Three-dimensional bioprinting sodium alginate/gelatin scaffold combined with neural stem cells and oligodendrocytes markedly promoting nerve regeneration after spinal cord injury

Accumulating research has indicated that the transplantation of combined stem cells and scaffolds is an effective method for spinal cord injury (SCI). The development of three-dimensional (3D) bioprinting technology can make the 3D scaffolds combined with cells more accurate and effective for SCI treatment. However, unmyelinated newborn nerve fibers have no nerve signaling conduction, hampering recovery of motor function. In this study, we designed and printed a type of sodium alginate/gelatin scaffold loaded with neural stem cells and oligodendrocytes, which were involved in the formation of the myelin sheaths of neural cell axons. In order to observe the effectiveness of this 3D bioprinting scaffold, we transplanted it into the completely transected rat spinal cord, and then immunofluorescence staining, hematoxylin–eosin staining and behavioral assessment were performed. The results showed that this 3D bioprinting scaffold markedly improved the hindlimb motor function and promoted nerve regeneration. These findings suggested that this novel 3D bioprinting scaffold was a good carrier for cells transplantation, thereby enhancing spinal cord repair following injury.