Hydrogel Microneedle Array-Based Transdermal Dressing System for Multiplexed Assessment and Intelligent Therapy of...

Topical chronic wound dressings offer personalized management but have limited efficacy in sensing and delivering therapeutics due to their reliance on the wound surface. Herein, a theranostic hydrogel-forming microneedles (HFMNs) dressing system is developed that penetrates the epidermis to continuously sample dermal wound interstitial fluid (ISF), providing high-fidelity diagnostics and active therapy. The dressing is fabricated from a polyvinyl alcohol/chitosan hydrogel incorporating MXene for intrinsic antibacterial and pro-healing properties. Central to the platform's design is a laser-scribed phase separation process that converts a poly(3,4-ethylenedioxythiophene): polystyrene sulfate/graphene oxide coating into highly conductive (384 S/m) and water-stable electrodes directly on the HFMNs. This enables a multiplexed, replaceable array for continuously monitoring seven key wound biomarkers: glucose, uric acid, Na⁺, K⁺, Cl^-, pH, and temperature. In vitro studies confirmed the dressing's cytocompatibility and antimicrobial efficacy against E. coli and S. aureus, while in vivo rat models showed accelerated wound closure. Critically, the HFMN system captured the biochemical dynamics of wound infection and healing from wound ISF with significantly greater fidelity and more distinct responses compared to conventional surface sensors sampling exudate. This work validates a robust platform that directly links deep-tissue biomarkers to wound state, paving the way for personalized, proactive chronic wound management.