Bandages 2.0
In 2019, the Defense Advanced Research Projects Agency, the research arm of the Department of Defense, launched the Bioelectronics for Tissue Regeneration program to encourage scientists to develop a “closed-loop” bandage capable of both monitoring and hastening healing.
Tens of millions in funding has kick-started a flood of innovation since.
“It’s kind of a race to the finish,” said Marco Rolandi, PhD, associate professor of electrical and computer engineering at the University of California Santa Cruz and the principal investigator for a team including engineers, medical doctors, and computer scientists from UC Santa Cruz, UC Davis, and Tufts. “I’ve been amazed and impressed at all the work coming out.”
His team’s goal is to cut healing time in half by using (a) real-time monitoring of how a wound is healing – using indicators like temperature, pH level, oxygen, moisture, glucose, electrical activity, and certain proteins, and (b) appropriate stimulation.
“Every wound is different, so there is no one solution,” said Dr. Isseroff, the team’s clinical lead. “The idea is that it will be able to sense different parameters unique to the wound, use AI to figure out what stage it is in, and provide the right stimulus to kick it out of that stalled stage.”
The team has developed a proof-of-concept prototype: a bandage embedded with a tiny camera that takes pictures and transmits them to a computer algorithm to assess the wound’s progress. Miniaturized battery-powered actuators, or motors, automatically deliver medication.
Phase I trials in rodents went well, Dr. Rolandi said. The team is now testing the bandage on pigs.
Across the globe, other promising developments are underway.
In a scientific paper published in May, researchers at the University of Glasgow described a new “low-cost, environmentally friendly” bandage embedded with light-emitting diodes that use ultraviolet light to kill bacteria – no antibiotics needed. The fabric is stitched with a slim, flexible coil that powers the lights without a battery using wireless power transfer. In lab studies, it eradicated gram-negative bacteria (some of the nastiest bugs) in 6 hours.
Also in May, in the journal Bioactive Materials, a Penn State team detailed a bandage with medicine-injecting microneedles that can halt bleeding immediately after injury. In lab and animal tests, it reduced clotting time from 11.5 minutes to 1.3 minutes and bleeding by 90%.
“With hemorrhaging injuries, it is often the loss of blood – not the injury itself – that causes death,” said study author Amir Sheikhi, PhD, assistant professor of chemical and biomedical engineering at Penn State. “Those 10 minutes could be the difference between life and death.”
Another smart bandage, developed at Northwestern University, Chicago, harmlessly dissolves – electrodes and all – into the body after it is no longer needed, eliminating what can be a painful removal.
Guillermo Ameer, DSc, a study author reporting on the technology in Science Advances, hopes it could be made cheaply and used in developing countries.
“We’d like to create something that you could use in your home, even in a very remote village,” said Dr. Ameer, professor of biomedical engineering at Northwestern.
Timeline for clinical use
These are early days for the smart bandage, scientists say. Most studies have been in rodents and more work is needed to develop human-scale bandages, reduce cost, solve long-term data storage, and ensure material adheres well without irritating the skin.
But Dr. Gurtner is hopeful that some iteration could be used in clinical practice within a few years.
In May, he and colleagues at Stanford (Calif.) University published a paper in Nature Biotechnology describing their smart bandage. It includes a microcontroller unit, a radio antenna, biosensors, and an electrical stimulator all affixed to a rubbery, skin-like polymer (or hydrogel) about the thickness of a single coat of latex paint.
The bandage senses changes in temperature and electrical conductivity as the wound heals, and it gives electrical stimulation to accelerate that healing.
Animals treated with the bandage healed 25% faster, with 50% less scarring.
Electrical currents are already used for wound healing in clinical practice, Dr. Gurtner said. Because the stimulus is already approved and the cost to make the bandage could be low (as little as $10 to $50), he believes it could be ushered through the approval processes relatively quickly.
“Is this the ultimate embodiment of all the bells and whistles that are possible in a smart bandage? No. Not yet,” he said. “But we think it will help people. And right now, that’s good enough.”
A version of this article appeared on WebMD.com.