Elevating Postinjection\nStability in Silk Nanofibril\nHydrogels to Prevent Intervertebral Disc Degeneration

Injectable hydrogels offer a minimally invasive approach\nto treating\nintervertebral disc degeneration, a prevalent condition that affects\n90% of individuals and often leads to significant pain and disability.\nDespite being a critical yet often overlooked issue that could lead\nto suboptimal therapeutic outcomes, the mechanical integrity of these\ngels frequently diminishes postinjection due to the injection process\nitself. To address this challenge, our research developed a silk-nanofibril-based\nhydrogel enhanced through simple <i>in situ</i> polymerization\nof dopamine. The resulting hydrogel not only effectively preserved\nits modulus at over 1000 Pa postinjection, matching the mechanical\nproperties of the nucleus pulposus, but also significantly enhanced\nits antioxidative properties to four times that of the original silk\nnanofibril-based hydrogel. Furthermore, both cell-based and animal\nstudies substantiated that such a silk nanofibril-based hydrogel integrated\nwith polydopamine exhibited significant therapeutic efficacy in the\ninjectable treatment of intervertebral disc degeneration. Therefore,\nthis work introduced a new perspective on the design of injectable\nhydrogels that could effectively address both the mechanical and biochemical\nchallenges of degenerative disc diseases, providing a platform for\nsubsequent therapeutic interventions.