Antibacterial ‘Smart Stitches’ Reveal Location of Sutured Area in CT Scans

By HospiMedica International staff writers
Posted on 10 Feb 2023

Image: The filament visible in chicken samples, as seen under CT scan (Photo courtesy of RMIT University)

Surgical site infections are among the most common medical infections and occur in 2 to 4% of patients following surgery, although the infection rate can be much higher for some procedures, such as vaginal mesh implants to treat prolapse, infection. Now, a new antimicrobial suture material that glows in medical imaging offers a promising alternative for mesh implants and internal stitches.

A multidisciplinary research team led by RMIT University (Melbourne, Australia) that included nano-engineering, biomedical and textile experts working in partnership with a practicing surgeon has developed the proof-of-concept material. In lab tests conducted by the team, the surgical filament threaded through samples of chicken meat was easily visible in CT scans, even after three weeks. The surgical filament also demonstrated strong antimicrobial properties by killing 99% of highly drug-resistant bacteria after six hours at body temperature.

The suture gains its properties from the combination of iodine and tiny nanoparticles, called carbon dots, throughout the material. Carbon dots are inherently fluorescent, due to their particular wavelength, but can also be tuned to different levels of luminosity that easily stand out from surrounding tissue in medical imaging. By attaching iodine to these carbon dots, they gain strong antimicrobial properties and greater X-ray visibility.

According to the researchers, carbon nano dots are safe, cheap and easy to produce in the lab from natural ingredients. The researchers believe that it addresses a serious challenge faced by surgeons in attempting to identify the precise anatomical location of internal meshes on CT scans. The researchers will now conduct pre-clinical trials for which they will produce larger suture samples.

“Our smart surgical sutures can play an important role in preventing infection and monitoring patient recovery and the proof-of-concept material we’ve developed has several important properties that make it an exciting candidate for this,” said Dr. Shadi Houshyar, study lead author and Vice Chancellor’s Senior Research Fellow from RMIT University’s School of Engineering.

“This mesh will enable us to help with improved identification of the causes of symptoms, reduce the incidence of mesh infections and will help with precise preoperative planning, if there is a need to surgically remove this mesh,” said consultant colorectal surgeon and Professor of Surgery at the University of Melbourne, Justin Yeung, who was involved in the study. “It has the potential to improve surgery outcomes and improve quality of life for a huge proportion of women, if used as vaginal mesh for example, by reducing the need for infected mesh removal. It may also significantly reduce surgery duration and increase surgical accuracy in general through the ability to visualize mesh location accurately on preoperative imaging.”

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RMIT University