MIT surgical adhesive detaches on demand

MIT created a surgical adhesive last year that was able to quickly and firmly stick to wet surfaces like biological tissues. The double-sided adhesive tape was shown to be usable to seal rips and tears in lungs and intestines in seconds. MIT scientists have further developed that adhesive so that it can detach from the underlying tissue without causing any damage.

To detach the adhesive, the researchers applied liquid solution allowing the new version of the adhesive to be peeled away like a slippery gel if it needs to be adjusted during surgery. They can also be removed once the tissue has healed. One of the MIT researchers called it a "painless Band-Aid for internal organs."

The original adhesive was designed out of a biocompatible polymer that included polyacrylic acid, which is a highly absorbent material commonly used in diapers and pharmaceuticals able to soak up water. The material quickly forms weak hydrogen bonds with the tissue surface.

The scientists reinforce those bonds by embedding the material with NHS esters, which are chemical groups that form stronger, longer-lasting bonds with proteins on a tissue's surface. The team found that the chemical bonds gave the tape very strong grip but were difficult to break. That meant difficult removal and potential harm to organs underneath.

The make the adhesive detachable. The team tweaked the adhesive itself using a new disulfide linker molecule that can be placed between covalent bonds with the tissue surface protein. That particular molecule has strong bonds that can be easily separated if exposed to a particular reducing agent. The team then researched suitable reducing agents that were biocompatible and able to sever the bonds. The search landed on glutathione or baking soda. Once applied, the adhesive could be peeled from the tissue in about five minutes with no damage.