Application and current challenges of neural stem cells transplantation in clinical trials of spinal cord injury

Spinal cord injury (SCI) can lead to sensory, motor, and autonomic dysfunction, and even accompanied by persistent pathological pain, seriously affecting the psychosomatic health of patients. At present, there are no effective treatment methods. In recent years, cell transplantation replacement therapy has entered people's field of vision. Functional bioactive cells are transplanted into the host to exert the characteristics of biotherapy so as to repair the injured nerve and repair the function. Neural stem cells (NSCs) are a kind of pluripotent stem cells, which have been well applied in nerve injury repair and tissue engineering regeneration. In preclinical and animal models, NSCs transplantation can well repair SCI and repair part of the function. The therapeutic functions of NSCs include differentiation into neurons, promoting axonal regeneration and myelination, neuroprotection, immunoregulation, and improving the local inflammatory microenvironment of SCI, replacing injured neurons. it is beneficial to the repair and reconstruction of neural network after SCI. NSCs have also achieved some encouraging results in clinical trials of SCI. Transplantation of NSCs into patients with SCI is a safe and feasible treatment, which can partially restore the sensory and motor function of the patients, without obvious side effects. At present, NSCs are in the primary exploration stage in clinical trials, and there are many problems and challenges in their extensive development and application in clinical trials. Therefore, we comprehensively discussed the application of NSCs in clinical trials of SCI and the existing problems and challenges, so as to provide useful information for the application of NSCs in SCI in the future.