Progress in clinical trials of cell transplantation for the treatment of spinal cord injury: how many questions remain unanswered?

Abstract

Spinal cord injury can lead to severe motor, sensory and autonomic nervous dysfunctions. However, there is currently no effective treatment for spinal cord injury. Neural stem cells and progenitor cells, bone marrow mesenchymal stem cells, olfactory ensheathing cells, umbilical cord blood stem cells, adipose stem cells, hematopoietic stem cells, oligodendrocyte precursor cells, macrophages and Schwann cells have been studied as potential treatments for spinal cord injury. These treatments were mainly performed in animals. However, subtle changes in sensory function, nerve root movement and pain cannot be fully investigated with animal studies. Although these cell types have shown excellent safety and effectiveness in various animal models, sufficient evidence of efficacy for clinical translation is still lacking. Cell transplantation should be combined with tissue engineering scaffolds, local drug delivery systems, postoperative adjuvant therapy and physical rehabilitation training as part of a comprehensive treatment plan to provide the possibility for patients with SCI to return to normal life. This review summarizes and analyzes the clinical trials of cell transplantation therapy in spinal cord injury, with the aim of providing a rational foundation for the development of clinical treatments for spinal cord injury.

Pharmacological Modulation of Neurite Outgrowth in Human Neural Progenitor Cells by Inhibiting Non-muscle Myosin II

“…Using this system, we established the role of NMII in neurite generation, as well as its upstream regulation by the RhoA/ROCK1 signaling pathway. These results may provide new perspectives in the development of stem cells therapies as NMII might be considered as a novel drug target for integrating transplanted cells in neurodegenerative disorders, such as Parkinson's and Alzheimer's diseases, as well as in traumatic brain and spinal cord injuries (Ford et al, 2020;Lengel et al, 2020;Liu et al, 2020;Parmar et al, 2020;Bagheri-Mohammadi, 2021;Hu et al, 2021).…”

Hydrogen Promotes the Effectiveness of Bone Mesenchymal Stem Cell Transplantation in Rats with Spinal Cord Injury

“…Imbalanced microenvironments (inflammatory response and oxidative stress) were the most severe during this period, which led to low cell viability and insufficient secretion of the transplanted stem cells [ 16 ]. The main methods of cell transplantation for the treatment of SCI include spinal cord local injection, intrathecal transplantation (ICT), and intravenous injection [ 20 , 21 ]. Despite the different transplantation routes, the cell viability was low and could not survive for a long time.…”

Spinal cord injury: Olfactory ensheathing cell‐based therapeutic strategies

“…Sufficient evidence of OEC transplantation for SCI has been presented with the success of in vivo and in vitro experiments (Assinck et al., 2017). Nevertheless, the benefits of OEC transplantation in patients remain unclear (Hu et al., 2021). Therefore, it is necessary to optimize cell‐based therapeutic strategies to improve the efficacy of OECs in SCI.…”