Researchers at McGill University in Canada have developed bioinspired sutures that mimic the structure of human tendons. The gel-covered sutures are slippery and tough, reducing the damage caused by conventional sutures when used on soft tissues. Interestingly, the gel surface of the sutures may allow for advanced applications such as drug delivery, infection prevention, or even near-infrared imaging to aid suture placement and removal during minimally invasive surgery.
Suturing to close wounds and aid healing is an old technique, with centuries of history, but in all that time sutures haven’t advanced all that much. They are typically much stiffer than the soft tissues they are intended to repair, often resulting in tissue damage that leads to complications and patient discomfort. Additionally, aside from holding a wound together, conventional sutures usually don’t provide any specific functionality to help it heal.
These researchers at McGill University have designed a new type of suture that could help to overcome some of these issues. For inspiration, they looked at tendons in the human body, which are tough but slippery, and so create very little friction as they move past other tissues in the body.
“Our design is inspired by the human body, the endotenon sheath, which is both tough and strong due to its double-network structure,” said Zhenwei Ma, a researcher involved in the study. “It binds collagen fibers together while its elastin network strengthens it.”
The new sutures come with a tough but flexible gel coating that allows them to slide past tissues. To create the new sutures, the researchers coated commercially available braided surgical sutures with an alginate-polyacrylamide hydrogel that has excellent biocompatibility and toughness. The modified sutures demonstrated enhanced mechanical properties, including low stiffness and a slippery surface that reduces tissue friction during use.
Interestingly, the sutures also exhibit significant versatility in terms of advanced applications, and the researchers can incorporate various substances into the gel coating for therapeutic functionality. These include microparticles that respond to pH changes in infected tissue, an antibacterial compound, and fluorescent nanoparticles. The fluorescent nanoparticles allow the sutures to be visualized through near infrared imaging, which could be helpful for suture placement during minimally invasive surgery.
“This technology provides a versatile tool for advanced wound management. We believe it could be used to deliver drugs, prevent infections, or even monitor wounds with near-infrared imaging,” said Jianyu Li, another researcher involved in the study. “The ability to monitor wounds locally and adjust the treatment strategy for better healing is an exciting direction to explore.”