Strong, stretchy surgical glue

After surgery, holding tissue together allows incisions to heal. This closure is often accomplished with stitches or staples, but such materials can further damage tissue, particularly in the case of delicate tissue like lungs. Surgical glue is needed that can seal lung tissue without the need for using sutures or staples first. Although surgical sealants are commercially available, none of them has the right combination of elasticity, shear strength, and adhesion to work well with lung tissue on their own. Nasim Annabi of Northeastern University, Ali Khademhosseini of Harvard Medical School, and coworkers now report a strong and stretchy surgical glue they call MeTro gel that works well with lung tissue (Sci. Transl. Med. 2017, DOI: 10.1126/scitranslmed.aai7466). MeTro gel is a protein-based hydrogel made of human tropoelastin modified with methacryloyl groups that cross-link when activated by ultraviolet light. The material’s adhesive and mechanical properties depend on the amount of protein and the extent of methacryloyl substitution. The strongest and most elastic MeTro gel ­contains 20% protein (weight/volume) with a high degree of methacryloyl substitution. The researchers used the adhesive to seal surgically induced cuts and holes in rat ­arteries and lungs and in pig lungs. Animals treated with the sealant demonstrated no leakage and could breathe normally. The researchers plan to develop new versions of the material that can be cross-linked using visible light. Efforts are under way to commercialize the technology.