From passive closure to active therapy: Interfacial bridging Medi-MOF sutures for diabetic wound healing

A Medi-MOF suture implemented a “drainage–response–release” therapeutic strategy. • Bioinspired urushiol interfacial bridging enabled anchoring of Medi-MOF on suture. • The suture realized pH-responsive release of curcumin and Zn 2+ in diabetic wounds. • The suture showed potent antibacterial, immunomodulatory, and angiogenic activity. • The suture promoted tissue regeneration for diabetic wound healing. Surgical sutures are indispensable for wound closure, but they may promote bacterial colonization and exacerbate inflammation as they are often treated as passive materials. Impaired immune function and vascular dysfunction can severely hinder wound healing particularly in diabetic wounds. Herein, a bioinspired therapeutic silk suture system was constructed which integrated interfacial engineering with responsive drug delivery to address these limitations. A curcumin-based metal–organic framework (Medi-MOF) was immobilized onto silk sutures via an urushiol-mediated interfacial layer, forming a robust coating. Benefiting from the unique molecular structure and rapid curing properties of urushiol, MOF nanoparticles can be stably anchored through a variety of interactions, including hydrogen bonding, π–π stacking and metal coordination. The system exhibited pH-responsive release behavior in vitro , with accelerated Medi-MOF degradation and increased curcumin/Zn 2+ release under acidic conditions, while maintaining slower release under physiological conditions. Notably, immobilization onto the silk substrate further modulates release kinetics, resulting in a hierarchical mechanism that combines diffusion control with pH-responsive release. Moreover, the inherent capillary wicking property of braided silk sutures, traditionally regarded as a drawback, is transformed into a functional advantage by facilitating liquid transport and promoting contact between wound fluid and the Medi-MOF coating. This capillary wicking-assisted pH-responsive release strategy contributed to bacterial infection, modulated inflammation, and promoted tissue regeneration. Overall, this work provided a new paradigm for transforming sutures from passive closure devices into bioactive therapeutic platforms for diabetic wound management. Download: Download high-res image (178KB) Download: Download full-size image