Polyphenol-Mediated\nAdhesive and Anti-Inflammatory\nDouble-Network Hydrogels for Repairing Postoperative Intervertebral\nDisc Defects

Hydrogels\nhave garnered tremendous attention for their applications\nin the repair of intervertebral disk (IVD) degeneration and postoperative\nIVD defects. However, it is still challenging to develop a hydrogel\nfulfilling the requirements for high mechanical properties, adhesive\ncapability, biocompatibility, antibacterial properties, and anti-inflammatory\nperformance. Herein, we report a multifunctional double-network (DN)\nhydrogel composed of physically cross-linked carboxymethyl chitosan\n(CMCS) and tannic acid (TA) networks as well as chemically cross-linked\nacrylamide (AM) networks, which integrates the properties of high\nstrength, adhesion, biocompatibility, antimicrobial activity, and\nanti-inflammation for the repair of postoperative IVD defects. The\ntreatment with CMCS/TA/PAM DN hydrogels can significantly decrease\nthe levels of inflammatory cytokines and degeneration-related factors\nand upregulated collagen type II alpha 1. In addition, the hydrogels\ncan effectively seal the annulus fibrosus defect, prevent nucleus\npulposus degeneration, retain IVD height, and restore the biomechanical\nproperties of the disc to some extent. This polyphenol-mediated DN\nhydrogel is promising for sealing IVD defects and preventing herniation\nafter lumbar discectomy.