Spinal cord injuries (SCIs) can lead to significant neurological deficits and lifelong disability, with far-reaching physical, psychological, and economic consequences for affected individuals and their families. Current treatments for SCIs are limited in their ability to restore function, and there is a pressing need for innovative therapeutic approaches. Stem cell therapy has emerged as a promising strategy to promote the regeneration and repair of damaged neural tissue following SCIs. This review article comprehensively discusses the potential of different stem cell types, such as embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), mesenchymal stem cells (MSCs), and neural stem/progenitor cells (NSPCs), in SCI treatment. We provide an in-depth analysis of the unique advantages and challenges associated with each stem cell type, as well as the latest advancements in the field. Furthermore, we address the critical challenges faced in stem cell therapy for SCIs, including safety concerns, ethical considerations, standardization of protocols, optimization of transplantation parameters, and the development of effective outcome measures. We also discuss the integration of novel technologies such as gene editing, biomaterials, and tissue engineering to enhance the therapeutic potential of stem cells. The article concludes by emphasizing the importance of collaborative efforts among various stakeholders in the scientific community, including researchers, clinicians, bioengineers, industry partners, and patients, to overcome these challenges and realize the full potential of stem cell therapy for SCI patients. By fostering such collaborations and advancing our understanding of stem cell biology and regenerative medicine, we can pave the way for the development of groundbreaking therapies that improve the lives of those affected by SCIs.

Spinal cord injury (SCI) represents a significant medical challenge, often resulting in permanent disability and severely impacting the quality of life for affected individuals. Traditional treatment options remain limited, underscoring the need for novel therapeutic approaches. In recent years, multipotent mesenchymal stem cells (MSCs) have emerged as a promising candidate for SCI treatment due to their multifaceted regenerative capabilities. This comprehensive review synthesizes the current understanding of the molecular mechanisms underlying MSC-mediated tissue repair in SCI. Key mechanisms discussed include neuroprotection through the secretion of growth factors and cytokines, promotion of neuronal regeneration via MSC differentiation into neural cell types, angiogenesis through the release of pro-angiogenic factors, immunomodulation by modulating immune cell activity, axonal regeneration driven by neurotrophic factors, and glial scar reduction via modulation of extracellular matrix components. Additionally, the review examines the various clinical applications of MSCs in SCI treatment, such as direct cell transplantation into the injured spinal cord, tissue engineering using biomaterial scaffolds that support MSC survival and integration, and innovative cell-based therapies like MSC-derived exosomes, which possess regenerative and neuroprotective properties. As the field progresses, it is crucial to address the challenges associated with MSC-based therapies, including determining optimal sources, intervention timing, and delivery methods, as well as developing standardized protocols for MSC isolation, expansion, and characterization. Overcoming these challenges will facilitate the translation of preclinical findings into clinical practice, providing new hope and improved treatment options for individuals living with the devastating consequences of SCI.

The human nervous system exhibits limited regenerative capabilities following damage to the central nervous system (CNS), leading to a scarcity of effective treatments for nerve function recovery. In contrast, zebrafish demonstrate remarkable regenerative abilities, making them an ideal model for studying the modulation of inflammatory processes after injury. Such research holds significant translational potential to enhance our understanding of recovery from damage and disease. Macrophages play a crucial role in tissue repair and regeneration, with their subpopulations indirectly promoting axonal regeneration through developmental signals. The AP-1 signaling pathway, mediated by TNF/Tnfrsf1a, can elevate HDAC1 expression and facilitate regeneration. Furthermore, following spinal cord injury (SCI), pMN progenitors have been observed to switch between oligodendrocyte and motor neuron fates, with macrophage-secreted TNF-α potentially regulating the differentiation of ependymal–radial glia progenitors and oligodendrocytes. Radial glial cells (RGs) are also essential for CNS regeneration in zebrafish, as they perform neurogenesis and gliogenesis, with specific RG subpopulations potentially existing for the generation of neurons and oligodendrocytes. This review article underscores the critical role of macrophages and their subpopulations in tissue repair and regeneration, focusing on their secretion of TNF-α, which promotes axonal regeneration in zebrafish. We also offer insights into the molecular mechanisms underlying TNF-α’s ability to facilitate axonal regeneration and explore the potential of pMN progenitor cells and RGs following SCI in zebrafish. The review concludes with a discussion of various unresolved questions in the field, and ideas are suggested for future research. Studying innate immune cell interactions with neuroglia following injury may lead to the development of novel strategies for treating the inflammatory processes associated with regenerative medicine, which are commonly observed in injury and disease.

Neuronal regeneration after injury: a new perspective on gene therapy

Spinal cord injury (SCI) is a devastating event that results in a wide range of physical impairments and disabilities. Despite the advances in our understanding of the biological response to injured tissue, no effective treatments are available for SCIs at present. Some studies have addressed this issue by exploring the potential of cell transplantation therapy. However, because of the abnormal microenvironment in injured tissue, the survival rate of transplanted cells is often low, thus limiting the efficacy of such treatments. Many studies have attempted to overcome these obstacles using a variety of cell types and animal models. Recent studies have shown the utility of zebrafish as a model of neural regeneration following SCIs, including the proliferation and migration of various cell types and the involvement of various progenitor cells. In this review, we discuss some of the current challenges in SCI research, including the accurate identification of cell types involved in neural regeneration, the adverse microenvironment created by SCIs, attenuated immune responses that inhibit nerve regeneration, and glial scar formation that prevents axonal regeneration. More in-depth studies are needed to fully understand the neural regeneration mechanisms, proteins, and signaling pathways involved in the complex interactions between the SCI microenvironment and transplanted cells in non-mammals, particularly in the zebrafish model, which could, in turn, lead to new therapeutic approaches to treat SCIs in humans and other mammals.

Spinal cord injury (SCI) is a life-altering condition that leads to severe neurological deficits and significantly impacts patients’ quality of life. Despite advancements in medical care, current treatment options remain largely palliative, with limited ability to promote meaningful functional recovery. Induced pluripotent stem cells (iPSCs) have emerged as a promising avenue for regenerative medicine, offering patient-specific, cell-based therapeutic potential for SCI repair. This review provides a comprehensive overview of recent advancements in iPSC-based approaches for SCI, detailing the strategies used to generate neural cell types, including neural progenitor cells, oligodendrocytes, astrocytes, and microglia, and their roles in promoting neuroprotection and regeneration. Additionally, we examine key preclinical and clinical studies, highlighting functional recovery assessments and discussing both standardized and debated evaluation metrics. Furthermore, we address critical challenges related to safety, tumorigenicity, immune response, survival, integration, and overcoming the inhibitory microenvironment of the injured spinal cord. We also explore emerging approaches in biomaterial scaffolds, gene editing, and rehabilitation strategies that may enhance the clinical applicability of iPSC-based therapies. By addressing these challenges and refining translational strategies, iPSC-based interventions hold significant potential to revolutionize SCI treatment and improve outcomes for affected individuals.