Cell Transplantation and Neuroengineering Approach for Spinal Cord Injury Treatment: A Summary of Current Laboratory Findings and Review of Literature

Abstract

Spinal cord injury (SCI) can cause severe traumatic injury to the central nervous system (CNS). Current therapeutic effects achieved for SCI in clinical medicine show that there is still a long way to go to reach the desired goal of full or significant functional recovery. In basic medical research, however, cell transplantation, gene therapy, application of cytokines, and biomaterial scaffolds have been widely used and investigated as treatments for SCI. All of these strategies when used separately would help rebuild, to some extent, the neural circuits in the lesion area of the spinal cord. In light of this, it is generally accepted that a combined treatment may be a more effective strategy. This review focuses primarily on our recent series of work on transplantation of Schwann cells and adult stem cells, and transplantation of stem cell-derived neural network scaffolds with functional synapses. Arising from this, an artificial neural network (an exogenous neuronal relay) has been designed and fabricated by us-a biomaterial scaffold implanted with Schwann cells modified by the neurotrophin-3 (NT-3) gene and adult stem cells modified with the TrkC (receptor of NT-3) gene. More importantly, experimental evidence suggests that the novel artificial network can integrate with the host tissue and serve as an exogenous neuronal relay for signal transfer and functional improvement of SCI.

Increased vascularization promotes functional recovery in the transected spinal cord rats by implanted vascular endothelial growth factor‐targeting collagen scaffold

“…Currently, nerve repair and functional recovery after SCI are still plagued by problems in clinical medicine. In recent years, scaffolds and cytokines were used for neural repair and functional recovery …”

The cell repair research of spinal cord injury: a review of cell transplantation to treat spinal cord injury

“…Although MGE progenitor cells and interneuron-like cells have been produced from mouse and human stem cells, little is known about the way to reduce tumorigenesis, the time it takes to function after transplantation, or the long-term effects after transplantation [14]. Experiment on larger animal models is also rare.…”

“…In order to improve the survival rate of transplanted cells and maximize their effect, the application of gene therapy, bioengineered scaffolds and drugs, and multiple cell transplantation are increasingly gaining the attention and recognition of researchers. The key to elevating these methods is to establish a good interaction environment between cells, scaffolds and bioactive molecules to promote the repair of damaged tissues more effectively [14].…”

“…The basic strategy of gene therapy for spinal cord repair is to transcribe specific genes to the site of injury, creating a good microenvironment [14]. Transgenic stem cells can not only improve the ability of cells to differentiate, but also express a large number of specific neurotrophic factors and reconstruct the spinal nerve circuit [50].…”

“…Different transplantation methods have their own advantages and disadvantages. The most widely used method is the local transplantation, which is the most effective but also the most invasive, while the vascular transplantation is opposite [11,12,14]. It is generally believed that the optimal time for cell therapy is within 2~4 weeks after trauma.…”