ROS-Scavenging Hydrogels Synergize with Neural Stem Cells to Enhance Spinal Cord Injury Repair via Regulating Microenvironment and Facilitating Nerve Regeneration.

Although stem cell-based therapy is recognized as a promising therapeutic strategy for spinal cord injury (SCI), its efficacy is greatly limited by local reactive oxygen species (ROS)-abundant and hyper-inflammatory microenvironments. It is still a challenge to develope bioactive scaffolds with outstanding antioxidant capacity for neural stem cells (NSCs) transplantation. In this study, albumin biomimetic cerium oxide nanoparticles (CeO 2 @BSA nanoparticles, CeNPs) are prepared in a simple and efficient manner and dispersed in gelatin methacryloyl (GelMA) to obtain the ROS-scavenging hydrogel (CeNP-Gel). CeNP-Gel synergistically promotes neurogenesis via alleviating oxidative stress microenvironments and improving the viability of encapsulated NSCs. More interestingly, in the presence of CeNP-Gel, microglial polarization to anti-inflammatory M2 subtype are obviously facilitated, which is further verified to be associated with tphosphoinositide 3-kinase (PI3K) / protein kinase B (AKT) pathway activation. Additionally, the injectable ROS-scavenging hydrogel is confirmed to induce the integration and neural differentiation of transplanted NSCs. Compared with the blank-Gel group, the survival rate of NSCs in CeNP-Gel group is about 3.5 times higher, and the neural differentiation efficiency is about 2.1 times higher. Therefore, the NSCs-laden ROS-scavenging hydrogel represents a comprehensive strategy with great application prospect for the treatment of SCI through comprehensively modulating the adverse microenvironment. This article is protected by copyright. All rights reserved.