Sheets of elastic, sticky polymers could replace sutures and provide long-term drug delivery.
Geckos are living, breathing party tricks: their sticky feet let them walk along ceilings and up and down walls. Institute Professor Robert Langer and Jeffrey Karp, a bioengineer in the Harvard-MIT Division of Health Sciences, have designed a stretchy, biodegradable tape inspired by geckos’ feet. The tape could replace surgical sutures and staples; it could also be used to deliver drugs to organs, including the heart.
Based on a new “biorubber,” the MIT tape mimics the flexible, hairlike nanoscale structures that expand the surface area of gecko toes. Gecko-inspired adhesives aren’t new, but this one incorporates a chemical glue and is stronger; it’s also the first made for medical purposes and proved safe in animals.
Karp says the tape would have advantages over sutures and staples in closing wounds. Not only can those tools puncture tissue and cause damage that leads to necrosis, but they must be very carefully placed along an incision: “You have to realign the tissue with each stitch,” Karp says. The tape could be laid down in one motion, potentially shortening patients’ time in surgery. It could also help doctors during laparoscopic surgeries, which are performed through a small incision. “It’s difficult to tie knots in small places,” says Karp. “You could have the tape unfold and apply it through the [laparoscopic] needle.”
Karp says the tape might also be used to reinforce sutures and staples used when a segment of the gastrointestinal tract is removed during gastric bypass surgery. “There are low complication rates, but leaks are catastrophic,” he says. The tape could release drugs that promote healing as it seals the incision.
Finally, the material could be made into drug delivery patches that could stick even to tissues that stretch and contract. “It’s elastic, so it should withstand the mechanical forces of the heart,” says Karp. After heart attacks, patients often have regions of damaged tissue that don’t get enough oxygen. This can lead to heart failure. Injecting a stem-cell-attracting factor encourages tissue regeneration, but sticking needles into the heart is dangerous. Karp says a patch of medical tape might deliver these factors at lower risk.
Karp says his team will now work with doctors to identify the applications that have the most to gain from the technology, adapt the tape’s mechanical properties and rate of degradation accordingly, and work toward clinical trials.