Tag Archives: Chaitali Dekiwadia

Glowing suture material could reduce infection and simplify post op monitoring

Reassuringly, you won’t be waking up in the hospital to see your sutures glowing in the dark. On that note, here’s more about the innovation in a February 1, 2023 news item on ScienceDaily,

A new antimicrobial suture material that glows in medical imaging could provide a promising alternative for mesh implants and internal stitches.

Surgical site infections are one of the most common medical infections, occurring in 2 to 4% of patients post-surgery. For some procedures, such as vaginal mesh implants to treat prolapse, infection rates can be higher.

Study lead author and Vice Chancellor’s Senior Research Fellow [RMIT University, Australia], Dr Shadi Houshyar, said their suture was being developed in partnership with clinicians specifically for this type of procedure.

Caption: The filament visible in chicken samples, as seen under CT scan. Credit: RMIT University

A February 1, 2023 RMIT University press release (also on EurekAlert but published January 31, 2023), which originated the news item, provides more context and technical detail about the research,

“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 Houshyar, from the School of Engineering at RMIT University, Australia.

Lab tests on the surgical filament, published in OpenNano, showed it was 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.

Houshyar said the team was not aware of any commercially available suture products that combined these properties.

How they did it

The multidisciplinary team led by RMIT – included nano-engineering, biomedical and textile experts working in partnership with a practicing surgeon – used the university’s cutting-edge textile manufacturing facility to develop their proof-of-concept material.

The suture’s properties come 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 they can also be tuned to various levels of luminosity that easily stand out from surrounding tissue in medical imaging.

Attaching iodine to these carbon dots, meanwhile, provides them with their strong antimicrobial properties and greater X-ray visibility.

Houshyar said carbon nano dots were safe, cheap and easy to produce in the lab from natural ingredients.

“They can be tailored to create biodegradable stitches or a permanent suture, or even to be adhesive on one side only, where required,” she said.

“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 possibilities

Consultant colorectal surgeon and Professor of Surgery at the University of Melbourne, Justin Yeung, was involved in the study. He said it addressed a real challengefaced 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.” 

Next steps

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 at an early stage, we believe we are onto something very promising that could help a lot of people and are really keen to speak with industry partners who are interested in working with us to take it further,” she said.

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

The research team used Australia’s leading university-based textile manufacturing facilities at RMIT’s Centre for Materials Innovation and Future Fashion to produce the proof-of-concept material. They will soon be producing larger suture samples to use in pre-clinical trials, which they have just received seed funding for from RMIT.

Here’s a link to and a citation for the paper,

Smart suture with iodine contrasting nanoparticles for computed tomography by Shadi Houshyar, Hong Yin, Leon Pope, Rumbidzai Zizhou, Chaitali Dekiwadia, Elisa L. Hill-Yardin, Justin MC Yeung, Sabu John, Kate Fox, Nhiem Tran, Ivan Cole, Aaron Elbourne, Vi Khanh Truong, and Adam Truskewycz. OpenNano Volume 9, January 2023, 100120 DOI: https://doi.org/10.1016/j.onano.2022.100120

This paper is open access.

An artificial enzyme uses light to kill bacteria

An April 4, 2018 news item on ScienceDaily announces a light-based approach to killing bacteria,

Researchers from RMIT University [Australia] have developed a new artificial enzyme that uses light to kill bacteria.

The artificial enzymes could one day be used in the fight against infections, and to keep high-risk public spaces like hospitals free of bacteria like E. coli and Golden Staph.

E. coli can cause dysentery and gastroenteritis, while Golden Staph is the major cause of hospital-acquired secondary infections and chronic wound infections.

Made from tiny nanorods — 1000 times smaller than the thickness of the human hair — the “NanoZymes” use visible light to create highly reactive oxygen species that rapidly break down and kill bacteria.

Lead researcher, Professor Vipul Bansal who is an Australian Future Fellow and Director of RMIT’s Sir Ian Potter NanoBioSensing Facility, said the new NanoZymes offer a major cutting edge over nature’s ability to kill bacteria.

Dead bacteria made beautiful,

Caption: A 3-D rendering of dead bacteria after it has come into contact with the NanoZymes.
Credit: Dr. Chaitali Dekiwadia/ RMIT Microscopy and Microanalysis Facility

An April 5, 2018 RMIT University press release (also on EurekAlert but dated April 4, 2018), which originated the news item, expands on the theme,

“For a number of years we have been attempting to develop artificial enzymes that can fight bacteria, while also offering opportunities to control bacterial infections using external ‘triggers’ and ‘stimuli’,” Bansal said. “Now we have finally cracked it.

“Our NanoZymes are artificial enzymes that combine light with moisture to cause a biochemical reaction that produces OH radicals and breaks down bacteria. Nature’s antibacterial activity does not respond to external triggers such as light.

“We have shown that when shined upon with a flash of white light, the activity of our NanoZymes increases by over 20 times, forming holes in bacterial cells and killing them efficiently.

“This next generation of nanomaterials are likely to offer new opportunities in bacteria free surfaces and controlling spread of infections in public hospitals.”

The NanoZymes work in a solution that mimics the fluid in a wound. This solution could be sprayed onto surfaces.

The NanoZymes are also produced as powders to mix with paints, ceramics and other consumer products. This could mean bacteria-free walls and surfaces in hospitals.

Public toilets — places with high levels of bacteria, and in particular E. coli — are also a prime location for the NanoZymes, and the researchers believe their new technology may even have the potential to create self-cleaning toilet bowls.

While the NanoZymes currently use visible light from torches or similar light sources, in the future they could be activated by sunlight.

The researchers have shown that the NanoZymes work in a lab environment. The team is now evaluating the long-term performance of the NanoZymes in consumer products.

“The next step will be to validate the bacteria killing and wound healing ability of these NanoZymes outside of the lab,” Bansal said.

“This NanoZyme technology has huge potential, and we are seeking interest from appropriate industries for joint product development.”

Here’s a link to and a citation for the paper,

Visible-Light-Triggered Reactive-Oxygen-Species-Mediated Antibacterial Activity of Peroxidase-Mimic CuO Nanorods by Md. Nurul Karim, Mandeep Singh, Pabudi Weerathunge, Pengju Bian, Rongkun Zheng, Chaitali Dekiwadia, Taimur Ahmed, Sumeet Walia, Enrico Della Gaspera, Sanjay Singh, Rajesh Ramanathan, and Vipul Bansal. ACS Appl. Nano Mater., Article ASAP DOI: 10.1021/acsanm.8b00153 Publication Date (Web): March 6, 2018

Copyright © 2018 American Chemical Society

This paper is open access.