Selenium-doped carbon quantum dots efficiently ameliorate secondary spinal cord injury via scavenging reactive oxygen species

Abstract

Background: The excess production of reactive oxygen species (ROS) after traumatic spinal cord injury (TSCI) has been identified as a leading cause of secondary injury, which can significantly exacerbate acute damage in the injured spinal cord. Thus, scavenging of ROS has emerged as an effective route to ameliorate secondary spinal cord injury. Purpose: Selenium-doped carbon quantum dots (Se-CQDs) with the ability to scavenge reactive oxygen species were prepared and used for efficiently ameliorating secondary injury in TSCI. Methods: Water-soluble Se-CQDs were easily synthesized via hydrothermal treatment of L-selenocystine. The chemical structure, size, and morphology of the Se-CQDs were characterized in detail. The biocompatibility and protective effects of the Se-CQDs against H2O2-induced oxidative damage were investigated in vitro. Moreover, the behavioral test, bladder function, histological observation, Western blot were used to investigate the neuroprotective effect of Se-CQDs in a rat model of contusion TSCI. Results: The obtained Se-CQDs exhibited good biocompatibility and remarkable protective effect against H2O2-induced oxidative damage in astrocytes and PC12 cells. Moreover, Se-CQDs displayed marked anti-inflammatory and anti-apoptotic activities, which thereby reduced the formation of glial scars and increased the survival of neurons with unscathed myelin sheaths in vivo. As a result, Se-CQDs were capable of largely improving locomotor function of rats with TSCI. Conclusion: This study suggests that Se-CQDs can be used as a promising therapeutic platform for ameliorating secondary injury in TSCI.