The effect of chitosan and PVDF substrates on the behavior of embryonic rat cerebral cortical stem cells

In this study, the behavior of neural stem cells from embryonic rat cerebral cortex were compared on the chitosan and poly(vinylidene fluoride) (PVDF) substrates at single-cell and neurosphere level. It was found that chitosan and PVDF substrates inhibited the proliferation and differentiation of single neural stem cells. It seemed that single-cell cultures on both substrates show cells remained dormant. However, neurospheres could exhibit different or similar behavior on these two substrates, which is dependent on the presence or absence of serum. More cells migrated outside from the neurospheres and longer processes extended from differentiated cells on chitosan than on PVDF when neurospheres were cultured in the serum-free medium. On the contrary, when serum was added to the culture system, chitosan and PVDF could induce the neurosphere-forming cells into an extensive cellular substratum of protoplasmic cells upon which process-bearing cells spread. In addition, based on the immunocytochemical analysis, the percentages of differentiated cell phenotypes of neurospheres cultured on chitosan and PVDF substrates became similar in the presence of serum. Therefore, it is reasonable to suggest that biomaterials may stimulate or inhibit the proliferation and differentiation of neural stem cells according to the complex environmental conditions. The information presented here should be useful for the development of biomaterials to regulate the preservation, proliferation, and differentiation of neural stem cells.