Advances and prospects of cell therapy for spinal cord injury patients

Spinal cord injury (SCI) is catastrophic damage for patients, their family, and society. Researchers and clinicians have been trying to find neurorestorative methods to recover their injured functions and structures. Cell therapy is one of the effective therapeutic strategies for SCI. And it can partially restore their neurological functions, which are once thought as permanent neurological deficits. Currently, cells being used therapeutically in clinic include olfactory ensheathing cells (OECs), mononuclear cells (MNCs), mesenchymal stromal cells (MSCs), Schwann cells, and hematopoietic stem cells, cell products differentiated from embryonic stem cells, mesenchymal stem cells, induced pluripotent stem cells, and neural stem cells as well as other kinds of cells. Real world data from these cell therapies showed some benefits in some patients with SCI. Due to being affected by many factors, the therapeutic results of some kinds of cells are contradictory and it is hard to compare effects among different types of cells. According to the data of cell therapies, OEC, MNC and MSC transplantation are applied for patients in majority percentage of cases, and OEC transplantation had a higher percentage of benefits. In next step, under the unified standard of cell preparation and quality control as well as the guidelines of clinical cell application, each kind of cells including OECs should be studied using prospective, multicenter, double-blind or observing-blind, placebo-control, randomized studies for SCI patients with different level of injury and chronicity.