Materials scientists from Nanyang Technological University, Singapore (NTU Singapore) have invented a new type of surgical glue that can help join blood vessels and close wounds faster and may also serve as a platform to deliver pain relief drugs. In a paper published in Elsevier's Biomaterials in July jointly with clinicians from Singapore General Hospital (SGH), the NTU researchers showed that their glue can bond soft tissues including muscle and blood vessels, even when their surfaces are wet.
Named CaproGlu, it is activated by a low dose of ultraviolet (UV) light that cures it in seconds, turning it from a liquid glue into a solid but flexible biorubber - a biocompatible material that can be resorbed by the tissue after a few weeks.
The team showed in animal experiments that blood vessels can be rejoined with just four stitches and a mesh wrapper dipped in CaproGlu, compared to the usual eight stitches that are required for a reliable and unobstructed join. The authors estimate that this will reduce surgery time by 25 per cent, as surgeons spend less time and effort stitching up blood vessels and tissues.
As demonstrated in animal experiments, CaproGlu can also be used to deliver local anaesthetics or pain relief medication to tissues in the body, which may be useful both during and after an operation and would reduce the need for pain relief medication to be administered afterwards.
Unlike current bio-adhesives - which need two chemicals to be mixed prior to use - the CaproGlu is a one-pot liquid gel solution that comes ready-to-use.
Lead authors of the paper, Associate Professor Terry W.J. Steele and Senior Research Fellow Dr Ivan Djordjevic, emphasised that most surgical adhesives available on the market do not work in water or wet environments as found in the human body.
"To make our light-activated glue work on wet tissues, we engineered our glue to first remove water from the surface and thus allow adhesion to the dehydrated surfaces," said Assoc Prof Steele.
"This unique advantage of being able to bond with high strength in a wet environment, as well as being biocompatible, is what makes CaproGlu so suitable to be used in surgery and medical applications."
The adhesion strength of CaproGlu was compared to other commercial bioadhesives on the market and was found to be three to seven times stronger, and is on a par with the shear strength of collagen and muscle tissue found in the human body.