Super glue for beating hearts

A close-up view of the adhesive (pink) interacting with collagen tissue (blue). Images courtesy of Karp Lab.

Surgeons of all specialties have long sought a safe and effective surgical adhesive or glue that can be used within the body to close wounds or join tissues. The need is particularly great when caring for children with congenital heart defects, where patients undergo multiple invasive procedures and surgeons need to be able to quickly and safely secure devices within the heart.

Sutures are time-consuming to stitch and can cause stress on fragile heart tissue, while the adhesives currently available on the market have several shortcomings. “Current glues are either toxic or easily washout in the presence of blood or react immediately upon contacting water,” says Pedro del Nido, MD, chief of Cardiac Surgery at Boston Children’s Hospital. “The available options also tend to lose their sticking power in the presence of blood or under dynamic conditions, such as in a beating heart.”

A new biocompatible glue developed by researchers from Boston Children’s, Brigham and Women’s Hospital (BWH) and the Massachusetts Institute of Technology (MIT) may overcome all of those obstacles.

The glue—a mixture of glycerol and sebacic acid—grew out of the recognition that many creatures in nature, including slugs, spiders and mites, produce secretions that are viscous and repel water, enabling them to attach under wet and dynamic conditions. Thus inspired, the research team—led by del Nido, Jeffrey Karp, PhD, of BWH, and Robert Langer, ScD, of MIT—developed a material with these properties that also is biodegradable, elastic and biocompatible.

According to preclinical animal data published in Science Translational Medicine1, the glue (dubbed a hydrophobic light-activated adhesive) provides a strong, on-demand, blood-resistant seal after five seconds’ exposure to ultraviolet light. Rather than binding to the top of tissue, the material infiltrates the tissue’s structure, degrading over the course of weeks or months.

The researchers showed that the glue could be applied to large, high-pressure arteries and the heart wall and remain secure. Biodegradable patches adhered with the glue held fast even under increased heart rates and blood pressure.

“This study demonstrated that the adhesive was strong enough to hold tissue and patches onto the heart equivalent to suturing,” says the study’s co-first author Nora Lang, MD, of Boston Children’s Department of Cardiac Surgery. “Also, the adhesive patch is biodegradable and biocompatible, so nothing foreign or toxic stays in the bodies of these patients.”

The researchers note that this waterproof, light-activated adhesive will be useful in reducing the invasiveness of cardiac surgical procedures, as well as operating times, postoperative complications, recovery times and patient discomfort. They also note that the glue could have a long list of applications beyond cardiac surgery, including gastrointestinal surgery and trauma care.

“This adhesive platform addresses all of the drawbacks of previous systems in that it works in the presence of blood and moving structures,” says del Nido. “It should provide the physician with a completely new, much simpler technology and a new paradigm for tissue reconstruction to improve the quality of life of patients following surgical procedures.”

“To our knowledge this is the first demonstration that an adhesive can bond to wet tissues and seal them without being impacted by the presence of blood,” says Karp, of BWH’s Division of Biomedical Engineering. “Importantly, we showed that the tissue glue can seal holes in high-pressure dynamic tissues including blood vessels and myocardium.”

The technology behind the adhesive has been licensed to a start-up company called Gecko Biomedical, based in Paris. The company raised 8 million euros (approximately $11 million) in their Series A financing round and expects to bring the adhesive to the market within two to three years.

Lang N, Pereira MN et al. A blood-resistant surgical glue for minimally invasive repair of vessels and heart defects. Sci Transl Med;6(218):218ra6.