocompatible and biodegradable for use in the medical realm and can be moved with the tissue it is adhered to.
Gecko-like dry adhesives have been in existence since about 2001 but there have been significant challenges to adapt this technology for medical applications given the strict design criteria required.
“We are promoting adhesion inspired by nature and the bandage is degradable so after a certain time it disappears,” said Ferreira.
The resulting bandage “is something we never expect to remove,” said Karp. Because of that difference between the bandage and gecko feet, Karp said, “we're not mimicking the gecko”-which has sticky paws but can still lift them up to walk-“we are inspired by the gecko to create a patterned interface to enhance the surface area of contact and thus the overall strength of adhesion.”
According to Ferreira, the technology is being further developed before it could come to market.
“What we show is proof of concept that this kind of approach might be an alternative approach to the current medical adhesives,” he said.
According to Langer, “This is an exciting example of how nanostructures can be controlled, and in so doing, used to create a new family of adhesives.”
Other MIT authors of the paper are co-first authors Alborz Mahdavi, a former MIT lab technician now at the California Institute of Technology; Jason W. Nichol and Edwin P. Chan, HST postdoctoral fellows; David J.D. Carter and Jeff Borenstein of Draper Laboratory; HST doctoral student Chris Bettinger; and MIT graduate students Siamrut Patanavanich, Loice Chignozha, Eli B. Joseph, Alex Galakatos and Seungpyo Hong, all from the Department of Chemical Engineering. Additional authors are from Massachusetts General Hospital and the University of Basel, Switzerland.
The work was funded by the National Institutes of Health, the Materials Research Science and Engineering Center (MRSEC) program of the National Science Foundation, and the MIT-Portugal program.
This article was written by Michelle Gaseau, MIT Portugal Program with sections written by Elizabeth Dougherty, Harvard-MIT Division of Health Sciences and Technology. Portions of this article were originally published by MIT News Office.