A cytotoxicity study of silicon oxycarbide nanowires as cell scaffold for biomedical applications

Nanowires are promising biomaterials in multiple clinical applications. The goal of this study was to investigate the cytotoxicity of carbon-doped silica nanowires (SiO_xC_y NWs) on a fibroblastic cell line in vitro.

SiO_xC_y NWs were grown on Si substrates by CVD process. Murine L929 fibroblasts were cultured in complete DMEM and indirect and direct cytotoxicity tests were performed in agreement with ISO 19003-5, by quantitating cell viability at MTT and chemiluminescent assay. Cell cultures were investigated at Scanning Electron Microscope (SEM) and immunocytochemistry to observe their morphology and investigate cell-NWs interactions. Furthermore, hemocompatibility with Platelet-rich Plasma was assayed at SEM and by ELISA assay.

SiOxCy NWs proved biocompatible and did not impair cell proliferation at contact assays. L929 were able to attach on NWs and proliferate. Most interestingly, L929 reorganised the NW scaffold by displacing the nanostructure and creating tunnels within the NW network. NWs moreover did not impair platelet activation and behaved similarly to flat SiO₂.

Our data show that SiOxCy NWs did not release cytotoxic species and acted as a viable and adaptable scaffold for fibroblastic cells, thus representing a promising platform for implantable devices.