Sticking Power

New surgical glue could provide alternative for heart procedures

A new waterproof, light-activated adhesive (pink) interacting with collagen tissue (blue). Image: Karp Lab

People who need multiple surgeries for congenital heart defects undergo procedures that are invasive and challenging partly due to an inability to quickly and safely secure devices inside the heart. Sutures take too much time to stitch and can stress fragile heart tissue, and available clinical adhesives are subpar.

The creation of a safe and effective adhesive that can be used internally in the body would help these patients, but researchers trying to develop a glue like this have faced hurdles such as ensuring that it is nontoxic and capable of repelling fluids. Now, a study published by Harvard Medical School researchers in Science Translational Medicine offers a potential breakthrough.

“Current glues are either toxic or easily wash out in the presence of blood or react immediately upon contacting water,” said the study’s senior co-author, Pedro del Nido, HMS William E. Ladd Professor of Child Surgery and 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.”

In a preclinical study, del Nido and colleagues from HMS, Boston Children’s, Brigham and Women’s Hospital and MIT developed a nontoxic biologically inspired adhesive that can rapidly attach biodegradable patches inside a beating heart in the exact place where a hole occurs, such as with ventricular heart defects.

Many creatures in nature have secretions that are viscous and repel water, enabling them to attach under wet and dynamic conditions. Inspired by these examples, the researchers developed a material with these properties that also is biodegradable, elastic and biocompatible. They found that degradable patches secured to the heart with this glue remained attached even at increased heart rates and blood pressure.

“This adhesive platform addresses all of the drawbacks of previous systems in that it works in the presence of blood and moving structures,” said 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,” said co-senior author Jeffrey Karp, HMS associate professor of medicine and co-director of the Center for Regenerative Therapeutics at Brigham and Women’s. “Importantly, we showed that the tissue glue can seal holes in high-pressure dynamic tissues including blood vessels and myocardium.”

Moreover, because the glue’s adhesive abilities are activated with ultraviolet (UV) light, it can provide an on-demand, antibleeding seal within five seconds of UV light application when applied to high-pressure large blood vessels and cardiac wall defects.

The researchers suggested that their waterproof, light-activated adhesive will be useful in reducing the invasiveness of surgical procedures, shortening operating times and improving heart surgery outcomes.

“We are delighted to see the materials we developed being extended to new applications with the potential to greatly improve human life,” said Robert Langer, professor of chemical and biomedical engineering at MIT and a co-author on the study.

The adhesive technology (and other related platforms) has been licensed to a Paris-based start-up company, Gecko Biomedical, which expects to bring the adhesive to market within two to three years.

This work was funded by the National Institutes of Health (HL73647, GM086433 and DE013023), Center for the Integration of Medicine and Innovative Technology (11-315 and W81XWH-09-2-0001) and the Technology Research Program grant of Boston Children's Hospital.

Adapted from Vector, Boston Children's Hospital's science and clinical innovation blog.