The emergence of several cell based therapy candidates in the clinic is an encouraging sign for human diseases/disorders that currently have no effective small molecule or biologic based therapy. Stem cells – including adult and pluripotent subtypes – offer tremendous clinical promise for the treatment of a variety of degenerative diseases, as these cells have the capacity to self-renew indefinitely and to mature into functional cell types and thereby serve as a source of cell replacement therapies (CRTs) and pluripotent stem cells (hPSCs) are of increasing interest for the development of CRTs because of their capacity to differentiate into all cell types in an adult, for which adult tissue-specific stem cells may in some cases not even exist. One potential CRT enabled by hPSCs is oligodendrocyte progenitor cells (OPCs) for the treatment of spinal cord injury (SCI). Such hPSC-OPCs have recently advanced to a Phase II clinical trial and are even being considered for additional diseases in the central nervous system (CNS), such as multiple sclerosis (MS), or injury from radiation. UC researchers have developed a microscale 3D culture screening and analysis methodology that is relevant to the production of several up and coming cell replacement therapy candidates for which derivation from a precursor cell type requires searching through a large in vitro design space of doses, durations, dynamics, and combinations of signaling cues over several weeks of culture, such as oligodendrocyte progenitor cells (OPCs) and midbrain dopaminergic neurons (mDA neurons) derived from human pluripotent stem cells.