Hydrogel Microneedle Array-Based Transdermal Dressing System for Multiplexed Assessment and Combined Therapy of Chronic Wounds

Although recent wearable chronic wound (CWO) bandage technologies have opened up exciting opportunities for personalized CWO management, they still face significant obstacles due to the reliance on the wound bed exudate for sensing and delivering therapeutics. Flat, shallow, and desiccated wounds are difficult to collect wound exudate for sensing, and some wounds continuously exude, potentially washing delivered therapeutics out of the wound bed. Herein, we developed a hydrogel-forming microneedles (HFMNs) array-based multimodal transdermal dressing system that continuously monitors the on-site physiological conditions of CWOs in interstitial fluid (ISF) and offers healing capabilities. The unique polar array design enables the integration of six replaceable HFMNs sensing electrodes to target the desired wound-specific analytes in transdermal interstitial fluid (glucose, uric acid, pH, Na+, Cl-, K+, and temperature) based on their significance in reflecting the status of the CWOs. The hydrogel is composed of a biocompatible and swellable polymer - polyvinyl alcohol, and chitosan as a crosslinking agent, while the incorporation of MXene (Ti3C2Tx) nanosheets as conductive nanofillers facilitates the formation of 3D polymer hydrogel networks via hydrogen bonding. Further coating and functionalization of poly(3,4-ethylenedioxythiophene): polystyrene sulfate (PEDOT: PSS) and graphene oxide through a laser-scribed phase separation (LSPS) process improves the electrical conductivity and in-vivo water stability of the HFMNs as a result of the larger and interconnected PEDOT-rich domains. Importantly, anti-inflammatory and antibacterial properties of the hydrogel prevent wound infection and promote skin wound healing. Through the potential correlation between wound-affected ISF and wound bed exudate, this method bridges conventional and implantable dressing systems for commercialization.