Porous chitosan scaffold and ngf promote neuronal differentiation of neural stem cells in vitro.

Successful neural stem cells (NSCs) therapies require the controlled differentiation of NSCs into neurons. Porous chitosan scaffold was explored if it promoted neuronal differentiation of NSCs in the presence of nerve growth factor (NGF) in 3-dimensional (3-D) culture.Chitosan scaffold was made by the freeze-drying technique. NSCs were cultured under four different conditions: on flat cover slips (2-D structure) in media with or without NGF, and on chitosan scaffold (3-D structure) in media with or without NGF. Immunohistochemical staining was used to observe multi-directional differentiation of cultured NSCs. Photomicrographs were taken and analyzed for cell number, soma size, and neuronal process length.The porosity index of chitosan scaffold was around 90% and the diameter of pores was 50-350 μm. NSCs could differentiate into neurons, astrocytes, and oligodendrocytes under all culture conditions. The rank efficacy for neuronal differentiation was 3-D culture with NGF group > 3-D culture without NGF group > 2-D culture with NGF group > 2-D culture without NGF group.The results suggest that the combination of chitosan scaffold and NGF exerts a synergistic effect on neuronal differentiation of NSCs, a requirement for successful integration into the damaged central nervous system.