Chronic skin wounds from burns, diabetes, and other medical conditions can overwhelm the regenerative capabilities of the skin and often lead to persistent infections and amputations. Non-healing chronic wounds are a significant medical problem. Patients are often older, non-ambulatory, and limited in their ability to provide self-care, yet non-healing wounds are typically treated in an outpatient setting or at home.
With the idea of providing an assist to the natural healing process, smart bandages were developed 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 smart bandages could provide real-time monitoring and delivery of treatment with limited intervention from the patient or caregivers.
The prototype bandage actively monitors the condition of chronic wounds and delivers appropriate drug treatments to improve the chances of healing. While the lab-tested bandages remain to be assessed in a clinical context, they could transform bandaging from a traditionally passive treatment into a more active paradigm to address a persistent and difficult medical challenge.
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 is also an important parameter, providing information on the level of inflammation in and around the wound. While the smart bandages combine pH and temperature sensors, flexible sensors also were developed for oxygenation — another marker of healing — that can be integrated into the bandage. Inflammation could also be tracked not just by heat, but by specific biomarkers as well.
A microprocessor reads the data from the sensors and can release a 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 3 mm thick. Components were selected to keep the bandage low-cost and disposable, except for the microprocessor, which can be re-used.
The bandages could embed other sensing components, drugs, and growth factors that treat different conditions in response to different healing markers. The smart bandages have been created and tested successfully under in-vitro conditions.