High schooler invents color-changing sutures to detect infection

A 17-year-old student from Iowa City has found a way to detect an infected surgical wound. Dasia Taylor found a suture thread that when dyed with beet juice, changes color from bright red to dark purple, when a surgical wound becomes infected. Taylor's remarkable invention won several awards at regional science fairs and could potentially change the way surgical wounds are sutured. Taylor first got the idea after learning that the human skin is naturally acidic. This meant the pH value changed when infected and that's when she started researching ways to help reflect that change in surgical wounds. "It literally relies on the most basic principles of pH balance in the body. It’s pretty dope,” said Taylor, reported WSS paper.

She experimented with various fruits and vegetables, which are natural indicators that change color at different pH levels, before zeroing in on beet juice. While healthy skin has a pH value of five, it shoots up to nine when infected. Taylor began working on the project in October 2019. “I found that beets changed color at the perfect pH point,” said Taylor. Bright red beet juice turned dark purple at a pH of nine. “That's perfect for an infected wound. And so, I was like, ‘Oh, okay. So beets is where it's at.’” She was named as one of the 40 finalists in the Regeneron Science Talent Search, the country’s oldest and most prestigious science and math competition for high school seniors, earlier this year in January, according to Smithsonian Magazine.

The primary motivation for her invention was the need to make it available to developing countries where infection from surgical wounds was comparatively higher. According to the World Health Organization, 11 percent of surgical wounds develop an infection in low- and middle-income countries, while only between 2-4 percent develop an infection from surgeries in the U.S. This meant the need for detection of an infected was a bigger problem in developing countries. While researching the subject, Taylor learned that sutures coated with a conductive material could sense the status of a wound by changes in electrical resistance, which would then be transmitted to smartphones or computers of patients and doctors. The only problem was that the "smart sutures" were expensive and thus be accessible only to the rich. It was also a non-starter in developing countries where internet access and mobile technology were lacking. 

One of the issues that bothered Taylor was that up to 20 percent of women who give birth by C-section in some African nations went onto develop surgical site infections. “I've done a lot of racial equity work in my community, I've been a guest speaker at several conferences,” said Taylor. “So when I was presented with this opportunity to do research, I couldn't help but go at it with an equity lens.”

Having found that beets juice was the best dye for the purpose, she now had to find a suture thread that could absorb the dye to reflect the pH value changes. Taylor tested the dye on ten different materials including the standard suture thread. Finally, it was a cotton-polyester blend that seemed to be most suited for the purpose. It changed from bright red to dark purple, before turning light gray after three days. She is now hoping the color-changing sutures designed by her will help detect surgical site infections.

The USP of the current suture thread is that they're easily affordable, they don't cause irritation on the skin, and are strong enough to hold a wound together. Taylor's invention will need to match most of those criteria to replace the existing standard. One issue with the invention is that it cannot detect infection in a wound that happens just below the surface which can be the case in a C-section. Taylor is waiting for her final college admissions results. She will resume work on her project and plans to patent her invention.