Photon activated biological adhesives in surgery

There are a wide variety of adhesives available for use in surgery, ranging from cyanoacrylates for skin closure to fibrin-based mixtures for use as lung sealants. The development of lightactivated tissue adhesives, commonly known as solders have been undermined by the uncertainty surrounding the end-point for irradiation. A number of methods have been used to define the correct exposure period, from back scatter of light from the tissue/adhesive interface through to thermal feedback systems. However these approaches have not been widely realised in a clinical environment. This paper describes the development of a photochemical approach to light-activated tissue adhesives providing a bifunctional protection that has been shown to generate rapid and strong tissue bonding whilst eliminating the risk of over exposure to damaging radiation using a molecular switch, which protects the underlying tissue from thermal damage.