Stem cells for spinal cord injuries bearing translational potential

Abstract

Spinal cord injury (SCI) is a highly debilitating neurological disease, which still lacks effective treatment strategies, causing significant financial burden and distress to the affected families. Nevertheless, nanotechnology and regenerative medicine strategies holding promise for the development of novel therapies that would reach from bench to bedside to serve the SCI patients. There has already been significant progress in the field of cell-based therapies, with the clinical application for SCI, currently in phase II of the clinical trial. Stem cells (e.g., induced pluripotent stem cells, fetal stem cells, human embryonic stem cells, and olfactory ensheathing cells) are certainly not to be considered the panacea for neural repair but, especially when combined with rehabilitation or other combinatorial approaches using the help of nanotechnology, they seem to be the source of some of the most promising and clinical translatable cell-based therapies that could help solving impactful problems on neural repair.

Keywords: neuroregeneration; plasticity; repair; spinal cord injury; stem cells.

Figure 1

Schematic illustration of the various adult and fetal sources for stem cells. BM-MSC: Bone marrow-derived mesenchymal stem cells; MSC: mesenchymal stem cells; UC-MSC: umbilical cord-derived mesenchymal stem cells; OEC: olfactory ensheathing cells; iPSC: induced pluripotent stem cells; hESC: human embryonic stem cells.

Figure 2

The paralysed man who can ride a bike. (A) Schematic illustration of the OECs transplantation technique and the rational behind it. After the removal of the olfactory bulb or biopsies from the olfactory mucosa, the SCI injury site is surgically exposed and the OECs are injected, after having been isolated, cultured, expanded and characterized, based on the hypothesis that the OECs transplantation will help the nerve tissue to regenerate across the spinal cord to repair the damage and lead to the patient's functional improvement. (B) This 38-year-old man is believed to be the first person in the world to recover from complete severing of the spinal nerves. He can now walk using a frame, ride an adapted tricycle and live an independent life thanks to the pioneering OECs transplantation, which was combined with a physiotherapy plan. The OEC transplantation technique was developed by the team of Prof. Raisman from the University College of London and the surgery was performed by a Polish team led by Dr. Tabakow from Wroclaw Medical University (BBC News, 2016). OECs: Olfactory ensheathing cells.