The potential of stem cells and tissue engineered scaffolds for repair of the central nervous system

Damage to the central nervous system (CNS) can have a devastating consequence due to the limited capacity for repair of the brain and spinal cord. The lack of treatment options available for CNS injury has resulted in increasing interest in stem cell therapies in the hope that they will provide symptomatic relief and/or slow disease progression. Stem cells have been identified as a possible cell source for transplantation due to their capacity to differentiate into many cell types, as well as their self-renewal properties. Transplantation of stem cells has shown promising results for a variety of chronic and acute neural injuries; for both cell replacement as well as promoting endogenous repair. However, issues with graft survival, controlled differentiation as well as adequate reinnervation of host circuitry have hindered clinical development. In this regard, tissue engineering scaffolds offer a novel approach to stem cell therapies as they can be engineered to provide a physical and chemical milieu more suitable for implantation and long term integration of grafted cells. This chapter will highlight some of the current hurdles for stem cell therapies, focusing on cell replacement therapy (CRT), and address ways in which tissue engineering scaffolds may enhance these technologies for future clinical application.