Instead of sutures, a self-healing antibacterial polymer;
instead of examining the wound, integrated smart monitoring.
It is a staple of science fiction to mock sutures as outdated; after all, the technique has been in use for at least 5,000 years.
Professor Hossam Haick from the Wolfson Department of Chemical Engineering at the Technion–Israel Institute of Technology has finally turned science fiction into reality. His lab succeeded in creating a smart, suture-less dressing that binds the wound together, wards off infection and reports on the wound’s condition directly to the doctors’ computers.
Their study was published in Advanced Materials.
Current surgical procedures entail the surgeon cutting the human body, doing what needs to be done and sewing the wound shut—an invasive procedure that damages surrounding healthy tissue.
Some sutures degrade by themselves (or should degrade) as the wound heals; others need to be manually removed. The dressing is then applied over the wound with medical personnel monitoring the wound by removing the dressing to allow observation for signs of infection such as swelling, redness and heat.
This procedure is painful to the patient and disruptive to healing, but it is unavoidable.
Working with these methods also means that infection is often discovered late since it takes time for visible signs to appear and more time for the inspection to come round and see them.
Even in developed countries, with good sanitation available, about 20 percent of patients develop infections post-surgery, necessitating additional treatment and extending the time to recovery. The figure and consequences are much worse in developing countries.
Prior to beginning a procedure, the dressing —much like a smart Band-Aid— will be applied to the site of the planned incision. The incision will then be made through the dressing.
Following surgery, the two ends of the wound will be brought together and within three seconds, the dressing will bind itself, holding the wound closed, similarly to sutures.
From then, it will be continuously monitoring the wound, tracking the healing process, checking for signs of infection—like changes in temperature, pH and glucose levels—and reporting to the medical personnel’s smartphones or other devices.
The dressing will also itself release antibiotics onto the wound area, preventing infection.
“I was watching a movie on futuristic robotics with my kids late one night,” said Haick, “and I thought: ‘What if we could really make self-repairing sensors?’ ”
Most people discard their late-night cinema-inspired ideas. Not Haick, who the next day after his Eureka moment was researching the subject and making plans.
The first publication about a self-healing sensor came in 2015 (read more about it on the Technion website). At that time, the sensor needed almost 24 hours to repair itself. By 2020, sensors were healing in under a minute (read about the study by Muhammad Khatib, a student in Haick’s lab here), but while it had multiple applications, it was not yet biocompatible—that is, not usable in contact with skin and blood.
Creating a polymer that would be both biocompatible and self-healing was the next step—one that was achieved by postdoctoral fellow Dr. Ning Tang.
The new polymer is structured like a molecular zipper, made from sulfur and nitrogen: The surgeon’s scalpel opens it; then pressed together, it closes and holds fast. Integrated carbon nanotubes provide electric conductivity and the integration of the sensor array. In experiments, wounds closed with the smart dressing healed as fast as those closed with sutures and showed reduced rates of infection.
“It’s a new approach to wound treatment,” said Haick. “We introduce the advances of the fourth industrial revolution—smart interconnected devices—into the day-to-day treatment of patients.”
Professor Hossam Haick is head of the Laboratory for Nanomaterial-based Devices (LNBD) and dean of undergraduate studies at the Technion–Israel Institute of Technology. Dr. Ning Tang served as a postdoctoral fellow in Haick’s laboratory and conducted the study as part of his fellowship. He has now been appointed an associate professor at Shanghai Jiao Tong University.
(JNS).
