A Leak-proof, Biocompatible Intestinal Patch

Researchers at Empa have developed a patch that stably seals two sutured pieces of intestine and thus prevents dangerous leaks.

A burst appendix or a life-threatening intestinal volvulus are emergencies that need to be treated by surgeons immediately. However, operations carry risks: highly acidic digestive juices and intestinal bacteria can leak out, causing peritonitis and sepsis.

Sealing sutured tissue with a plaster has already been tried, but the first were not well tolerated or were even toxic. Currently, these plasters are made of biodegradable proteins, which have variable clinical results. These is because they are mainly intended to support the healing process, and dissolve too quickly when in contact with digestive juices and don’t always hold tight. “Leaks after abdominal surgery are still one of the most feared complications today,” explained Empa researcher Inge Herrmann, who is also professor for nanoparticulate systems at ETH Zurich.

Searching for a material that could reliably seal intestinal injuries and surgical wounds, Hermann’s team found a synthetic composite material made up of four acrylic substances that, together, form a chemically stable hydrogel. Additionally, the patch actively cross-links with the intestinal tissue until it is fluid-tight. The quadriga of acrylic acid, methyl acylate, acrylamide and bis-acrylamide works in perfect synergy, as each component conveys a specific feature to the final product: a stable bond to the mucosa, the formation of networks, resistance to digestive juices and hydrophobicity. This new technology is detailed in Advanced Functional Materials.

In lab experiments, the researchers found the polymer system met their expectations. “Adhesion is up to ten times higher than with conventional adhesive materials,” said researcher Alexandre Anthis from Empa’s Particles-Biology Interactions lab in St. Gallen. “Further analysis also showed that our hydrogel can withstand five times the maximum pressure load in the intestine.” The material’s design uses its tailored effect: The rubbery composite selectively reacts with digestive juices that might leak through intestinal wounds, expands and closes all the more tightly. The inexpensive, biocompatible super glue, could thus shorten hospital stays and save healthcare costs, and Anthis is making plans to bring it to market.

Source: Empa