A team of engineers led by Tufts University has developed a bandage to actively monitor the condition of chronic wounds, such as diabetic ulcers, and deliver drug treatments to improve the chances of healing. With the idea of assisting the natural healing process, the researchers designed the bandages with heating elements and thermoresponsive drug carriers that can deliver tailored treatments in response to embedded pH and temperature sensors that track infection and inflammation. The bandage, which has been tested in the lab but remains to be assessed in a clinical context, is aimed at transforming bandaging from a passive to a more active treatment. The research was published July 6 in the journal Small.
The pH of a chronic wound is one of the key parameters for monitoring its progress. Normal healing wounds fall within the range of pH 5.5 to 6.5, whereas non-healing infected wounds can have pH well above 6.5. Temperature provides information on the level of inflammation in and around the wound. While the smart bandages in this study combine pH and temperature sensors, flexible sensors for oxygenation — another marker of healing — have also been developed and can be integrated into the bandage, according to Sameer Sonkusale, PhD, professor of electrical and computer engineering at Tufts’ School of Engineering and corresponding co-author for the study.
Inflammation can be tracked not just by heat, but by specific biomarkers as well. A microprocessor reads the data from the sensors and can release drug on demand from its carriers by heating the gel. The entire construct is attached to a transparent medical tape to form a flexible bandage less than 3mm thick. Components were selected to keep the bandage low cost and disposable, except for the microprocessor, which can be re-used. “The smart bandage we created, with pH and temperature sensors and antibiotic drug delivery, is really a prototype for a wide range of possibilities,” said Sonkusale. “One can imagine embedding other sensing components, drugs, and growth factors that treat different conditions in response to different healing markers.”
Mostafalu P, Tamayol A, Rahimi R, et al. “Smart bandage for monitoring and treatment of chronic wounds,” Small, (2018). DOI: 10.1002/smll.201703509.