Oxidative stress caused by the overexpression of reactive oxygen species (ROS) plays an important role in the pathogenesis of traumatic brain injury (TBI). Accumulation of ROS can lead to cell death, neurodegeneration, and neurological deficit. Therefore, the design and application of functional materials with ROS scavenging ability is of great significance for neural repair. Herein, an injectable and antioxidant hydrogel was developed for TBI treatment based on the Schiff base reaction of gallic acid-conjugated gelatin (GGA) and oxidized dextran (Odex). The resulting GGA/Odex hydrogel could effectively scavenge DPPH and ABTS radicals, as well as protect cells from the oxidative damage in vitro. Moreover, GGA/Odex hydrogel possessed well biocompatible features. In a moderate TBI mouse model, in situ implantation of GGA₆Odex hydrogel efficiently facilitated neurogenesis and promoted the motor, learning and memory abilities. Also, this composite hydrogel suppressed oxidative stress and inflammation via the activation of Nrf2/HO-1 pathway and the regulating of inflammatory factors secretion and macrophage/microglia polarization. Therefore, this injectable and ROS-scavenging GGA₆Odex hydrogel is a promising biomaterial for tissue regenerative medicine, including TBI and other tissue repair relevant to raised ROS circumstance.

活性氧（ROS）过度表达引起的氧化应激在创伤性脑损伤（TBI）的发病机制中发挥着重要作用。ROS 的积累可导致细胞死亡、神经变性和神经功能缺损。因此，具有ROS清除能力的功能材料的设计和应用对于神经修复具有重要意义。在此，基于没食子酸共轭明胶（GGA）和氧化葡聚糖（Odex）的席夫碱反应，开发了一种用于 TBI 治疗的可注射抗氧化水凝胶。所得的GGA/Odex水凝胶可以有效清除DPPH和ABTS自由基，并在体外保护细胞免受氧化损伤。此外，GGA/Odex水凝胶具有良好的生物相容性。在中度TBI 小鼠模型中，原位植入 GGA ₆ Odex 水凝胶可有效促进神经发生并促进运动、学习和记忆能力。此外，这种复合水凝胶通过激活Nrf2/HO-1通路以及调节炎症因子分泌和巨噬细胞/小胶质细胞极化来抑制氧化应激和炎症。因此，这种可注射和 ROS 清除的 GGA ₆ Odex 水凝胶是一种有前途的组织再生医学生物材料，包括 TBI 和与 ROS 环境升高相关的其他组织修复。