Generation of engineered human spinal cord organoid in channel-patterned collagen and transplantation for spinal cord regeneration.

The construction of artificially manipulable tissue-engineered human spinal cord organoids (HSCO) in vitro is crucial for recapitulating spinal cord development and facilitating the transplantation repair of complete spinal cord injury (SCI). Here, we develop a millimeter-scale macroscopic complex scaffold assembled by Matrigel-filled channel-patterned type II collagen (CPCol II-M), in which a spheroid derived from human motor neural progenitors extends within the channel to generate the human spinal cord organoids in CPCol II-M (HSCO-CPCol II-M). The CPCol II-M scaffold, with enhanced mechanical properties, mimics the anisotropic architecture of the spinal cord and improves cell survival after long-term cultivation. Notably, the HSCO-CPCol II-M exhibits spinal cord differentiation and expresses spinal cord-associated mature neurons. When transplanted into nude mice model with completely transected SCI, HSCO-CPCol II-M significantly enhanced motor function recovery, reduced glial scar formation, guided axonal regrowth through its channel-patterned architecture, and reduced inflammation by modulating the surrounding immune microenvironment. These findings highlight the critical role of the proposed patterned scaffolds in generating spinal cord organoids and the significant potential for regenerative treatment of SCI.