Researchers at MIT recently developed an adhesive tape that allows surgeons to seal internal wounds and that can readily stick to slippery internal surfaces, as a potential replacement for sutures. However, the adhesive worked a little too well, and was difficult to remove or adjust without causing irritation or tissue damage.
Now, the research team has developed a new version of the tape that can be readily detached from the tissue surface by applying a liquid solution. The development makes the tape safer and easier to use, and allows surgeons to remove it once tissue healing has completed or adjust the tape’s position if required.
The tape is conceived as a replacement for internal sutures. “Our goal is to use bioadhesive technologies to replace sutures, which is a thousands-of-years-old wound closure technology without too much innovation,” said Xuanhe Zhao, an MIT researcher involved in the study. “Now we think we have a way to make the next innovation for wound closure.”
The original adhesive included polyacrylic acid and NHS esters, which form long-lasting bonds with the tissue surface. However, these bonds were so strong that it was difficult to remove the tape without causing damage. “Removing the tape could potentially create more of an inflammatory response in tissue, and prolong healing,” said Hyunwoo Yuk, another researcher involved in the study. “It’s a real practical problem.”
To address this, the researchers added a disulfide linker molecule that can be easily severed when exposed to a reducing agent, meaning that the covalent bonds between the adhesive and surface proteins in the tissue can be broken. The resulting tape can be sprayed with a reducing solution and it can then be readily peeled from a tissue surface, regardless of how long it has been in place. Most importantly, the removal is painless and does not cause tissue damage.
“This is like a painless Band-Aid for internal organs,” said Zhao. “You put the adhesive on, and if for any reason you want to take it off, you can do so on-demand, without pain.” Once sprayed, the tape needs to soak in the solution for about five minutes before it can be removed.
“That’s about the time it takes for the solution to diffuse through the tape to the surface where the tape meets the tissue,” said Xiaoyu Chen, a third researcher involved in the study. “At that point, the solution converts this extremely sticky adhesive to just a layer of slippery gel that you can easily peel off.”