Synergistic delivery of ginseng exosomes and biomimetic melanosomes via temporally controlled hydrogel microneedles restrain the pathologic triad of vitiligo

Vitiligo pathogenesis involves progressive melanocyte loss and keratinocyte dysfunction, which are driven primarily by oxidative stress resulting from excessive ROS accumulation. We engineered a temporally controlled hydrogel microneedle system that integrates ginseng-derived exosomes (G-Exos) with biomimetic polydopamine nanoparticles (PDA@PEGs) to concurrently target the pathogenic triad of vitiligo, including oxidative stress, inflammation, and melanocyte deficiency. This system employs methacrylated hyaluronic acid (HAMA) hydrogel microneedles for rapid PDA@PEG release while utilizing glyceryl monostearate micelles to achieve matrix metalloproteinase-9 (MMP-9)-responsive G-Exo release at inflammatory foci, enabling intelligent spatiotemporal control. Functionally, G-Exos help restore redox homeostasis and suppress inflammation through bioactive constituents, thereby protecting melanocytes and enhancing keratinocyte proliferation. Moreover, PDA@PEG promotes repigmentation through the dual mechanisms of exogenous melanin deposition and endogenous melanogenesis stimulation. In murine models, this strategy achieves significant repigmentation within 3 weeks by activating follicular stem cells, upregulating melanogenic markers (Tyr/Mc1r), increasing antioxidant defense (ApoE), and suppressing inflammatory signaling (IL-17). This natural-biomimetic hybrid design leverages biocompatible materials to co-target multiple pathological axes, offering a novel self-adaptive approach for microenvironmental rehabilitation in vitiligo.