From three‐dimensional culture to translational modeling: Human spinal cord organoids as an emerging precision platform for neurotrauma research

Spinal cord injury (SCI) remains a debilitating neurological disorder for which no curative therapy currently exists, largely because conventional animal models and two‑dimensional cultures incompletely replicate the cellular complexity and pathophysiological dynamics of the human spinal cord. Human pluripotent stem cell (hPSC)‑derived spinal cord organoids (SCOs) provide a three‑dimensional platform that recapitulates essential features of regional patterning, cell‑type diversity, and nascent neural circuitry. This review systematically synthesises current strategies for generating these organoids through morphogen‑guided differentiation, their composition encompassing motor neurons, interneurons, astrocytes, and oligodendrocyte lineages, and the progressive incorporation of microglial and vascular elements to model neuroinflammation and barrier integrity. We critically appraise functional assessment techniques, including calcium imaging and multielectrode array recordings, alongside bioengineering advances such as microfluidic devices and bioprinting that improve structural organisation and experimental reproducibility. Despite notable progress, major constraints persist, including cellular immaturity, inadequate representation of chronic injury and ageing phenotypes, incomplete glial and vascular integration, and the absence of systemic immune and pharmacokinetic interactions. We argue that SCOs are presently best suited for mechanistic dissection, pharmacological screening, and patient‑stratified modelling, whereas therapeutic implantation remains at a preclinical stage. Translational impact will ultimately depend on rigorous standardisation, benchmarking against human reference atlases, regulatory qualification, and complementary validation using animal models and clinical endpoints.