Harnessing stem cells and biomaterials to promote neural repair

With the limited capacity for self-repair in the adult CNS, efforts to stimulate quiescent stem cell populations within discrete brain regions, as well as harness the potential of stem cell transplants, offer significant hope for neural repair. These new cells are capable of providing trophic cues to support residual host populations and/or replace those cells lost to the primary insult. However, issues with low-level adult neurogenesis, cell survival, directed differentiation and inadequate reinnervation of host tissue have impeded the full potential of these therapeutic approaches and their clinical advancement. Biomaterials offer novel approaches to stimulate endogenous neurogenesis, as well as for the delivery and support of neural progenitor transplants, providing a tissue-appropriate physical and trophic milieu for the newly integrating cells. In this review, we will discuss the various approaches by which bioengineered scaffolds may improve stem cell-based therapies for repair of the CNS.