Chronic wounds such as diabetic feet undergo a lifetime risk of developing into incurable ulcers. Current treatments for chronic wounds remain unsatisfactory due to the lack of ideal wound dressings that integrate facile dressing change, long‐acting treatment, and high therapeutic efficacy into one system. Herein, a synergistically detachable microneedle (MN) dressing with a dual‐layer structure is presented to enable programmed treatment via one‐time dressing application. Such a dual‐layer dressing MN system (DDMNS) is composed of chitosan (CS) hydrogel dressing (CSHD) on top of a detachable MN patch with a CS tip and a polyvinyl pyrrolidone (PVP) backing substrate incorporated with magnesium (Mg). The synergistic detachment is achieved with the backing Mg/PVP substrate dissolving within minutes due to the local moist environment of the CSHD enhancing the reaction between Mg and inflammation microenvironment. The combined treatment of Mg and panax notoginseng saponins (PNS) loaded in DDMNS achieves antibacterial, neovascularization, and activating a benign immune response so that the three overlapping periods of the inflammation, tissue proliferation, and tissue remodeling of wound healing reach a dynamic balance. This advanced DDMNS provides a facile approach for the programmed treatment of chronic wound management indicating potential value in wound healing and other related biomedical fields.

Chronic Wound Healing Article number 2102180 by Xufeng Niu, Yubo Fan, and co‐workers, demonstrates a synergistically detachable microneedle dressing to enable programmed treatment of chronic wounds: a) The needle detaches rapidly under the synergistic acceleration of magnesium and chitosan hydrogel in the separation layer. b) Multi‐stage release of multiple drugs. c) Clinical efficacy of microneedle dressing: antibacterial, promoting angiogenesis, anti‐inflammatory d) Regulation of macrophages by microneedle dressing.

On-demand drug delivery systems (DDSs) have tremendous promise for clinical in vivo personalized drug delivery. However, the current DDSs are monofunctional and unable to meet the individualized needs of patients. Herein, a biodegradable multifunctional active-controlled drug delivery system (ADDS) is reported. The device can be implanted in various tissues with valves controlled by the deactivation of magnesium (Mg) for rapid drug release from drug reservoirs and long-term drug delivery with the biodegradation of the ADDS. Multiple chambers are constructed by designing a structure with tandem Mg valves and aligning them in the z-axis direction, allowing the system to deliver drugs in a pulsatile or sequential manner. The biodegradability of the entire system minimizes the potential side effects of the ADDS. The application of the device for drug delivery in rats confirmed its ability to perform pulsatile delivery in vivo. The excellent biocompatibility and dual timeline drug delivery capability of this system are demonstrated with cellular and in vitro vascular bioreactors. This multifunctional ADDS will play an important role in precise drug delivery in the treatment of chronic diseases and diseases with complications.

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