The adhesives currently used in surgical applications have many shortcomings. They wash away easily and may be toxic or only weakly adhesive. A team led by bioengineer Jeffrey M. Karp and cardiac surgeon Pedro J. del Nido of Harvard Medical School has developed a new surgical glue that avoids these problems (Sci. Transl. Med. 2014, DOI: 10.1126/scitranslmed.3006557). The new adhesive is made from a viscous, spreadable precursor to poly(glycerol sebacate acrylate). Exposing the material to ultraviolet light activates cross-linking between the acrylate groups to form a flexible polymer film. The precursor doesn’t immediately harden in blood and can adhere to wet tissue. Because the glue doesn’t polymerize or adhere until activated, patches coated with it can be repositioned as necessary until they are exposed to UV light. The adhesive is strong enough to withstand the high pressure in blood vessels and to close defects in blood vessels on its own. The researchers used the glue to attach prosthetic patches to repair heart and blood vessel defects in rats and pigs.