ROS-Responsive Wedelolactone Hydrogel Promotes Intervertebral Disc Repair by Disrupting the NF-κB-LCN2 Inflammatory Feedback Loop

Intervertebral disc degeneration (IVDD) is driven by persistent inflammation-oxidative stress that disrupts annulus fibrosus (AF) homeostasis. Guided by network pharmacology and docking, we prioritized the NF-κB-LCN2 axis as a druggable target of wedelolactone (WDL). To achieve targeted modulation, we engineered a dual-network ROS-responsive hydrogel (WPG) in which a phenylboronic-ester/PVA redox-cleavable network interpenetrates a covalently crosslinked GelMA-elastin matrix, enabling mechanically robust yet stimulus-triggered WDL release. WDL suppressed NF-κB activation and downregulated LCN2 in both macrophages and AF cells. Conditioned-medium co-culture demonstrated that WDL disrupts macrophage-derived LCN2-mediated paracrine amplification, breaking the self-sustaining inflammatory loop. Bulk RNA-seq across both cell types revealed coordinated downregulation of NF-κB - driven chemokine cascades and restoration of adhesion and ECM gene programs following WPG treatment. In a rat AF-defect model, intradiscal WPG administration preserved disc height and T₂-weighted MRI signal, reduced MMP13 while increasing Collagen I and Aggrecan expression, suppressed nuclear P-p65 and LCN2, and improved segment biomechanics-without eliciting adverse hematological or organ responses. Collectively, these findings establish that aligning molecular targeting (NF-κB-LCN2 modulation) with the pathophysiological context via ROS-gated delivery provides a synergistic strategy for AF repair and attenuation of IVDD progression.