A MnO2 Nanoparticle-Dotted Hydrogel Promotes Spinal Cord Repair via Regulating Reactive Oxygen Species Microenvironment and Synergizing with Mesenchymal Stem Cells

Spinal cord injury (SCI) is one of the most debilitating injuries and transplantation of stem cells in a scaffold is a promising strategy for the treatment. However, the stem cell treatment of SCI has been severely impaired by the increased generation of reactive oxygen species in the lesion microenvironment, which can lead to a high level of stem cell death and dysfunction. Herein, a MnO2 nanoparticle (NP)-dotted hydrogel is prepared through dispersion of MnO2 NPs in a PPFLMLLKGSTR peptide modified hyaluronic acid hydrogel. The peptide modified hydrogel enables the adhesive growth of mesenchymal stem cells (MSCs) and nerve tissue bridging. The MnO2 NPs alleviate the oxidative environment, thereby effectively improving the viability of MSCs. Transplantation of MSCs in the multifunctional gel generates a significant motor function restoration on a long-span rat spinal cord transection model and induces an in vivo integration as well as neural differentiation of the implanted MSCs, leading to a highly effic...