Neural Organoids and Organoid Extracellular Vesicles for Spinal Cord Injury Repair

Spinal cord injury (SCI) causes long-term disability in part because secondary injury progressively reshapes the lesion microenvironment and restricts axonal regeneration, circuit re-establishment, and white matter repair. Neural organoids are emerging from human pluripotent stem cell-derived disease models into implantable regenerative constructs that may provide structured cellular niches, support host-graft integration, and contribute to remyelination. However, their translation remains constrained by batch variability, limited vascularization, immune-related risk, and long-term safety concerns. In parallel, organoid-derived extracellular vesicles (OEVs) represent a cell-free modality linked to the organoid platform and are more amenable to controlled dosing and repeated administration. However, direct evidence supporting the therapeutic use of neural OEVs in SCI remains limited. OEVs should not be viewed as inherently superior alternatives to conventional extracellular vesicles (EVs); rather, their potential distinctiveness depends on experimentally verifiable links to source-organoid identity, developmental stage, multicellular context, and cargo-function logic. In SCI repair, current evidence should be stratified into direct evidence from neural OEV studies, supportive evidence from SCI-relevant conventional EV systems and related organoid/OEV studies, and testable translational hypotheses. This Review defines neural organoids and neural OEVs as source-linked but mechanistically non-equivalent repair modules, and proposes a mechanism-linked, stage-aware, and quality-oriented framework to guide OEV characterization, benchmarking, and translational evaluation for SCI repair.