Silicon or Silicon Carbide surface as novel cell culture device for neural stem cells

Silicon (Si) wafers have attracted considerable scientific interest as a promising biomaterial for the manufacture of implantable medical devices in the neurodegenerative diseases. Since the use of Si involves responsibilities due to its toxicity, the investigation is moving towards a new class of composite semiconductors, such as the Silicon Carbide (3C-SiC). The main concerns in the material research for biomedical applications is to find a suitable material that produces low or no adverse effect when grafted in the body. Si has always been the preferred substrate material for micro-devices due to its low cost and ready availability, but it has several drawbacks that limit its use in biomedical applications, specifically when used in vivo. On the contrary, 3C-SiC results a good material for these purposes being biocompatible and hemo-compatible. The aim of our work was to test the biocompatibility levels of Si and 3C-SiC in an in vitro model of neural cells derived from both human dental pulp mesenchymal stem cells (DP-NSCs) and mouse Olfactory Ensheathing Cells (OECs), a particular glial cell type showing stem cell characteristics. To assess the biocompatibility of these substrates, we investigated the mitochondrial membrane potential, cytotoxicity and morphological changes through Scanning Electron Microscope analysis. Moreover, we assessed the expression of some markers, such as Nestin, GFAP, S-100, MAP2 and Neurofilament by immunocytochemical procedures. Our results demonstrate that 3C-SiC avoids cell stress both on DP-NSCs and OECs, in addition we found that it was not visible adverse reaction on both mitochondrial membrane potential and morphological modifications. A significant regulation of gene expression was found by qRT-PCR assay in neuronal cells differentiated from DPSC. Therefore, this study shows that 3C-SiC might represented a valid support in long-term implantable biochips having a biocompatibility that overlap with that obtained with other carbon-derived materials. In addition, the synergistic effect of cell transplantation and biomaterial supports implantation could be considered as a promising insight for nerve injury treatment. In conclusion, our findings highlight the possibility to use, as clinical tool for lesioned neural areas, Neural Stem Cells plated on 3C-SiC substrate, indicating these strategies as a future perspective for the development of novel cell therapies that would reach from bench to bedside to serve the neuro-degenerated patients.