Functional immobilization of interferon-gamma induces neuronal differentiation of neural stem cells

Stem cell transplantation provides significant promise to regenerative strategies after injury in the central nervous system. Neural stem/progenitor cells (NSPCs) have been studied in terms of their regenerative capacity and their ability to differentiate into neurons when exposed to various soluble factors. In this study, interferon‐γ (IFN‐γ) was compared with brain‐derived neurotrophic factor (BDNF) and erythropoietin and was shown to be the best single growth factor for inducing neuronal differentiation from adult rat brain‐derived NSPCs. Next, IFN‐γ was surface immobilized to a methacrylamide chitosan (MAC) scaffold that was specifically designed to match the modulus of brain tissue and neuronal differentiation of NSPCs was examined in vitro by immunohistochemistry. Bioactive IFN‐γ was successfully immobilized and quantified by ELISA. Both soluble and immobilized IFN‐γ on MAC surfaces showed dose dependent neuronal differentiation with soluble saturation occurring at 100 ng/mL and the most effective immobilized IFN‐γ dose at 37.5 ng/cm2, where significantly more neurons resulted compared with controls including soluble IFN‐γ. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010