Mimetic Core-Sheath Silk Sutures with Superior-Strength for Pain Management, Anti-Infection and Wound Healing

Sutures are crucial for tissue approximation and wound healing. Besides their strength limits requirement, they often fail to effectively address complications like infection and pain. Inspired by natural silk's "core-sheath" structure, our suture features a wet-spun core of n zinc-fortified silk fibroin fibers (RSF-Zn²⁺) after drawing with over 800 MPa strength and around steel-like 30GPa modulus, forming a robust structure (TZS_n). The outer shell is a photo-crosslinked methacrylated sericin (SerMA) with Prilocaine- (PSTZS₁₂) for pain relief. PSTZS₁₂ (215 micrometers) can endure a maximum tensile force of 13.78 N which is double that of commercial 5-0 Mersilk sutures (235 micrometers). Our silk mimetic hydrogel suture PSTZS₁₂ reaches superior strength coordinating with pain-control (prilocaine), antimicrobial (Zn²⁺), and wound repair ability (silk). PET/CT studies of a rat pain model show that the sutures reduce the metabolic levels of ¹⁸F-FDG in 14 pain-related brain regions, including the cingulate cortex and somatosensory cortex, directly impacting pain management. The suture promotes fibroblast migration, angiogenesis and accelerates wound healing.