An interdisciplinary team of researchers at McGill University has developed an ultra-strong, environmentally friendly medical glue, or bioadhesive, made from marine waste. The discovery has promising applications for wound care, surgeries, drug delivery, wearable devices and medical implants.

“A glue that can close wounds or make something strongly adhere to the skin is critical for many medical interventions,” says Audrey Moores, a chemistry professor at McGill.

Moores and main co-author Jianyu Li—an associate professor in McGill’s Department of Mechanical Engineering and Canada Research Chair in Tissue Repair and Regeneration—reported their findings in an article recently published in Nature Communications.

The new bioadhesive is composed of chitosan, a chemically modified form of chitin, which is a natural building block found in the exoskeletons of shellfish and certain fungi. The researchers modified the chitosan to have a nanowhisker shape (slender, needle-like shape) using a mechano-chemical process that had been pioneered by Moores and collaborator Edmond Lam in previous studies.

“We chemically manipulate this material to turn it into nanochitosan, which has a range of different properties that we can fine-tune. Using this nanomaterial, we can make nanoglue,” Moores says.

To apply the nanoglue, the researchers used a unique ultrasound technology developed by Li’s research team to penetrate the skin.

“Imagine you have a Band-Aid on your hand. It’s difficult to get it to stay, because your hand moves a lot,” Moores explains. “To get it to stick better, you would need the skin to be permeable to the glue. We used microneedles or ultrasound for that.”

Moores says her team was surprised to find that the ultrasound made the glue stronger. When exposed to sound waves, not only do the nanowhiskers adhere firmly to skin, but they also interlock into a rigid, resilient scaffolding that significantly enhances the glue’s strength and durability. 

“Our initial strategy was to get the nanoglue to stick to the skin, but we discovered that the ultrasound helped build a complex, interconnected network of our nanostructures,” she says.

The researchers say the nanostructure has a range of promising applications not only in health care, but in many engineering contexts. The bioadhesive is also fully biocompatible, even for people with seafood allergies. 

“People with shellfish allergies react to the proteins, not the chitin,” says Moores. “We can remove those during the manufacturing process to avoid allergic reactions. We could also theoretically make a vegan version from fungi.”

The newly developed nanoglue outperforms existing bioadhesives, which often rely on compounds that can be toxic and have poor fatigue resistance when pulled apart repeatedly.

This research was funded by the Natural Sciences and Engineering Research Council of Canada, the National Research Council Ocean program, the Canada Foundation for Innovation, the National Institutes of Health of the United States, the Canada Research Chairs Program, the Centre for Green Chemistry and Catalysis (supported by the Fonds de recherche du Québec – Nature et Technologies), and McGill University. 

This article was adapted and published with permission from McGill University.