A fully printed stretchable microneedle bioelectronic patch for full-cycle intelligent wound management

Intelligent wound dressings offer new potential for the precision treatment of chronic non-healing wounds. However, further improvements in wound sensing accuracy and therapeutic efficiency remain challenging. Here, we present a battery-free, stretchable intelligent microneedle patch (iSMNP) that penetrates the skin barrier to achieve accurate impedance-guided closed-loop drug release and electrical stimulation for full-cycle wound management. A multi-material aerosol jet 3D printing strategy with microscale construction capability is developed to fabricate the fully printed, multilayer microneedle patch featuring high structural precision and serpentine stretchable interconnects. Benefiting from reliable stratum corneum penetration and high conductivity, the iSMNP achieves a 4.2-fold reduction in contact impedance and an 8-fold enhancement in charge injection for electrical stimulation compared with commercial gel electrodes. Closed-loop drug release is realized through an electrostatic interlocking mechanism, while the microneedle structure increases drug delivery depth by approximately 61%. Both in vitro and animal experiments demonstrate that the iSMNP effectively suppresses bacterial infection, promotes vascular normalization, and enhances tissue remodeling. This scalable microneedle-based bioelectronic platform establishes a powerful and efficient strategy for closed-loop precision therapy of chronic non-healing wounds.