Adhesion and differentiation of neuronal cells on Zn-doped bioactive glasses

To verify the compatibility of rigid supports with neuronal cells for biomechanical application, we have evaluated the biocompatibility of Zn-doped bioglasses versus neuronal cell line SKNBE. Undifferentiated and retinoic acid-differentiated cells were used. We have observed that bioglasses doped with low concentration of Zn favored cell adhesion and proliferation of undifferentiated SKNBE neuronal cells, while the high Zn concentration strongly interfered with cell proliferation. Instead the high Zn concentration lightly stimulates the adhesive and strongly stimulates the phenotype characterization of differentiated SKNBE cells. Focal contact sites were observed in cells performing spread adhesive morphology, while they were down-regulated in cells performing differentiation behavior. GAP-43 and neurofilament were expressed in differentiated cells. However, GAP-43 was also found to be expressed in undifferentiated cells, where its expression seems related to proliferative behavior of cells. This work evidenced the importance of the biomaterial chemical structure in influencing proliferation or differentiation pathways of neuronal cells.