A bioengineered spinal cord is fabricated via extrusion-based multilateral 3D bioprinting, in which clusters of induced pluripotent stem cell (iPSC)-derived spinal neuronal progenitor cells (sNPCs) and oligodendrocyte progenitor cells (OPCs) are placed in precise positions within 3D printed biocompatible scaffolds during assembly. The location of a cluster of cells, of a single type or multiple types, is controlled using a point-dispensing printing method with a 200 μm center-to-center spacing within 150 μm wide channels. The bioprinted sNPCs differentiate and extend axons throughout microscale scaffold channels, and the activity of these neuronal networks is confirmed by physiological spontaneous calcium flux studies. Successful bioprinting of OPCs in combination with sNPCs demonstrates a multicellular neural tissue engineering approach, where the ability to direct the patterning and combination of transplanted neuronal and glial cells can be beneficial in rebuilding functional axonal connections across areas of central nervous system (CNS) tissue damage. This platform can be used to prepare novel biomimetic, hydrogel-based scaffolds modeling complex CNS tissue architecture in vitro and harnessed to develop new clinical approaches to treat neurological diseases, including spinal cord injury.
The ability to model CNS tissues in vitro for in vivo transplantation has the potential to be of critical importance in a variety of medical conditions such as spinal cord injury, traumatic brain injury, stroke, and degenerative neurologic disease. Our approach to generating functional CNS tissue constructs relies on a “multiprong” combination of sophisticated 3D bioprinting and cell culture expertise. Here, as an example for utilizing novel 3D neurobioprinting, we have devised a method to model the cytoarchitecture of spinal cord tissue.
Sponsorship: Conquer Paralysis Now; Minnesota Spinal Cord Injury and Traumatic Brain Injury Research Grant Program; National Institute of Biomedical Imaging and Bioengineering of the National Institutes of Health (Award No. 1DP2EB020537); CTSI KL2 Scholar Program of the National Institutes of Health (Award No. NIHCON000000033119-3002)