Intelligent microneedle patch with prolonged local release of hydrogen and magnesium ions for diabetic wound healing

Diabetes mellitus, an epidemic with a rapidly increasing number of patients, always leads to delayed wound healing associated with consistent pro-inflammatory M1 polarization, decreased angiogenesis and increased reactive oxygen species (ROS) in the microenvironment. Herein, a poly (lactic-co-glycolic acid) (PLGA)-based microneedle patch loaded with magnesium hydride (MgH(2)) (MN-MgH(2)) is manufactured for defeating diabetic wounds. The application of microneedle patch contributes to the transdermal delivery and the prolonged release of MgH(2) that can generate hydrogen (H(2)) and magnesium ions (Mg(2+)) after reaction with body fluids. The released H(2) reduces the production of ROS, transforming the pathological microenvironment induced by diabetes mellitus. Meanwhile, the released Mg(2+) promotes the polarization of pro-healing M2 macrophages. Consequently, cell proliferation and migration are improved, and angiogenesis and tissue regeneration are enhanced. Such intelligent microneedle patch provides a novel way for accelerating wound healing through steadily preserving and releasing of H(2) and Mg(2+) locally and sustainably.