The Role Of Graphene Substrates To The Development And Function Of Neural Stem Cells

In order to govern cell-specific behaviors in neural tissue engineering for neural repair and regeneration, a better understanding of material-cell interactions, especially the bioelectric functions, is extremely important. Graphene has been reported to be a potential candidate for use as a scaffold and neural interfacing material. However, the bioelectric evolvement of cell membranes on these conductive graphene substrates remains largely uninvestigated. Neural stem cells (NSCs)) play a vital role in neural repair and regeneration because of their potential of which can differentiate to neurons, astrocytes and oligodendrocytes. In this study, a NSC model was used to explore the possible changes in membrane bioelectric properties-including resting membrane potentials and action potentials-and cell behaviors on graphene films under both proliferation and differentiation conditions. The method we used was a combination of single-cell electrophysiological recordings and traditional cell biology techniques. As shown in our study, graphene did not affect the basic membrane electrical parameters (capacitance and input resistance), but resting membrane potentials of cells on graphene substrates were more strongly negative under both proliferation and differentiation conditions. Also, NSCs and their progeny on graphene substrates exhibited increased firing of action potentials during development compared to controls. However, graphene only slightly affected the electric characterizations of mature NSC progeny. The modulation of passive and active bioelectric properties on the graphene substrate was accompanied by enhanced NSC differentiation. Moreover, modeling of the electric field on conductive graphene substrates suggests that the electric field produced by the electronegative cell membrane is much higher on graphene substrates than that on control, and this might explain the observed changes of bioelectric development by graphene coupling. Our results indicate that graphene is able to accelerate NSC maturation during development, especially with regard to bioelectric evolvement. And our findings provide a fundamental understanding of the role of conductive materials in tuning the membrane bioelectric properties in a graphene model and pave the way for future studies on the development of methods and materials for manipulating membrane properties in a controllable way for NSC-based therapies.