Low concentration of serum helps to maintain the characteristics of NSCs/NPCs on alkali-treated PHBHHx film in vitro.

Efforts have been made by tissue engineers to create a permissive environment for neural regeneration, and to enhance the efficiency of neural stem cell (NSC) transplantation. However, to acquire sufficient number of seed cells on the material appears to be the main obstacle to constructing functional transplantable NSC-biomaterial complexes. A culture system has been optimized in the current study to maintain the specific characteristics of NSCs/neural progenitor cells (NPCs) on the material and achieve sustaining increased multipotent seed cells. The PHBHHx film was selected as biomaterial and the surface was firstly modified with NaOH treatment. The NSCs/NPCs isolated from the cerebral cortex of rat embryos were cultured on the treated PHBHHx films in growth medium containing 1%, 5%, and 10% fetal bovine serum (FBS). Then the attachment, survival, proliferation, and differentiation of NSCs/NPCs were assessed. NaOH treatment significantly increased the hydrophilicity of PHBHHx and enhanced NSCs/NPCs attachment. On the treated PHBHHx film, NSCs/NPCs survived well and actively proliferated in the medium containing 1% FBS. After 7-14 days in culture, approximately two-thirds of cells remained as nestin and Sox2 positive NSCs/NPCs. However, in the medium containing 5% and 10% FBS, NSCs/NPCs proliferation was reduced and differentiation, particularly glial differentiation was significantly promoted. Growth medium containing low concentration of FBS is favorable for maintaining the characteristics, in terms of self-renewal and multiple differentiation, of NSCs/NPCs on NaOH-treated PHBHHx films. This could be a useful method to construct functional transplantable NSCs/NPCs-biomaterial complex.