Lab-on-a-Fiber Wearable Multi-Sensor for Monitoring Wound Healing

Chronic wounds are regarded as a silent epidemic, affecting 1-2% of the population and representing 2-4% of healthcare expenses. The current methods used to assess the wound healing process are based on the visual evaluation of physical parameters. This work aims to design a wearable non-invasive device capable of evaluating three parameters simultaneously: the pH and the levels of glucose and matrix metalloproteinase (MMP) present in the wound exudate. The device is composed of three independent polymer optical fibers functionalized with fluorescent-based sensing chemistries specific to the targeted analytes. Each fiber is characterized in terms of detection sensitivity and selectivity confirming their suitability for monitoring the targeted parameters in ranges relevant to the wound environment. The selectivity and robustness of the multi-sensing device are confirmed with analyses using complex solutions with different pH levels (5, 6, and 7), different concentrations of glucose (1.25, 2.5, and 5 mm), and MMP (1.25, 2.5, and 5 µg mL^-1 ). Given the simple set-up, the affordability of the materials used and the possibility of detecting additional parameters relevant to wound healing, such multi-sensing fiber-based devices could pave the way for novel non-invasive wearable tools enabling the assessment of wound healing from the molecular perspective.