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In the last few years, Silicon wafers have attracted considerable scientific interest as a promising biomaterial for medical applications for the manufacture of implantable medical devices as in the context of neurodegenerative diseases. Since the use of silicon involves responsibilities due to its toxicity, the investigation is moving towards a new class of composite semiconductors, including 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, that can be implanted for long term and are capable of interfacing with electronic devices. In the field of semiconductors, Silicon (Si) has always been the preferred substrate material for micro-devices due to its low cost and ready availability (1). The aim of our work has been to test the biocompatibility levels of Si and 3C-SiC in an in vitro model of human neurons derived from dental pulp mesenchymal stem cells (DP-NSCs) (2,3) and murine Olfactory Ensheathing Cells (OECs), a particular glial cell type derived from olfactory bulbs, which shows stem cell characteristics (4). To assess the biocompatibility of these substrates, we investigated the mitochondrial membrane potential, cytotoxicity and morphological changes. Moreover, we assessed by immunocytochemical assay the expression of markers, such as Nestin, as stem cell marker, GFAP, as astroglial cell marker, S-100, as specific OEC marker and MAP2 and Neurofilament, as neuronal cytoscheletric markers. We found that the 3C-SiC avoided the oxidative stress and it was not visible adverse reaction on mitochondrial membrane potential and morphological modification. In addition, our results demonstrate that 3C-SiC avoids cell stress both on DP-NSCs and OECs. Therefore, this study demonstrates that 3C-SiC might be proposed as a valid support in the production of 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 new insight for nerve injury treatment. In conclusion, our findings highlight the possibility to use as clinical tool for lesioned neural areas Neuronal Stem Cells, NSC-DPSC or OECs 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.

In literature there are many evidences suggesting the ability of high frequency (3 MHz - 300 GHz) electromagnetic fields to influence biological systems, interfering with some regulation and control processes. However, up to date, the action mechanisms are not well understood. It should better clarified their connection with the characteristics of the impinging electromagnetic field, that is Specific Absorption Rate (SAR), exposure time (chronic or acute), frequency and type of modulation [1, 2, 3]. In these contribution, we present the first results assessing the non-thermal effects induced by exposure on primary Olfactory Ensheathing Cells (OECs) to continuous and amplitude modulated 900 MHz EMF, in far field condition and at different time expositions (10, 15, 20 minutes). OECs are typical glial cells showing characteristics of stem cells. They express several growth factors, are able to promote axonal regeneration and functional restoration in the injured sites of Central Nervous System [4]. Furthermore, since it is known that a reduced functionality of olfactory system represents an early sign of neurodegeneration. The OECs were isolated from olfactory from bulb of 2-day old mouse pups and divided into three groups (control, sham and tests). The control samples were kept in the incubator at 37 ° C in an environment of humidified air and CO2 (95% -5%). Sham and tests were placed in a thermostatic bath, appropriately realized, at 37°C for the duration of the exposure. As sham, it is intended a sample treated as test samples but not exposed to EMFs. The tests were exposed in far-field conditions to EMFs at 900 MHz continuous (CW 900 MHZ) and amplitude modulated at 50 Hz (AW 900 MHz), electromagnetic wave amplitude ~ 7 V / m in both exposure modes, and at three exposure times: 10, 15 and 20 minutes. The expression of the marker proteins of the OECs (S-100 and Nestin) and of the cytoskeletal proteins (GFAP and Vimentin) was evaluated by immunocytochemistry, as well as the cell viability by MTT test. The experimental results showed that the exposure to the CEM-RF used was able to induce a significant decrease in cell viability, changes in morphology and expression of the analyzed markers compared to the control cell cultures (incubator and sham). Surprisingly, these effects show a kinetic as function of time exposition and on the presence or absence of amplitude modulation. Studies are now in progress to better clarify the molecular mechanisms induced by EMF on OECs, in order to highlight also the involvement of glutamate receptors.

A tutt'oggi non sono chiari i meccanismi di natura non termica alla base dei danni indotti da campi elettromagnetici a radiofrequenza (CEM-RF) e microonde riscontrati negli studi in vitro e in vivo. Al fine di valutare l'influenza dei CEM-RF, bassa intensità e tempi brevi di esposizione su colture di cellule neurali, abbiamo utilizzato culture di cellule primarie della mucosa olfattiva (OEC), tipiche cellule gliali aventi caratteristiche di staminalità, in grado di esprimere fattori di crescita e promuovere la rigenerazione assonale nei siti danneggiati del sistema nervoso. Le OEC sono state preparate a partire da bulbi olfattivi di ratto e divisi in tre gruppi (controllo, sham e test). I controlli sono stati mantenuti nell'incubatore a 37°C in ambiente di aria umidificata e CO2 (95%-5%), mentre i campioni di sham e test sono stati collocati in bagnetto termico termostatato a 37°C per la durata della esposizione. Lo sham è un campione di controllo trattato come i campioni di test ma non esposto a CEM-RF. I campioni di test sono stati esposti in condizioni di campo lontano a CEM-RF a 900 MHz in continua e modulati in ampiezza a 50 Hz (indice modulazione m_a=0.27), intensità del campo elettromagnetico pari a circa 7 V/m in entrambe le modalità di esposizione, a tre diversi tempi di esposizione: 10, 15 e 20 minuti. Di ciascun campione è stata valutata sia l'espressione delle proteine marker delle OEC (S-100 e Nestina) sia delle proteine citoscheletriche (GFAP e Vimentina) tramite test di immunocitochimica, nonché la vitalità cellulare tramite test MTT. I risultati sperimentali hanno dimostrato che l'esposizione ai CEM-RF utilizzati è in grado di indurre una significativa diminuzione della vitalità cellulare, cambiamenti nella morfologia e nella espressione dei marker analizzati rispetto alle colture cellulari di controllo (incubatore e sham). Sorprendentemente questi effetti sembrano dipendere dalla presenza o meno della modulazione di ampiezza.