Smart sutures could reduce infection risk, simplify post-op care

Surgical site infection (SSI) is one of the most common complications associated with surgery, occurring in around 3% of procedures in Australia, according to the Australian Commission on Safety and Quality in Health Care.

For some procedures, such as vaginal mesh implants to treat prolapse, infection rates can be much higher, leading to a ban on that procedure in 2018 in Australia, say researchers from RMIT who are developing a new antimicrobial suture that could provide an alternative to mesh implants and internal stitches.

Study lead author and Vice Chancellor’s Senior Research Fellow Dr Shadi Houshyar said, “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.”

Targeting drug-resistant bacteria

The suture, being developed in partnership with clinicians, glows in medical imaging. Its properties come from the combination of iodine and tiny nanoparticles called carbon dots that are inherently fluorescent, throughout the material. Attaching iodine to these carbon dots provides them with their strong antimicrobial properties and greater X-ray visibility.

Carbon nano dots can be tailored to create biodegradable stitches or a permanent suture, or even to be adhesive on one side only, where required, Houshyar said.  

The RMIT-led project, involving nano-engineering, biomedical and textile specialists working in partnership with a practising surgeon, used the textile manufacturing facilities at RMIT’s Centre for Materials Innovation and Future Fashion to produce the proof-of-concept material.

In lab tests, the surgical filament was said to be easily visible in CT scans when threaded through samples of chicken meat, even after three weeks. It also showed strong antimicrobial properties, killing 99% of highly drug-resistant bacteria after six hours at body temperature.

“This project opens up a lot of practical solutions for surgeons, which has been our aim from the start and the reason we have involved clinicians in the study.”

Clinical potential

Consultant colorectal surgeon and Professor of Surgery at the University of Melbourne Justin Yeung, who was involved in the study, said the suture addresses a real challenge faced by surgeons in trying to identify the precise anatomical location of internal meshes on CT scans.

“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,” he said.

“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 visualise mesh location accurately on preoperative imaging.” 

Pre-clinical trials

Study co-author from RMIT’s School of Health and Biomedical Sciences Professor Elisa Hill-Yardin said the next steps were pre-clinical trials.  

“While this research is early stage, we believe we’re onto something very promising that could help a lot of people and are really keen to speak with industry partners interested in working with us to take it further,” she said.

“We see potential especially in vaginal mesh implants and similar procedures.”

The project has received seed funding from RMIT and the researchers aim to produce larger suture samples to use in pre-clinical trials.

A sample of the iodine-infused filament in the lab. Credit: RMIT.

Top image caption: Professor Elisa Hill-Yardin, Dr Shadi Houshyar and Professor Justin Yeung inspect a prototype of the filament. Image credit: RMIT.