Abstract
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.