Nanostructured zirconia surface induce differentiation and maturation events in neonatal neuronal cells from rat hippocampus

BACKGROUND-AIM Biomaterials with a positive impact on neurogenic processes could give a valuable contribution to prospective cell replacement therapies for neurodegenerative diseases. The idea behind is the in vitro recapitulation of neurogenesis for the substitution of damaged neurons by healthy ones. In general, the capacity of biomaterials to favour differentiation-promoting effects relies on the cellular competence for mechanotransduction, the perception of biophysical signals (i.e. rigidity and topography) and their conversion into biochemical cellular responses. So far most approaches in the context of neuronal cells were based on the modulation of substrate rigidity. Here we present the possibility to promote neuron differentiation and maturation by appropriate nanorough zirconia surfaces produced by supersonic cluster beam deposition (SCBD). METHODS Via quantitative shotgun proteomic analysis, we compared the protein profile of hippocampal cells interacting for 3 days with the differentiation-promoting nanorough zirconia surface with the cells grown on glass kept as control. An Anova test (FDR 0.05) was carried out to identify proteins differently expressed among different conditions. RESULTS In total almost 600 proteins were altered in their expression level. There was a quite drastic change of the cellular program versus mature neurons. Infact, neonatal rat hippocampal neuronal cells showed accelerated and enhanced maturation and synaptogenesis on these surfaces. This was demonstrated by the earlier and stronger presence of synaptic markers, electrophysiological activity on the single cell and network level and a protein profile confirming an advanced state of neurogenic events. Congruent to the nature of the biophysical signal input, the proteomic data also suggested a strong involvement of cytoskeleton- and integrin adhesome-related processes. CONCLUSIONS Our results strongly indicate a promising potential of nanotopographic features of these surfaces in supporting pivotal neuronal differentiation processes.