Emerging Regenerative Medicine for Spinal Cord Injury: Spinal Cord Organoids-on-a-Chip.

Spinal cord injury (SCI) is among the most devastating neurological conditions worldwide, imposing substantial clinical, psychological, and socioeconomic burdens on affected individuals and healthcare services. However, a translational gap persists between preclinical findings and therapeutically relevant human applications, partly involving the limitations of conventional two-dimensional culture systems, which inadequately reproduce the complex three-dimensional structure of the spinal cord; and partly due to the fact that animal models differ from humans phylogenetically and physiologically. Recent advances in three-dimensional spinal cord organoids and organoid-on-a-chip microfluidic platforms have provided new opportunities to model human spinal cord biology with greater fidelity. This review discusses the clinical and socioeconomic burden of SCI, identifies the limitations of existing experimental platforms, and explains how microfluidics and scaffold technologies may converge to accelerate the development of regenerative therapies. It also summarizes methodological innovations, recent advances, unresolved challenges, and future prospects in this rapidly evolving field.