A closed-loop smart dressing based on microneedle and electrochemical micropump for early diagnosis and in-time therapy of chronic wound

Early diagnosis combined with in-time treatment is a promising strategy for chronic wound care, preventing wound deterioration and promoting healing. Different smart dressings have recently emerged to enable real-time wound status monitoring and offer active intervention. However, the drawbacks of existing smart dressings, including limited drug loading capacity and poor drug penetration into the deeper wound dermal and subcutaneous tissues, are yet to be addressed, resulting in unsatisfactory therapeutic effectiveness. In this study, a Microneedle-embedded closed-loop smart Dressing (MelD) is developed to simultaneously achieve chronic wound early diagnosis and in-time therapy. The simple impedance sensing electrodes are utilized to monitor wound impedance for chronic wound early diagnosis. Based on the sensing data, the drug delivery micropump in MelD is automatically activated for in-time therapy. By integrating micropump electrodes with a drug reservoir coupled-microneedle array, a practice solution for delivering enough drug fluid into deeper wound dermal/ subcutaneous tissues is developed. Compared to untreated diabetic mice, MelD, delivering sufficient growth factor to the wound and promoting drug entry into deep tissue layers, induces faster wound healing in treated mice. Meanwhile, MelD facilitates tissue formation and nascent collagen deposition. The enhanced drug storage dosage, improved drug penetration and closed-loop operation of Meld enable the first successful attempt of ensuring sufficient and efficient drug delivery by miniaturized all-in-one smart dressing, expanding the usage of closed-loop chronic wound care from laboratorial demonstration on limited kinds of superficial wounds to a wider range of wound types.